Index: head/share/man/man9/vmem.9 =================================================================== --- head/share/man/man9/vmem.9 (revision 347948) +++ head/share/man/man9/vmem.9 (revision 347949) @@ -1,315 +1,312 @@ .\" $NetBSD: vmem.9,v 1.15 2013/01/29 22:02:17 wiz Exp $ .\" .\" Copyright (c)2006 YAMAMOTO Takashi, .\" All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .\" $FreeBSD$ .\" .\" ------------------------------------------------------------ -.Dd July 12, 2013 +.Dd May 17, 2019 .Dt VMEM 9 .Os .\" ------------------------------------------------------------ .Sh NAME .Nm vmem .Nd general purpose resource allocator .\" ------------------------------------------------------------ .Sh SYNOPSIS .In sys/vmem.h .\" - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - .Ft vmem_t * .Fn vmem_create \ "const char *name" "vmem_addr_t base" "vmem_size_t size" "vmem_size_t quantum" \ "vmem_size_t qcache_max" "int flags" .\" - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - .Ft int .Fn vmem_add \ "vmem_t *vm" "vmem_addr_t addr" "vmem_size_t size" "int flags" .\" - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - .Ft int .Fn vmem_xalloc \ "vmem_t *vm" "const vmem_size_t size" "vmem_size_t align" \ "const vmem_size_t phase" "const vmem_size_t nocross" \ "const vmem_addr_t minaddr" "const vmem_addr_t maxaddr" "int flags" \ "vmem_addr_t *addrp" .\" - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - .Ft void .Fn vmem_xfree "vmem_t *vm" "vmem_addr_t addr" "vmem_size_t size" .\" - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - .Ft int .Fn vmem_alloc "vmem_t *vm" "vmem_size_t size" "int flags" "vmem_addr_t *addrp" .\" - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - .Ft void .Fn vmem_free "vmem_t *vm" "vmem_addr_t addr" "vmem_size_t size" .\" - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - .Ft void .Fn vmem_destroy "vmem_t *vm" .\" ------------------------------------------------------------ .Sh DESCRIPTION The .Nm is a general purpose resource allocator. Despite its name, it can be used for arbitrary resources other than virtual memory. .Pp .\" - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - .Fn vmem_create creates a new vmem arena. .Bl -tag -width qcache_max .It Fa name The string to describe the vmem. .It Fa base The start address of the initial span. Pass .Dv 0 if no initial span is required. .It Fa size The size of the initial span. Pass .Dv 0 if no initial span is required. .It Fa quantum The smallest unit of allocation. .It Fa qcache_max The largest size of allocations which can be served by quantum cache. It is merely a hint and can be ignored. .It Fa flags -Combination of .Xr malloc 9 -wait flag and -.Nm -allocation strategy flag: -.Bl -tag -width M_FIRSTFIT -.It Dv M_FIRSTFIT -Prefer allocation performance. -.It Dv M_BESTFIT -Prefer space efficiency. +wait flag. .El -.El .Pp .\" - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - .Fn vmem_add adds a span of size .Fa size starting at .Fa addr to the arena. Returns 0 on success, .Dv ENOMEM on failure. .Fa flags is .Xr malloc 9 wait flag. .Pp .\" - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - .Fn vmem_xalloc allocates a resource from the arena. .Bl -tag -width nocross .It Fa vm The arena which we allocate from. .It Fa size Specify the size of the allocation. .It Fa align If zero, don't care about the alignment of the allocation. Otherwise, request a resource segment starting at offset .Fa phase from an .Fa align aligned boundary. .It Fa phase See the above description of .Fa align . If .Fa align is zero, .Fa phase should be zero. Otherwise, .Fa phase should be smaller than .Fa align . .It Fa nocross Request a resource which doesn't cross .Fa nocross aligned boundary. .It Fa minaddr Specify the minimum address which can be allocated, or .Dv VMEM_ADDR_MIN if the caller does not care. .It Fa maxaddr Specify the maximum address which can be allocated, or .Dv VMEM_ADDR_MAX if the caller does not care. .It Fa flags A bitwise OR of an allocation strategy and a .Xr malloc 9 wait flag. -The allocation strategy is one of -.Dv M_FIRSTFIT -and -.Dv M_BESTFIT . +The allocation strategy is one of: +.Bl -tag width indent +.It Dv M_FIRSTFIT +Prefer allocation performance. +.It Dv M_BESTFIT +Prefer space efficiency. +.It Dv M_NEXTFIT +Perform an address-ordered search for free addresses, beginning where +the previous search ended. +.El .It Fa addrp On success, if .Fa addrp is not .Dv NULL , .Fn vmem_xalloc overwrites it with the start address of the allocated span. .El .Pp .\" ------------------------------------------------------------ .Fn vmem_xfree frees resource allocated by .Fn vmem_xalloc to the arena. .Bl -tag -width addr .It Fa vm The arena which we free to. .It Fa addr The resource being freed. It must be the one returned by .Fn vmem_xalloc . Notably, it must not be the one from .Fn vmem_alloc . Otherwise, the behaviour is undefined. .It Fa size The size of the resource being freed. It must be the same as the .Fa size argument used for .Fn vmem_xalloc . .El .Pp .\" - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - .Fn vmem_alloc allocates a resource from the arena. .Bl -tag -width flags .It Fa vm The arena which we allocate from. .It Fa size Specify the size of the allocation. .It Fa flags A bitwise OR of an .Nm allocation strategy flag (see above) and a .Xr malloc 9 sleep flag. .It Fa addrp On success, if .Fa addrp is not .Dv NULL , .Fn vmem_alloc overwrites it with the start address of the allocated span. .El .Pp .\" - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - .Fn vmem_free frees resource allocated by .Fn vmem_alloc to the arena. .Bl -tag -width addr .It Fa vm The arena which we free to. .It Fa addr The resource being freed. It must be the one returned by .Fn vmem_alloc . Notably, it must not be the one from .Fn vmem_xalloc . Otherwise, the behaviour is undefined. .It Fa size The size of the resource being freed. It must be the same as the .Fa size argument used for .Fn vmem_alloc . .El .Pp .\" ------------------------------------------------------------ .Fn vmem_destroy destroys a vmem arena. .Bl -tag -width vm .It Fa vm The vmem arena being destroyed. The caller should ensure that no one will use it anymore. .El .\" ------------------------------------------------------------ .Sh RETURN VALUES .Fn vmem_create returns a pointer to the newly allocated vmem_t. Otherwise, it returns .Dv NULL . .Pp On success, .Fn vmem_xalloc and .Fn vmem_alloc return 0. Otherwise, .Dv ENOMEM is returned. .\" ------------------------------------------------------------ .Sh CODE REFERENCES The .Nm subsystem is implemented within the file .Pa sys/kern/subr_vmem.c . .\" ------------------------------------------------------------ .Sh SEE ALSO .Xr malloc 9 .Rs .%A Jeff Bonwick .%A Jonathan Adams .%T "Magazines and Vmem: Extending the Slab Allocator to Many CPUs and Arbitrary Resources" .%J "2001 USENIX Annual Technical Conference" .%D 2001 .Re .\" ------------------------------------------------------------ .Sh HISTORY The .Nm allocator was originally implemented in .Nx . It was introduced in .Fx 10.0 . .Sh AUTHORS .An -nosplit Original implementation of .Nm was written by .An "YAMAMOTO Takashi" . The .Fx port was made by .An "Jeff Roberson" . .Sh BUGS .Nm relies on .Xr malloc 9 , so it cannot be used as early during system bootstrap. Index: head/sys/kern/subr_vmem.c =================================================================== --- head/sys/kern/subr_vmem.c (revision 347948) +++ head/sys/kern/subr_vmem.c (revision 347949) @@ -1,1632 +1,1770 @@ /*- * SPDX-License-Identifier: BSD-2-Clause-FreeBSD * * Copyright (c)2006,2007,2008,2009 YAMAMOTO Takashi, * Copyright (c) 2013 EMC Corp. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ /* * From: * $NetBSD: vmem_impl.h,v 1.2 2013/01/29 21:26:24 para Exp $ * $NetBSD: subr_vmem.c,v 1.83 2013/03/06 11:20:10 yamt Exp $ */ /* * reference: * - Magazines and Vmem: Extending the Slab Allocator * to Many CPUs and Arbitrary Resources * http://www.usenix.org/event/usenix01/bonwick.html */ #include __FBSDID("$FreeBSD$"); #include "opt_ddb.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "opt_vm.h" #include #include #include #include #include #include #include #include #include #include #include #include #include int vmem_startup_count(void); #define VMEM_OPTORDER 5 #define VMEM_OPTVALUE (1 << VMEM_OPTORDER) #define VMEM_MAXORDER \ (VMEM_OPTVALUE - 1 + sizeof(vmem_size_t) * NBBY - VMEM_OPTORDER) #define VMEM_HASHSIZE_MIN 16 #define VMEM_HASHSIZE_MAX 131072 #define VMEM_QCACHE_IDX_MAX 16 -#define VMEM_FITMASK (M_BESTFIT | M_FIRSTFIT) +#define VMEM_FITMASK (M_BESTFIT | M_FIRSTFIT | M_NEXTFIT) -#define VMEM_FLAGS \ - (M_NOWAIT | M_WAITOK | M_USE_RESERVE | M_NOVM | M_BESTFIT | M_FIRSTFIT) +#define VMEM_FLAGS (M_NOWAIT | M_WAITOK | M_USE_RESERVE | M_NOVM | \ + M_BESTFIT | M_FIRSTFIT | M_NEXTFIT) #define BT_FLAGS (M_NOWAIT | M_WAITOK | M_USE_RESERVE | M_NOVM) #define QC_NAME_MAX 16 /* * Data structures private to vmem. */ MALLOC_DEFINE(M_VMEM, "vmem", "vmem internal structures"); typedef struct vmem_btag bt_t; TAILQ_HEAD(vmem_seglist, vmem_btag); LIST_HEAD(vmem_freelist, vmem_btag); LIST_HEAD(vmem_hashlist, vmem_btag); struct qcache { uma_zone_t qc_cache; vmem_t *qc_vmem; vmem_size_t qc_size; char qc_name[QC_NAME_MAX]; }; typedef struct qcache qcache_t; #define QC_POOL_TO_QCACHE(pool) ((qcache_t *)(pool->pr_qcache)) #define VMEM_NAME_MAX 16 +/* boundary tag */ +struct vmem_btag { + TAILQ_ENTRY(vmem_btag) bt_seglist; + union { + LIST_ENTRY(vmem_btag) u_freelist; /* BT_TYPE_FREE */ + LIST_ENTRY(vmem_btag) u_hashlist; /* BT_TYPE_BUSY */ + } bt_u; +#define bt_hashlist bt_u.u_hashlist +#define bt_freelist bt_u.u_freelist + vmem_addr_t bt_start; + vmem_size_t bt_size; + int bt_type; +}; + /* vmem arena */ struct vmem { struct mtx_padalign vm_lock; struct cv vm_cv; char vm_name[VMEM_NAME_MAX+1]; LIST_ENTRY(vmem) vm_alllist; struct vmem_hashlist vm_hash0[VMEM_HASHSIZE_MIN]; struct vmem_freelist vm_freelist[VMEM_MAXORDER]; struct vmem_seglist vm_seglist; struct vmem_hashlist *vm_hashlist; vmem_size_t vm_hashsize; /* Constant after init */ vmem_size_t vm_qcache_max; vmem_size_t vm_quantum_mask; vmem_size_t vm_import_quantum; int vm_quantum_shift; /* Written on alloc/free */ LIST_HEAD(, vmem_btag) vm_freetags; int vm_nfreetags; int vm_nbusytag; vmem_size_t vm_inuse; vmem_size_t vm_size; vmem_size_t vm_limit; + struct vmem_btag vm_cursor; /* Used on import. */ vmem_import_t *vm_importfn; vmem_release_t *vm_releasefn; void *vm_arg; /* Space exhaustion callback. */ vmem_reclaim_t *vm_reclaimfn; /* quantum cache */ qcache_t vm_qcache[VMEM_QCACHE_IDX_MAX]; }; -/* boundary tag */ -struct vmem_btag { - TAILQ_ENTRY(vmem_btag) bt_seglist; - union { - LIST_ENTRY(vmem_btag) u_freelist; /* BT_TYPE_FREE */ - LIST_ENTRY(vmem_btag) u_hashlist; /* BT_TYPE_BUSY */ - } bt_u; -#define bt_hashlist bt_u.u_hashlist -#define bt_freelist bt_u.u_freelist - vmem_addr_t bt_start; - vmem_size_t bt_size; - int bt_type; -}; - #define BT_TYPE_SPAN 1 /* Allocated from importfn */ #define BT_TYPE_SPAN_STATIC 2 /* vmem_add() or create. */ #define BT_TYPE_FREE 3 /* Available space. */ #define BT_TYPE_BUSY 4 /* Used space. */ +#define BT_TYPE_CURSOR 5 /* Cursor for nextfit allocations. */ #define BT_ISSPAN_P(bt) ((bt)->bt_type <= BT_TYPE_SPAN_STATIC) #define BT_END(bt) ((bt)->bt_start + (bt)->bt_size - 1) #if defined(DIAGNOSTIC) static int enable_vmem_check = 1; SYSCTL_INT(_debug, OID_AUTO, vmem_check, CTLFLAG_RWTUN, &enable_vmem_check, 0, "Enable vmem check"); static void vmem_check(vmem_t *); #endif static struct callout vmem_periodic_ch; static int vmem_periodic_interval; static struct task vmem_periodic_wk; static struct mtx_padalign __exclusive_cache_line vmem_list_lock; static LIST_HEAD(, vmem) vmem_list = LIST_HEAD_INITIALIZER(vmem_list); static uma_zone_t vmem_zone; /* ---- misc */ #define VMEM_CONDVAR_INIT(vm, wchan) cv_init(&vm->vm_cv, wchan) #define VMEM_CONDVAR_DESTROY(vm) cv_destroy(&vm->vm_cv) #define VMEM_CONDVAR_WAIT(vm) cv_wait(&vm->vm_cv, &vm->vm_lock) #define VMEM_CONDVAR_BROADCAST(vm) cv_broadcast(&vm->vm_cv) #define VMEM_LOCK(vm) mtx_lock(&vm->vm_lock) #define VMEM_TRYLOCK(vm) mtx_trylock(&vm->vm_lock) #define VMEM_UNLOCK(vm) mtx_unlock(&vm->vm_lock) #define VMEM_LOCK_INIT(vm, name) mtx_init(&vm->vm_lock, (name), NULL, MTX_DEF) #define VMEM_LOCK_DESTROY(vm) mtx_destroy(&vm->vm_lock) #define VMEM_ASSERT_LOCKED(vm) mtx_assert(&vm->vm_lock, MA_OWNED); #define VMEM_ALIGNUP(addr, align) (-(-(addr) & -(align))) #define VMEM_CROSS_P(addr1, addr2, boundary) \ ((((addr1) ^ (addr2)) & -(boundary)) != 0) #define ORDER2SIZE(order) ((order) < VMEM_OPTVALUE ? ((order) + 1) : \ (vmem_size_t)1 << ((order) - (VMEM_OPTVALUE - VMEM_OPTORDER - 1))) #define SIZE2ORDER(size) ((size) <= VMEM_OPTVALUE ? ((size) - 1) : \ (flsl(size) + (VMEM_OPTVALUE - VMEM_OPTORDER - 2))) /* * Maximum number of boundary tags that may be required to satisfy an * allocation. Two may be required to import. Another two may be * required to clip edges. */ #define BT_MAXALLOC 4 /* * Max free limits the number of locally cached boundary tags. We * just want to avoid hitting the zone allocator for every call. */ #define BT_MAXFREE (BT_MAXALLOC * 8) /* Allocator for boundary tags. */ static uma_zone_t vmem_bt_zone; /* boot time arena storage. */ static struct vmem kernel_arena_storage; static struct vmem buffer_arena_storage; static struct vmem transient_arena_storage; /* kernel and kmem arenas are aliased for backwards KPI compat. */ vmem_t *kernel_arena = &kernel_arena_storage; vmem_t *kmem_arena = &kernel_arena_storage; vmem_t *buffer_arena = &buffer_arena_storage; vmem_t *transient_arena = &transient_arena_storage; #ifdef DEBUG_MEMGUARD static struct vmem memguard_arena_storage; vmem_t *memguard_arena = &memguard_arena_storage; #endif /* * Fill the vmem's boundary tag cache. We guarantee that boundary tag * allocation will not fail once bt_fill() passes. To do so we cache * at least the maximum possible tag allocations in the arena. */ static int bt_fill(vmem_t *vm, int flags) { bt_t *bt; VMEM_ASSERT_LOCKED(vm); /* * Only allow the kernel arena and arenas derived from kernel arena to * dip into reserve tags. They are where new tags come from. */ flags &= BT_FLAGS; if (vm != kernel_arena && vm->vm_arg != kernel_arena) flags &= ~M_USE_RESERVE; /* * Loop until we meet the reserve. To minimize the lock shuffle * and prevent simultaneous fills we first try a NOWAIT regardless * of the caller's flags. Specify M_NOVM so we don't recurse while * holding a vmem lock. */ while (vm->vm_nfreetags < BT_MAXALLOC) { bt = uma_zalloc(vmem_bt_zone, (flags & M_USE_RESERVE) | M_NOWAIT | M_NOVM); if (bt == NULL) { VMEM_UNLOCK(vm); bt = uma_zalloc(vmem_bt_zone, flags); VMEM_LOCK(vm); if (bt == NULL) break; } LIST_INSERT_HEAD(&vm->vm_freetags, bt, bt_freelist); vm->vm_nfreetags++; } if (vm->vm_nfreetags < BT_MAXALLOC) return ENOMEM; return 0; } /* * Pop a tag off of the freetag stack. */ static bt_t * bt_alloc(vmem_t *vm) { bt_t *bt; VMEM_ASSERT_LOCKED(vm); bt = LIST_FIRST(&vm->vm_freetags); MPASS(bt != NULL); LIST_REMOVE(bt, bt_freelist); vm->vm_nfreetags--; return bt; } /* * Trim the per-vmem free list. Returns with the lock released to * avoid allocator recursions. */ static void bt_freetrim(vmem_t *vm, int freelimit) { LIST_HEAD(, vmem_btag) freetags; bt_t *bt; LIST_INIT(&freetags); VMEM_ASSERT_LOCKED(vm); while (vm->vm_nfreetags > freelimit) { bt = LIST_FIRST(&vm->vm_freetags); LIST_REMOVE(bt, bt_freelist); vm->vm_nfreetags--; LIST_INSERT_HEAD(&freetags, bt, bt_freelist); } VMEM_UNLOCK(vm); while ((bt = LIST_FIRST(&freetags)) != NULL) { LIST_REMOVE(bt, bt_freelist); uma_zfree(vmem_bt_zone, bt); } } static inline void bt_free(vmem_t *vm, bt_t *bt) { VMEM_ASSERT_LOCKED(vm); MPASS(LIST_FIRST(&vm->vm_freetags) != bt); LIST_INSERT_HEAD(&vm->vm_freetags, bt, bt_freelist); vm->vm_nfreetags++; } /* * freelist[0] ... [1, 1] * freelist[1] ... [2, 2] * : * freelist[29] ... [30, 30] * freelist[30] ... [31, 31] * freelist[31] ... [32, 63] * freelist[33] ... [64, 127] * : * freelist[n] ... [(1 << (n - 26)), (1 << (n - 25)) - 1] * : */ static struct vmem_freelist * bt_freehead_tofree(vmem_t *vm, vmem_size_t size) { const vmem_size_t qsize = size >> vm->vm_quantum_shift; const int idx = SIZE2ORDER(qsize); MPASS(size != 0 && qsize != 0); MPASS((size & vm->vm_quantum_mask) == 0); MPASS(idx >= 0); MPASS(idx < VMEM_MAXORDER); return &vm->vm_freelist[idx]; } /* * bt_freehead_toalloc: return the freelist for the given size and allocation * strategy. * * For M_FIRSTFIT, return the list in which any blocks are large enough * for the requested size. otherwise, return the list which can have blocks * large enough for the requested size. */ static struct vmem_freelist * bt_freehead_toalloc(vmem_t *vm, vmem_size_t size, int strat) { const vmem_size_t qsize = size >> vm->vm_quantum_shift; int idx = SIZE2ORDER(qsize); MPASS(size != 0 && qsize != 0); MPASS((size & vm->vm_quantum_mask) == 0); if (strat == M_FIRSTFIT && ORDER2SIZE(idx) != qsize) { idx++; /* check too large request? */ } MPASS(idx >= 0); MPASS(idx < VMEM_MAXORDER); return &vm->vm_freelist[idx]; } /* ---- boundary tag hash */ static struct vmem_hashlist * bt_hashhead(vmem_t *vm, vmem_addr_t addr) { struct vmem_hashlist *list; unsigned int hash; hash = hash32_buf(&addr, sizeof(addr), 0); list = &vm->vm_hashlist[hash % vm->vm_hashsize]; return list; } static bt_t * bt_lookupbusy(vmem_t *vm, vmem_addr_t addr) { struct vmem_hashlist *list; bt_t *bt; VMEM_ASSERT_LOCKED(vm); list = bt_hashhead(vm, addr); LIST_FOREACH(bt, list, bt_hashlist) { if (bt->bt_start == addr) { break; } } return bt; } static void bt_rembusy(vmem_t *vm, bt_t *bt) { VMEM_ASSERT_LOCKED(vm); MPASS(vm->vm_nbusytag > 0); vm->vm_inuse -= bt->bt_size; vm->vm_nbusytag--; LIST_REMOVE(bt, bt_hashlist); } static void bt_insbusy(vmem_t *vm, bt_t *bt) { struct vmem_hashlist *list; VMEM_ASSERT_LOCKED(vm); MPASS(bt->bt_type == BT_TYPE_BUSY); list = bt_hashhead(vm, bt->bt_start); LIST_INSERT_HEAD(list, bt, bt_hashlist); vm->vm_nbusytag++; vm->vm_inuse += bt->bt_size; } /* ---- boundary tag list */ static void bt_remseg(vmem_t *vm, bt_t *bt) { TAILQ_REMOVE(&vm->vm_seglist, bt, bt_seglist); bt_free(vm, bt); } static void bt_insseg(vmem_t *vm, bt_t *bt, bt_t *prev) { TAILQ_INSERT_AFTER(&vm->vm_seglist, prev, bt, bt_seglist); } static void bt_insseg_tail(vmem_t *vm, bt_t *bt) { TAILQ_INSERT_TAIL(&vm->vm_seglist, bt, bt_seglist); } static void bt_remfree(vmem_t *vm, bt_t *bt) { MPASS(bt->bt_type == BT_TYPE_FREE); LIST_REMOVE(bt, bt_freelist); } static void bt_insfree(vmem_t *vm, bt_t *bt) { struct vmem_freelist *list; list = bt_freehead_tofree(vm, bt->bt_size); LIST_INSERT_HEAD(list, bt, bt_freelist); } /* ---- vmem internal functions */ /* * Import from the arena into the quantum cache in UMA. * * We use VMEM_ADDR_QCACHE_MIN instead of 0: uma_zalloc() returns 0 to indicate * failure, so UMA can't be used to cache a resource with value 0. */ static int qc_import(void *arg, void **store, int cnt, int domain, int flags) { qcache_t *qc; vmem_addr_t addr; int i; KASSERT((flags & M_WAITOK) == 0, ("blocking allocation")); qc = arg; for (i = 0; i < cnt; i++) { if (vmem_xalloc(qc->qc_vmem, qc->qc_size, 0, 0, 0, VMEM_ADDR_QCACHE_MIN, VMEM_ADDR_MAX, flags, &addr) != 0) break; store[i] = (void *)addr; } return (i); } /* * Release memory from the UMA cache to the arena. */ static void qc_release(void *arg, void **store, int cnt) { qcache_t *qc; int i; qc = arg; for (i = 0; i < cnt; i++) vmem_xfree(qc->qc_vmem, (vmem_addr_t)store[i], qc->qc_size); } static void qc_init(vmem_t *vm, vmem_size_t qcache_max) { qcache_t *qc; vmem_size_t size; int qcache_idx_max; int i; MPASS((qcache_max & vm->vm_quantum_mask) == 0); qcache_idx_max = MIN(qcache_max >> vm->vm_quantum_shift, VMEM_QCACHE_IDX_MAX); vm->vm_qcache_max = qcache_idx_max << vm->vm_quantum_shift; for (i = 0; i < qcache_idx_max; i++) { qc = &vm->vm_qcache[i]; size = (i + 1) << vm->vm_quantum_shift; snprintf(qc->qc_name, sizeof(qc->qc_name), "%s-%zu", vm->vm_name, size); qc->qc_vmem = vm; qc->qc_size = size; qc->qc_cache = uma_zcache_create(qc->qc_name, size, NULL, NULL, NULL, NULL, qc_import, qc_release, qc, UMA_ZONE_VM); MPASS(qc->qc_cache); } } static void qc_destroy(vmem_t *vm) { int qcache_idx_max; int i; qcache_idx_max = vm->vm_qcache_max >> vm->vm_quantum_shift; for (i = 0; i < qcache_idx_max; i++) uma_zdestroy(vm->vm_qcache[i].qc_cache); } static void qc_drain(vmem_t *vm) { int qcache_idx_max; int i; qcache_idx_max = vm->vm_qcache_max >> vm->vm_quantum_shift; for (i = 0; i < qcache_idx_max; i++) zone_drain(vm->vm_qcache[i].qc_cache); } #ifndef UMA_MD_SMALL_ALLOC static struct mtx_padalign __exclusive_cache_line vmem_bt_lock; /* * vmem_bt_alloc: Allocate a new page of boundary tags. * * On architectures with uma_small_alloc there is no recursion; no address * space need be allocated to allocate boundary tags. For the others, we * must handle recursion. Boundary tags are necessary to allocate new * boundary tags. * * UMA guarantees that enough tags are held in reserve to allocate a new * page of kva. We dip into this reserve by specifying M_USE_RESERVE only * when allocating the page to hold new boundary tags. In this way the * reserve is automatically filled by the allocation that uses the reserve. * * We still have to guarantee that the new tags are allocated atomically since * many threads may try concurrently. The bt_lock provides this guarantee. * We convert WAITOK allocations to NOWAIT and then handle the blocking here * on failure. It's ok to return NULL for a WAITOK allocation as UMA will * loop again after checking to see if we lost the race to allocate. * * There is a small race between vmem_bt_alloc() returning the page and the * zone lock being acquired to add the page to the zone. For WAITOK * allocations we just pause briefly. NOWAIT may experience a transient * failure. To alleviate this we permit a small number of simultaneous * fills to proceed concurrently so NOWAIT is less likely to fail unless * we are really out of KVA. */ static void * vmem_bt_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *pflag, int wait) { vmem_addr_t addr; *pflag = UMA_SLAB_KERNEL; /* * Single thread boundary tag allocation so that the address space * and memory are added in one atomic operation. */ mtx_lock(&vmem_bt_lock); if (vmem_xalloc(vm_dom[domain].vmd_kernel_arena, bytes, 0, 0, 0, VMEM_ADDR_MIN, VMEM_ADDR_MAX, M_NOWAIT | M_NOVM | M_USE_RESERVE | M_BESTFIT, &addr) == 0) { if (kmem_back_domain(domain, kernel_object, addr, bytes, M_NOWAIT | M_USE_RESERVE) == 0) { mtx_unlock(&vmem_bt_lock); return ((void *)addr); } vmem_xfree(vm_dom[domain].vmd_kernel_arena, addr, bytes); mtx_unlock(&vmem_bt_lock); /* * Out of memory, not address space. This may not even be * possible due to M_USE_RESERVE page allocation. */ if (wait & M_WAITOK) vm_wait_domain(domain); return (NULL); } mtx_unlock(&vmem_bt_lock); /* * We're either out of address space or lost a fill race. */ if (wait & M_WAITOK) pause("btalloc", 1); return (NULL); } /* * How many pages do we need to startup_alloc. */ int vmem_startup_count(void) { return (howmany(BT_MAXALLOC, UMA_SLAB_SPACE / sizeof(struct vmem_btag))); } #endif void vmem_startup(void) { mtx_init(&vmem_list_lock, "vmem list lock", NULL, MTX_DEF); vmem_zone = uma_zcreate("vmem", sizeof(struct vmem), NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_VM); vmem_bt_zone = uma_zcreate("vmem btag", sizeof(struct vmem_btag), NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_VM | UMA_ZONE_NOFREE); #ifndef UMA_MD_SMALL_ALLOC mtx_init(&vmem_bt_lock, "btag lock", NULL, MTX_DEF); uma_prealloc(vmem_bt_zone, BT_MAXALLOC); /* * Reserve enough tags to allocate new tags. We allow multiple * CPUs to attempt to allocate new tags concurrently to limit * false restarts in UMA. vmem_bt_alloc() allocates from a per-domain * arena, which may involve importing a range from the kernel arena, * so we need to keep at least 2 * BT_MAXALLOC tags reserved. */ uma_zone_reserve(vmem_bt_zone, 2 * BT_MAXALLOC * mp_ncpus); uma_zone_set_allocf(vmem_bt_zone, vmem_bt_alloc); #endif } /* ---- rehash */ static int vmem_rehash(vmem_t *vm, vmem_size_t newhashsize) { bt_t *bt; int i; struct vmem_hashlist *newhashlist; struct vmem_hashlist *oldhashlist; vmem_size_t oldhashsize; MPASS(newhashsize > 0); newhashlist = malloc(sizeof(struct vmem_hashlist) * newhashsize, M_VMEM, M_NOWAIT); if (newhashlist == NULL) return ENOMEM; for (i = 0; i < newhashsize; i++) { LIST_INIT(&newhashlist[i]); } VMEM_LOCK(vm); oldhashlist = vm->vm_hashlist; oldhashsize = vm->vm_hashsize; vm->vm_hashlist = newhashlist; vm->vm_hashsize = newhashsize; if (oldhashlist == NULL) { VMEM_UNLOCK(vm); return 0; } for (i = 0; i < oldhashsize; i++) { while ((bt = LIST_FIRST(&oldhashlist[i])) != NULL) { bt_rembusy(vm, bt); bt_insbusy(vm, bt); } } VMEM_UNLOCK(vm); if (oldhashlist != vm->vm_hash0) { free(oldhashlist, M_VMEM); } return 0; } static void vmem_periodic_kick(void *dummy) { taskqueue_enqueue(taskqueue_thread, &vmem_periodic_wk); } static void vmem_periodic(void *unused, int pending) { vmem_t *vm; vmem_size_t desired; vmem_size_t current; mtx_lock(&vmem_list_lock); LIST_FOREACH(vm, &vmem_list, vm_alllist) { #ifdef DIAGNOSTIC /* Convenient time to verify vmem state. */ if (enable_vmem_check == 1) { VMEM_LOCK(vm); vmem_check(vm); VMEM_UNLOCK(vm); } #endif desired = 1 << flsl(vm->vm_nbusytag); desired = MIN(MAX(desired, VMEM_HASHSIZE_MIN), VMEM_HASHSIZE_MAX); current = vm->vm_hashsize; /* Grow in powers of two. Shrink less aggressively. */ if (desired >= current * 2 || desired * 4 <= current) vmem_rehash(vm, desired); /* * Periodically wake up threads waiting for resources, * so they could ask for reclamation again. */ VMEM_CONDVAR_BROADCAST(vm); } mtx_unlock(&vmem_list_lock); callout_reset(&vmem_periodic_ch, vmem_periodic_interval, vmem_periodic_kick, NULL); } static void vmem_start_callout(void *unused) { TASK_INIT(&vmem_periodic_wk, 0, vmem_periodic, NULL); vmem_periodic_interval = hz * 10; callout_init(&vmem_periodic_ch, 1); callout_reset(&vmem_periodic_ch, vmem_periodic_interval, vmem_periodic_kick, NULL); } SYSINIT(vfs, SI_SUB_CONFIGURE, SI_ORDER_ANY, vmem_start_callout, NULL); static void vmem_add1(vmem_t *vm, vmem_addr_t addr, vmem_size_t size, int type) { bt_t *btspan; bt_t *btfree; MPASS(type == BT_TYPE_SPAN || type == BT_TYPE_SPAN_STATIC); MPASS((size & vm->vm_quantum_mask) == 0); btspan = bt_alloc(vm); btspan->bt_type = type; btspan->bt_start = addr; btspan->bt_size = size; bt_insseg_tail(vm, btspan); btfree = bt_alloc(vm); btfree->bt_type = BT_TYPE_FREE; btfree->bt_start = addr; btfree->bt_size = size; bt_insseg(vm, btfree, btspan); bt_insfree(vm, btfree); vm->vm_size += size; } static void vmem_destroy1(vmem_t *vm) { bt_t *bt; /* * Drain per-cpu quantum caches. */ qc_destroy(vm); /* * The vmem should now only contain empty segments. */ VMEM_LOCK(vm); MPASS(vm->vm_nbusytag == 0); while ((bt = TAILQ_FIRST(&vm->vm_seglist)) != NULL) bt_remseg(vm, bt); if (vm->vm_hashlist != NULL && vm->vm_hashlist != vm->vm_hash0) free(vm->vm_hashlist, M_VMEM); bt_freetrim(vm, 0); VMEM_CONDVAR_DESTROY(vm); VMEM_LOCK_DESTROY(vm); uma_zfree(vmem_zone, vm); } static int vmem_import(vmem_t *vm, vmem_size_t size, vmem_size_t align, int flags) { vmem_addr_t addr; int error; if (vm->vm_importfn == NULL) return (EINVAL); /* * To make sure we get a span that meets the alignment we double it * and add the size to the tail. This slightly overestimates. */ if (align != vm->vm_quantum_mask + 1) size = (align * 2) + size; size = roundup(size, vm->vm_import_quantum); if (vm->vm_limit != 0 && vm->vm_limit < vm->vm_size + size) return (ENOMEM); /* * Hide MAXALLOC tags so we're guaranteed to be able to add this * span and the tag we want to allocate from it. */ MPASS(vm->vm_nfreetags >= BT_MAXALLOC); vm->vm_nfreetags -= BT_MAXALLOC; VMEM_UNLOCK(vm); error = (vm->vm_importfn)(vm->vm_arg, size, flags, &addr); VMEM_LOCK(vm); vm->vm_nfreetags += BT_MAXALLOC; if (error) return (ENOMEM); vmem_add1(vm, addr, size, BT_TYPE_SPAN); return 0; } /* * vmem_fit: check if a bt can satisfy the given restrictions. * * it's a caller's responsibility to ensure the region is big enough * before calling us. */ static int vmem_fit(const bt_t *bt, vmem_size_t size, vmem_size_t align, vmem_size_t phase, vmem_size_t nocross, vmem_addr_t minaddr, vmem_addr_t maxaddr, vmem_addr_t *addrp) { vmem_addr_t start; vmem_addr_t end; MPASS(size > 0); MPASS(bt->bt_size >= size); /* caller's responsibility */ /* * XXX assumption: vmem_addr_t and vmem_size_t are * unsigned integer of the same size. */ start = bt->bt_start; if (start < minaddr) { start = minaddr; } end = BT_END(bt); if (end > maxaddr) end = maxaddr; if (start > end) return (ENOMEM); start = VMEM_ALIGNUP(start - phase, align) + phase; if (start < bt->bt_start) start += align; if (VMEM_CROSS_P(start, start + size - 1, nocross)) { MPASS(align < nocross); start = VMEM_ALIGNUP(start - phase, nocross) + phase; } if (start <= end && end - start >= size - 1) { MPASS((start & (align - 1)) == phase); MPASS(!VMEM_CROSS_P(start, start + size - 1, nocross)); MPASS(minaddr <= start); MPASS(maxaddr == 0 || start + size - 1 <= maxaddr); MPASS(bt->bt_start <= start); MPASS(BT_END(bt) - start >= size - 1); *addrp = start; return (0); } return (ENOMEM); } /* * vmem_clip: Trim the boundary tag edges to the requested start and size. */ static void vmem_clip(vmem_t *vm, bt_t *bt, vmem_addr_t start, vmem_size_t size) { bt_t *btnew; bt_t *btprev; VMEM_ASSERT_LOCKED(vm); MPASS(bt->bt_type == BT_TYPE_FREE); MPASS(bt->bt_size >= size); bt_remfree(vm, bt); if (bt->bt_start != start) { btprev = bt_alloc(vm); btprev->bt_type = BT_TYPE_FREE; btprev->bt_start = bt->bt_start; btprev->bt_size = start - bt->bt_start; bt->bt_start = start; bt->bt_size -= btprev->bt_size; bt_insfree(vm, btprev); bt_insseg(vm, btprev, TAILQ_PREV(bt, vmem_seglist, bt_seglist)); } MPASS(bt->bt_start == start); if (bt->bt_size != size && bt->bt_size - size > vm->vm_quantum_mask) { /* split */ btnew = bt_alloc(vm); btnew->bt_type = BT_TYPE_BUSY; btnew->bt_start = bt->bt_start; btnew->bt_size = size; bt->bt_start = bt->bt_start + size; bt->bt_size -= size; bt_insfree(vm, bt); bt_insseg(vm, btnew, TAILQ_PREV(bt, vmem_seglist, bt_seglist)); bt_insbusy(vm, btnew); bt = btnew; } else { bt->bt_type = BT_TYPE_BUSY; bt_insbusy(vm, bt); } MPASS(bt->bt_size >= size); } +static int +vmem_try_fetch(vmem_t *vm, const vmem_size_t size, vmem_size_t align, int flags) +{ + vmem_size_t avail; + + VMEM_ASSERT_LOCKED(vm); + + /* + * XXX it is possible to fail to meet xalloc constraints with the + * imported region. It is up to the user to specify the + * import quantum such that it can satisfy any allocation. + */ + if (vmem_import(vm, size, align, flags) == 0) + return (1); + + /* + * Try to free some space from the quantum cache or reclaim + * functions if available. + */ + if (vm->vm_qcache_max != 0 || vm->vm_reclaimfn != NULL) { + avail = vm->vm_size - vm->vm_inuse; + VMEM_UNLOCK(vm); + if (vm->vm_qcache_max != 0) + qc_drain(vm); + if (vm->vm_reclaimfn != NULL) + vm->vm_reclaimfn(vm, flags); + VMEM_LOCK(vm); + /* If we were successful retry even NOWAIT. */ + if (vm->vm_size - vm->vm_inuse > avail) + return (1); + } + if ((flags & M_NOWAIT) != 0) + return (0); + VMEM_CONDVAR_WAIT(vm); + return (1); +} + +static int +vmem_try_release(vmem_t *vm, struct vmem_btag *bt, const bool remfree) +{ + struct vmem_btag *prev; + + MPASS(bt->bt_type == BT_TYPE_FREE); + + if (vm->vm_releasefn == NULL) + return (0); + + prev = TAILQ_PREV(bt, vmem_seglist, bt_seglist); + MPASS(prev != NULL); + MPASS(prev->bt_type != BT_TYPE_FREE); + + if (prev->bt_type == BT_TYPE_SPAN && prev->bt_size == bt->bt_size) { + vmem_addr_t spanaddr; + vmem_size_t spansize; + + MPASS(prev->bt_start == bt->bt_start); + spanaddr = prev->bt_start; + spansize = prev->bt_size; + if (remfree) + bt_remfree(vm, bt); + bt_remseg(vm, bt); + bt_remseg(vm, prev); + vm->vm_size -= spansize; + VMEM_CONDVAR_BROADCAST(vm); + bt_freetrim(vm, BT_MAXFREE); + vm->vm_releasefn(vm->vm_arg, spanaddr, spansize); + return (1); + } + return (0); +} + +static int +vmem_xalloc_nextfit(vmem_t *vm, const vmem_size_t size, vmem_size_t align, + const vmem_size_t phase, const vmem_size_t nocross, int flags, + vmem_addr_t *addrp) +{ + struct vmem_btag *bt, *cursor, *next, *prev; + int error; + + error = ENOMEM; + VMEM_LOCK(vm); +retry: + /* + * Make sure we have enough tags to complete the operation. + */ + if (vm->vm_nfreetags < BT_MAXALLOC && bt_fill(vm, flags) != 0) + goto out; + + /* + * Find the next free tag meeting our constraints. If one is found, + * perform the allocation. + */ + for (cursor = &vm->vm_cursor, bt = TAILQ_NEXT(cursor, bt_seglist); + bt != cursor; bt = TAILQ_NEXT(bt, bt_seglist)) { + if (bt == NULL) + bt = TAILQ_FIRST(&vm->vm_seglist); + if (bt->bt_type == BT_TYPE_FREE && bt->bt_size >= size && + (error = vmem_fit(bt, size, align, phase, nocross, + VMEM_ADDR_MIN, VMEM_ADDR_MAX, addrp)) == 0) { + vmem_clip(vm, bt, *addrp, size); + break; + } + } + + /* + * Try to coalesce free segments around the cursor. If we succeed, and + * have not yet satisfied the allocation request, try again with the + * newly coalesced segment. + */ + if ((next = TAILQ_NEXT(cursor, bt_seglist)) != NULL && + (prev = TAILQ_PREV(cursor, vmem_seglist, bt_seglist)) != NULL && + next->bt_type == BT_TYPE_FREE && prev->bt_type == BT_TYPE_FREE && + prev->bt_start + prev->bt_size == next->bt_start) { + prev->bt_size += next->bt_size; + bt_remfree(vm, next); + bt_remseg(vm, next); + + /* + * The coalesced segment might be able to satisfy our request. + * If not, we might need to release it from the arena. + */ + if (error == ENOMEM && prev->bt_size >= size && + (error = vmem_fit(prev, size, align, phase, nocross, + VMEM_ADDR_MIN, VMEM_ADDR_MAX, addrp)) == 0) { + vmem_clip(vm, prev, *addrp, size); + bt = prev; + } else + (void)vmem_try_release(vm, prev, true); + } + + /* + * If the allocation was successful, advance the cursor. + */ + if (error == 0) { + TAILQ_REMOVE(&vm->vm_seglist, cursor, bt_seglist); + for (; bt != NULL && bt->bt_start < *addrp + size; + bt = TAILQ_NEXT(bt, bt_seglist)) + ; + if (bt != NULL) + TAILQ_INSERT_BEFORE(bt, cursor, bt_seglist); + else + TAILQ_INSERT_HEAD(&vm->vm_seglist, cursor, bt_seglist); + } + + /* + * Attempt to bring additional resources into the arena. If that fails + * and M_WAITOK is specified, sleep waiting for resources to be freed. + */ + if (error == ENOMEM && vmem_try_fetch(vm, size, align, flags)) + goto retry; + +out: + VMEM_UNLOCK(vm); + return (error); +} + /* ---- vmem API */ void vmem_set_import(vmem_t *vm, vmem_import_t *importfn, vmem_release_t *releasefn, void *arg, vmem_size_t import_quantum) { VMEM_LOCK(vm); vm->vm_importfn = importfn; vm->vm_releasefn = releasefn; vm->vm_arg = arg; vm->vm_import_quantum = import_quantum; VMEM_UNLOCK(vm); } void vmem_set_limit(vmem_t *vm, vmem_size_t limit) { VMEM_LOCK(vm); vm->vm_limit = limit; VMEM_UNLOCK(vm); } void vmem_set_reclaim(vmem_t *vm, vmem_reclaim_t *reclaimfn) { VMEM_LOCK(vm); vm->vm_reclaimfn = reclaimfn; VMEM_UNLOCK(vm); } /* * vmem_init: Initializes vmem arena. */ vmem_t * vmem_init(vmem_t *vm, const char *name, vmem_addr_t base, vmem_size_t size, vmem_size_t quantum, vmem_size_t qcache_max, int flags) { int i; MPASS(quantum > 0); MPASS((quantum & (quantum - 1)) == 0); bzero(vm, sizeof(*vm)); VMEM_CONDVAR_INIT(vm, name); VMEM_LOCK_INIT(vm, name); vm->vm_nfreetags = 0; LIST_INIT(&vm->vm_freetags); strlcpy(vm->vm_name, name, sizeof(vm->vm_name)); vm->vm_quantum_mask = quantum - 1; vm->vm_quantum_shift = flsl(quantum) - 1; vm->vm_nbusytag = 0; vm->vm_size = 0; vm->vm_limit = 0; vm->vm_inuse = 0; qc_init(vm, qcache_max); TAILQ_INIT(&vm->vm_seglist); - for (i = 0; i < VMEM_MAXORDER; i++) { + vm->vm_cursor.bt_start = vm->vm_cursor.bt_size = 0; + vm->vm_cursor.bt_type = BT_TYPE_CURSOR; + TAILQ_INSERT_TAIL(&vm->vm_seglist, &vm->vm_cursor, bt_seglist); + + for (i = 0; i < VMEM_MAXORDER; i++) LIST_INIT(&vm->vm_freelist[i]); - } + memset(&vm->vm_hash0, 0, sizeof(vm->vm_hash0)); vm->vm_hashsize = VMEM_HASHSIZE_MIN; vm->vm_hashlist = vm->vm_hash0; if (size != 0) { if (vmem_add(vm, base, size, flags) != 0) { vmem_destroy1(vm); return NULL; } } mtx_lock(&vmem_list_lock); LIST_INSERT_HEAD(&vmem_list, vm, vm_alllist); mtx_unlock(&vmem_list_lock); return vm; } /* * vmem_create: create an arena. */ vmem_t * vmem_create(const char *name, vmem_addr_t base, vmem_size_t size, vmem_size_t quantum, vmem_size_t qcache_max, int flags) { vmem_t *vm; vm = uma_zalloc(vmem_zone, flags & (M_WAITOK|M_NOWAIT)); if (vm == NULL) return (NULL); if (vmem_init(vm, name, base, size, quantum, qcache_max, flags) == NULL) return (NULL); return (vm); } void vmem_destroy(vmem_t *vm) { mtx_lock(&vmem_list_lock); LIST_REMOVE(vm, vm_alllist); mtx_unlock(&vmem_list_lock); vmem_destroy1(vm); } vmem_size_t vmem_roundup_size(vmem_t *vm, vmem_size_t size) { return (size + vm->vm_quantum_mask) & ~vm->vm_quantum_mask; } /* * vmem_alloc: allocate resource from the arena. */ int vmem_alloc(vmem_t *vm, vmem_size_t size, int flags, vmem_addr_t *addrp) { const int strat __unused = flags & VMEM_FITMASK; qcache_t *qc; flags &= VMEM_FLAGS; MPASS(size > 0); - MPASS(strat == M_BESTFIT || strat == M_FIRSTFIT); + MPASS(strat == M_BESTFIT || strat == M_FIRSTFIT || strat == M_NEXTFIT); if ((flags & M_NOWAIT) == 0) WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "vmem_alloc"); if (size <= vm->vm_qcache_max) { /* * Resource 0 cannot be cached, so avoid a blocking allocation * in qc_import() and give the vmem_xalloc() call below a chance * to return 0. */ qc = &vm->vm_qcache[(size - 1) >> vm->vm_quantum_shift]; *addrp = (vmem_addr_t)uma_zalloc(qc->qc_cache, (flags & ~M_WAITOK) | M_NOWAIT); if (__predict_true(*addrp != 0)) return (0); } return (vmem_xalloc(vm, size, 0, 0, 0, VMEM_ADDR_MIN, VMEM_ADDR_MAX, flags, addrp)); } int vmem_xalloc(vmem_t *vm, const vmem_size_t size0, vmem_size_t align, const vmem_size_t phase, const vmem_size_t nocross, const vmem_addr_t minaddr, const vmem_addr_t maxaddr, int flags, vmem_addr_t *addrp) { const vmem_size_t size = vmem_roundup_size(vm, size0); struct vmem_freelist *list; struct vmem_freelist *first; struct vmem_freelist *end; - vmem_size_t avail; bt_t *bt; int error; int strat; flags &= VMEM_FLAGS; strat = flags & VMEM_FITMASK; MPASS(size0 > 0); MPASS(size > 0); - MPASS(strat == M_BESTFIT || strat == M_FIRSTFIT); + MPASS(strat == M_BESTFIT || strat == M_FIRSTFIT || strat == M_NEXTFIT); MPASS((flags & (M_NOWAIT|M_WAITOK)) != (M_NOWAIT|M_WAITOK)); if ((flags & M_NOWAIT) == 0) WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "vmem_xalloc"); MPASS((align & vm->vm_quantum_mask) == 0); MPASS((align & (align - 1)) == 0); MPASS((phase & vm->vm_quantum_mask) == 0); MPASS((nocross & vm->vm_quantum_mask) == 0); MPASS((nocross & (nocross - 1)) == 0); MPASS((align == 0 && phase == 0) || phase < align); MPASS(nocross == 0 || nocross >= size); MPASS(minaddr <= maxaddr); MPASS(!VMEM_CROSS_P(phase, phase + size - 1, nocross)); + if (strat == M_NEXTFIT) + MPASS(minaddr == VMEM_ADDR_MIN && maxaddr == VMEM_ADDR_MAX); if (align == 0) align = vm->vm_quantum_mask + 1; - *addrp = 0; + + /* + * Next-fit allocations don't use the freelists. + */ + if (strat == M_NEXTFIT) + return (vmem_xalloc_nextfit(vm, size0, align, phase, nocross, + flags, addrp)); + end = &vm->vm_freelist[VMEM_MAXORDER]; /* * choose a free block from which we allocate. */ first = bt_freehead_toalloc(vm, size, strat); VMEM_LOCK(vm); for (;;) { /* * Make sure we have enough tags to complete the * operation. */ if (vm->vm_nfreetags < BT_MAXALLOC && bt_fill(vm, flags) != 0) { error = ENOMEM; break; } + /* * Scan freelists looking for a tag that satisfies the * allocation. If we're doing BESTFIT we may encounter * sizes below the request. If we're doing FIRSTFIT we * inspect only the first element from each list. */ for (list = first; list < end; list++) { LIST_FOREACH(bt, list, bt_freelist) { if (bt->bt_size >= size) { error = vmem_fit(bt, size, align, phase, nocross, minaddr, maxaddr, addrp); if (error == 0) { vmem_clip(vm, bt, *addrp, size); goto out; } } /* FIRST skips to the next list. */ if (strat == M_FIRSTFIT) break; } } + /* * Retry if the fast algorithm failed. */ if (strat == M_FIRSTFIT) { strat = M_BESTFIT; first = bt_freehead_toalloc(vm, size, strat); continue; } - /* - * XXX it is possible to fail to meet restrictions with the - * imported region. It is up to the user to specify the - * import quantum such that it can satisfy any allocation. - */ - if (vmem_import(vm, size, align, flags) == 0) - continue; /* - * Try to free some space from the quantum cache or reclaim - * functions if available. + * Try a few measures to bring additional resources into the + * arena. If all else fails, we will sleep waiting for + * resources to be freed. */ - if (vm->vm_qcache_max != 0 || vm->vm_reclaimfn != NULL) { - avail = vm->vm_size - vm->vm_inuse; - VMEM_UNLOCK(vm); - if (vm->vm_qcache_max != 0) - qc_drain(vm); - if (vm->vm_reclaimfn != NULL) - vm->vm_reclaimfn(vm, flags); - VMEM_LOCK(vm); - /* If we were successful retry even NOWAIT. */ - if (vm->vm_size - vm->vm_inuse > avail) - continue; - } - if ((flags & M_NOWAIT) != 0) { + if (!vmem_try_fetch(vm, size, align, flags)) { error = ENOMEM; break; } - VMEM_CONDVAR_WAIT(vm); } out: VMEM_UNLOCK(vm); if (error != 0 && (flags & M_NOWAIT) == 0) panic("failed to allocate waiting allocation\n"); return (error); } /* * vmem_free: free the resource to the arena. */ void vmem_free(vmem_t *vm, vmem_addr_t addr, vmem_size_t size) { qcache_t *qc; MPASS(size > 0); if (size <= vm->vm_qcache_max && __predict_true(addr >= VMEM_ADDR_QCACHE_MIN)) { qc = &vm->vm_qcache[(size - 1) >> vm->vm_quantum_shift]; uma_zfree(qc->qc_cache, (void *)addr); } else vmem_xfree(vm, addr, size); } void vmem_xfree(vmem_t *vm, vmem_addr_t addr, vmem_size_t size) { bt_t *bt; bt_t *t; MPASS(size > 0); VMEM_LOCK(vm); bt = bt_lookupbusy(vm, addr); MPASS(bt != NULL); MPASS(bt->bt_start == addr); MPASS(bt->bt_size == vmem_roundup_size(vm, size) || bt->bt_size - vmem_roundup_size(vm, size) <= vm->vm_quantum_mask); MPASS(bt->bt_type == BT_TYPE_BUSY); bt_rembusy(vm, bt); bt->bt_type = BT_TYPE_FREE; /* coalesce */ t = TAILQ_NEXT(bt, bt_seglist); if (t != NULL && t->bt_type == BT_TYPE_FREE) { MPASS(BT_END(bt) < t->bt_start); /* YYY */ bt->bt_size += t->bt_size; bt_remfree(vm, t); bt_remseg(vm, t); } t = TAILQ_PREV(bt, vmem_seglist, bt_seglist); if (t != NULL && t->bt_type == BT_TYPE_FREE) { MPASS(BT_END(t) < bt->bt_start); /* YYY */ bt->bt_size += t->bt_size; bt->bt_start = t->bt_start; bt_remfree(vm, t); bt_remseg(vm, t); } - t = TAILQ_PREV(bt, vmem_seglist, bt_seglist); - MPASS(t != NULL); - MPASS(BT_ISSPAN_P(t) || t->bt_type == BT_TYPE_BUSY); - if (vm->vm_releasefn != NULL && t->bt_type == BT_TYPE_SPAN && - t->bt_size == bt->bt_size) { - vmem_addr_t spanaddr; - vmem_size_t spansize; - - MPASS(t->bt_start == bt->bt_start); - spanaddr = bt->bt_start; - spansize = bt->bt_size; - bt_remseg(vm, bt); - bt_remseg(vm, t); - vm->vm_size -= spansize; - VMEM_CONDVAR_BROADCAST(vm); - bt_freetrim(vm, BT_MAXFREE); - (*vm->vm_releasefn)(vm->vm_arg, spanaddr, spansize); - } else { + if (!vmem_try_release(vm, bt, false)) { bt_insfree(vm, bt); VMEM_CONDVAR_BROADCAST(vm); bt_freetrim(vm, BT_MAXFREE); } } /* * vmem_add: * */ int vmem_add(vmem_t *vm, vmem_addr_t addr, vmem_size_t size, int flags) { int error; error = 0; flags &= VMEM_FLAGS; VMEM_LOCK(vm); if (vm->vm_nfreetags >= BT_MAXALLOC || bt_fill(vm, flags) == 0) vmem_add1(vm, addr, size, BT_TYPE_SPAN_STATIC); else error = ENOMEM; VMEM_UNLOCK(vm); return (error); } /* * vmem_size: information about arenas size */ vmem_size_t vmem_size(vmem_t *vm, int typemask) { int i; switch (typemask) { case VMEM_ALLOC: return vm->vm_inuse; case VMEM_FREE: return vm->vm_size - vm->vm_inuse; case VMEM_FREE|VMEM_ALLOC: return vm->vm_size; case VMEM_MAXFREE: VMEM_LOCK(vm); for (i = VMEM_MAXORDER - 1; i >= 0; i--) { if (LIST_EMPTY(&vm->vm_freelist[i])) continue; VMEM_UNLOCK(vm); return ((vmem_size_t)ORDER2SIZE(i) << vm->vm_quantum_shift); } VMEM_UNLOCK(vm); return (0); default: panic("vmem_size"); } } /* ---- debug */ #if defined(DDB) || defined(DIAGNOSTIC) static void bt_dump(const bt_t *, int (*)(const char *, ...) __printflike(1, 2)); static const char * bt_type_string(int type) { switch (type) { case BT_TYPE_BUSY: return "busy"; case BT_TYPE_FREE: return "free"; case BT_TYPE_SPAN: return "span"; case BT_TYPE_SPAN_STATIC: return "static span"; + case BT_TYPE_CURSOR: + return "cursor"; default: break; } return "BOGUS"; } static void bt_dump(const bt_t *bt, int (*pr)(const char *, ...)) { (*pr)("\t%p: %jx %jx, %d(%s)\n", bt, (intmax_t)bt->bt_start, (intmax_t)bt->bt_size, bt->bt_type, bt_type_string(bt->bt_type)); } static void vmem_dump(const vmem_t *vm , int (*pr)(const char *, ...) __printflike(1, 2)) { const bt_t *bt; int i; (*pr)("vmem %p '%s'\n", vm, vm->vm_name); TAILQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) { bt_dump(bt, pr); } for (i = 0; i < VMEM_MAXORDER; i++) { const struct vmem_freelist *fl = &vm->vm_freelist[i]; if (LIST_EMPTY(fl)) { continue; } (*pr)("freelist[%d]\n", i); LIST_FOREACH(bt, fl, bt_freelist) { bt_dump(bt, pr); } } } #endif /* defined(DDB) || defined(DIAGNOSTIC) */ #if defined(DDB) #include static bt_t * vmem_whatis_lookup(vmem_t *vm, vmem_addr_t addr) { bt_t *bt; TAILQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) { if (BT_ISSPAN_P(bt)) { continue; } if (bt->bt_start <= addr && addr <= BT_END(bt)) { return bt; } } return NULL; } void vmem_whatis(vmem_addr_t addr, int (*pr)(const char *, ...)) { vmem_t *vm; LIST_FOREACH(vm, &vmem_list, vm_alllist) { bt_t *bt; bt = vmem_whatis_lookup(vm, addr); if (bt == NULL) { continue; } (*pr)("%p is %p+%zu in VMEM '%s' (%s)\n", (void *)addr, (void *)bt->bt_start, (vmem_size_t)(addr - bt->bt_start), vm->vm_name, (bt->bt_type == BT_TYPE_BUSY) ? "allocated" : "free"); } } void vmem_printall(const char *modif, int (*pr)(const char *, ...)) { const vmem_t *vm; LIST_FOREACH(vm, &vmem_list, vm_alllist) { vmem_dump(vm, pr); } } void vmem_print(vmem_addr_t addr, const char *modif, int (*pr)(const char *, ...)) { const vmem_t *vm = (const void *)addr; vmem_dump(vm, pr); } DB_SHOW_COMMAND(vmemdump, vmemdump) { if (!have_addr) { db_printf("usage: show vmemdump \n"); return; } vmem_dump((const vmem_t *)addr, db_printf); } DB_SHOW_ALL_COMMAND(vmemdump, vmemdumpall) { const vmem_t *vm; LIST_FOREACH(vm, &vmem_list, vm_alllist) vmem_dump(vm, db_printf); } DB_SHOW_COMMAND(vmem, vmem_summ) { const vmem_t *vm = (const void *)addr; const bt_t *bt; size_t ft[VMEM_MAXORDER], ut[VMEM_MAXORDER]; size_t fs[VMEM_MAXORDER], us[VMEM_MAXORDER]; int ord; if (!have_addr) { db_printf("usage: show vmem \n"); return; } db_printf("vmem %p '%s'\n", vm, vm->vm_name); db_printf("\tquantum:\t%zu\n", vm->vm_quantum_mask + 1); db_printf("\tsize:\t%zu\n", vm->vm_size); db_printf("\tinuse:\t%zu\n", vm->vm_inuse); db_printf("\tfree:\t%zu\n", vm->vm_size - vm->vm_inuse); db_printf("\tbusy tags:\t%d\n", vm->vm_nbusytag); db_printf("\tfree tags:\t%d\n", vm->vm_nfreetags); memset(&ft, 0, sizeof(ft)); memset(&ut, 0, sizeof(ut)); memset(&fs, 0, sizeof(fs)); memset(&us, 0, sizeof(us)); TAILQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) { ord = SIZE2ORDER(bt->bt_size >> vm->vm_quantum_shift); if (bt->bt_type == BT_TYPE_BUSY) { ut[ord]++; us[ord] += bt->bt_size; } else if (bt->bt_type == BT_TYPE_FREE) { ft[ord]++; fs[ord] += bt->bt_size; } } db_printf("\t\t\tinuse\tsize\t\tfree\tsize\n"); for (ord = 0; ord < VMEM_MAXORDER; ord++) { if (ut[ord] == 0 && ft[ord] == 0) continue; db_printf("\t%-15zu %zu\t%-15zu %zu\t%-16zu\n", ORDER2SIZE(ord) << vm->vm_quantum_shift, ut[ord], us[ord], ft[ord], fs[ord]); } } DB_SHOW_ALL_COMMAND(vmem, vmem_summall) { const vmem_t *vm; LIST_FOREACH(vm, &vmem_list, vm_alllist) vmem_summ((db_expr_t)vm, TRUE, count, modif); } #endif /* defined(DDB) */ #define vmem_printf printf #if defined(DIAGNOSTIC) static bool vmem_check_sanity(vmem_t *vm) { const bt_t *bt, *bt2; MPASS(vm != NULL); TAILQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) { if (bt->bt_start > BT_END(bt)) { printf("corrupted tag\n"); bt_dump(bt, vmem_printf); return false; } } TAILQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) { TAILQ_FOREACH(bt2, &vm->vm_seglist, bt_seglist) { if (bt == bt2) { continue; } if (BT_ISSPAN_P(bt) != BT_ISSPAN_P(bt2)) { continue; } if (bt->bt_start <= BT_END(bt2) && bt2->bt_start <= BT_END(bt)) { printf("overwrapped tags\n"); bt_dump(bt, vmem_printf); bt_dump(bt2, vmem_printf); return false; } } } return true; } static void vmem_check(vmem_t *vm) { if (!vmem_check_sanity(vm)) { panic("insanity vmem %p", vm); } } #endif /* defined(DIAGNOSTIC) */ Index: head/sys/sys/malloc.h =================================================================== --- head/sys/sys/malloc.h (revision 347948) +++ head/sys/sys/malloc.h (revision 347949) @@ -1,268 +1,269 @@ /*- * SPDX-License-Identifier: BSD-3-Clause * * Copyright (c) 1987, 1993 * The Regents of the University of California. * Copyright (c) 2005, 2009 Robert N. M. Watson * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)malloc.h 8.5 (Berkeley) 5/3/95 * $FreeBSD$ */ #ifndef _SYS_MALLOC_H_ #define _SYS_MALLOC_H_ #include #ifdef _KERNEL #include #endif #include #include #include #include #define MINALLOCSIZE UMA_SMALLEST_UNIT /* * Flags to memory allocation functions. */ #define M_NOWAIT 0x0001 /* do not block */ #define M_WAITOK 0x0002 /* ok to block */ #define M_ZERO 0x0100 /* bzero the allocation */ #define M_NOVM 0x0200 /* don't ask VM for pages */ #define M_USE_RESERVE 0x0400 /* can alloc out of reserve memory */ #define M_NODUMP 0x0800 /* don't dump pages in this allocation */ -#define M_FIRSTFIT 0x1000 /* Only for vmem, fast fit. */ -#define M_BESTFIT 0x2000 /* Only for vmem, low fragmentation. */ -#define M_EXEC 0x4000 /* allocate executable space. */ +#define M_FIRSTFIT 0x1000 /* only for vmem, fast fit */ +#define M_BESTFIT 0x2000 /* only for vmem, low fragmentation */ +#define M_EXEC 0x4000 /* allocate executable space */ +#define M_NEXTFIT 0x8000 /* only for vmem, follow cursor */ #define M_MAGIC 877983977 /* time when first defined :-) */ /* * Two malloc type structures are present: malloc_type, which is used by a * type owner to declare the type, and malloc_type_internal, which holds * malloc-owned statistics and other ABI-sensitive fields, such as the set of * malloc statistics indexed by the compile-time MAXCPU constant. * Applications should avoid introducing dependence on the allocator private * data layout and size. * * The malloc_type ks_next field is protected by malloc_mtx. Other fields in * malloc_type are static after initialization so unsynchronized. * * Statistics in malloc_type_stats are written only when holding a critical * section and running on the CPU associated with the index into the stat * array, but read lock-free resulting in possible (minor) races, which the * monitoring app should take into account. */ struct malloc_type_stats { uint64_t mts_memalloced; /* Bytes allocated on CPU. */ uint64_t mts_memfreed; /* Bytes freed on CPU. */ uint64_t mts_numallocs; /* Number of allocates on CPU. */ uint64_t mts_numfrees; /* number of frees on CPU. */ uint64_t mts_size; /* Bitmask of sizes allocated on CPU. */ uint64_t _mts_reserved1; /* Reserved field. */ uint64_t _mts_reserved2; /* Reserved field. */ uint64_t _mts_reserved3; /* Reserved field. */ }; /* * Index definitions for the mti_probes[] array. */ #define DTMALLOC_PROBE_MALLOC 0 #define DTMALLOC_PROBE_FREE 1 #define DTMALLOC_PROBE_MAX 2 struct malloc_type_internal { uint32_t mti_probes[DTMALLOC_PROBE_MAX]; /* DTrace probe ID array. */ u_char mti_zone; struct malloc_type_stats *mti_stats; }; /* * Public data structure describing a malloc type. Private data is hung off * of ks_handle to avoid encoding internal malloc(9) data structures in * modules, which will statically allocate struct malloc_type. */ struct malloc_type { struct malloc_type *ks_next; /* Next in global chain. */ u_long ks_magic; /* Detect programmer error. */ const char *ks_shortdesc; /* Printable type name. */ void *ks_handle; /* Priv. data, was lo_class. */ }; /* * Statistics structure headers for user space. The kern.malloc sysctl * exposes a structure stream consisting of a stream header, then a series of * malloc type headers and statistics structures (quantity maxcpus). For * convenience, the kernel will provide the current value of maxcpus at the * head of the stream. */ #define MALLOC_TYPE_STREAM_VERSION 0x00000001 struct malloc_type_stream_header { uint32_t mtsh_version; /* Stream format version. */ uint32_t mtsh_maxcpus; /* Value of MAXCPU for stream. */ uint32_t mtsh_count; /* Number of records. */ uint32_t _mtsh_pad; /* Pad/reserved field. */ }; #define MALLOC_MAX_NAME 32 struct malloc_type_header { char mth_name[MALLOC_MAX_NAME]; }; #ifdef _KERNEL #define MALLOC_DEFINE(type, shortdesc, longdesc) \ struct malloc_type type[1] = { \ { NULL, M_MAGIC, shortdesc, NULL } \ }; \ SYSINIT(type##_init, SI_SUB_KMEM, SI_ORDER_THIRD, malloc_init, \ type); \ SYSUNINIT(type##_uninit, SI_SUB_KMEM, SI_ORDER_ANY, \ malloc_uninit, type) #define MALLOC_DECLARE(type) \ extern struct malloc_type type[1] MALLOC_DECLARE(M_CACHE); MALLOC_DECLARE(M_DEVBUF); MALLOC_DECLARE(M_TEMP); /* * XXX this should be declared in , but that tends to fail * because is included in a header before the source file * has a chance to include to get MALLOC_DECLARE() defined. */ MALLOC_DECLARE(M_IOV); struct domainset; extern struct mtx malloc_mtx; /* * Function type used when iterating over the list of malloc types. */ typedef void malloc_type_list_func_t(struct malloc_type *, void *); void contigfree(void *addr, unsigned long size, struct malloc_type *type); void *contigmalloc(unsigned long size, struct malloc_type *type, int flags, vm_paddr_t low, vm_paddr_t high, unsigned long alignment, vm_paddr_t boundary) __malloc_like __result_use_check __alloc_size(1) __alloc_align(6); void *contigmalloc_domainset(unsigned long size, struct malloc_type *type, struct domainset *ds, int flags, vm_paddr_t low, vm_paddr_t high, unsigned long alignment, vm_paddr_t boundary) __malloc_like __result_use_check __alloc_size(1) __alloc_align(6); void free(void *addr, struct malloc_type *type); void free_domain(void *addr, struct malloc_type *type); void *malloc(size_t size, struct malloc_type *type, int flags) __malloc_like __result_use_check __alloc_size(1); /* * Try to optimize malloc(..., ..., M_ZERO) allocations by doing zeroing in * place if the size is known at compilation time. * * Passing the flag down requires malloc to blindly zero the entire object. * In practice a lot of the zeroing can be avoided if most of the object * gets explicitly initialized after the allocation. Letting the compiler * zero in place gives it the opportunity to take advantage of this state. * * Note that the operation is only applicable if both flags and size are * known at compilation time. If M_ZERO is passed but M_WAITOK is not, the * allocation can fail and a NULL check is needed. However, if M_WAITOK is * passed we know the allocation must succeed and the check can be elided. * * _malloc_item = malloc(_size, type, (flags) &~ M_ZERO); * if (((flags) & M_WAITOK) != 0 || _malloc_item != NULL) * bzero(_malloc_item, _size); * * If the flag is set, the compiler knows the left side is always true, * therefore the entire statement is true and the callsite is: * * _malloc_item = malloc(_size, type, (flags) &~ M_ZERO); * bzero(_malloc_item, _size); * * If the flag is not set, the compiler knows the left size is always false * and the NULL check is needed, therefore the callsite is: * * _malloc_item = malloc(_size, type, (flags) &~ M_ZERO); * if (_malloc_item != NULL) * bzero(_malloc_item, _size); * * The implementation is a macro because of what appears to be a clang 6 bug: * an inline function variant ended up being compiled to a mere malloc call * regardless of argument. gcc generates expected code (like the above). */ #define malloc(size, type, flags) ({ \ void *_malloc_item; \ size_t _size = (size); \ if (__builtin_constant_p(size) && __builtin_constant_p(flags) &&\ ((flags) & M_ZERO) != 0) { \ _malloc_item = malloc(_size, type, (flags) &~ M_ZERO); \ if (((flags) & M_WAITOK) != 0 || \ __predict_true(_malloc_item != NULL)) \ bzero(_malloc_item, _size); \ } else { \ _malloc_item = malloc(_size, type, flags); \ } \ _malloc_item; \ }) void *malloc_domainset(size_t size, struct malloc_type *type, struct domainset *ds, int flags) __malloc_like __result_use_check __alloc_size(1); void *mallocarray(size_t nmemb, size_t size, struct malloc_type *type, int flags) __malloc_like __result_use_check __alloc_size2(1, 2); void malloc_init(void *); int malloc_last_fail(void); void malloc_type_allocated(struct malloc_type *type, unsigned long size); void malloc_type_freed(struct malloc_type *type, unsigned long size); void malloc_type_list(malloc_type_list_func_t *, void *); void malloc_uninit(void *); void *realloc(void *addr, size_t size, struct malloc_type *type, int flags) __result_use_check __alloc_size(2); void *reallocf(void *addr, size_t size, struct malloc_type *type, int flags) __result_use_check __alloc_size(2); struct malloc_type *malloc_desc2type(const char *desc); /* * This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX * if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW */ #define MUL_NO_OVERFLOW (1UL << (sizeof(size_t) * 8 / 2)) static inline bool WOULD_OVERFLOW(size_t nmemb, size_t size) { return ((nmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) && nmemb > 0 && __SIZE_T_MAX / nmemb < size); } #undef MUL_NO_OVERFLOW #endif /* _KERNEL */ #endif /* !_SYS_MALLOC_H_ */