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Index: sys/sys/malloc.h
===================================================================
--- sys/sys/malloc.h
+++ sys/sys/malloc.h
@@ -53,6 +53,7 @@
*/
#define M_NOWAIT 0x0001 /* do not block */
#define M_WAITOK 0x0002 /* ok to block */
+#define M_STABLE 0x0004 /* memory is unlikely to be reused */
#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 */
Index: sys/vm/uma_core.c
===================================================================
--- sys/vm/uma_core.c
+++ sys/vm/uma_core.c
@@ -1506,7 +1506,6 @@
int aflags)
{
uma_domain_t dom;
- uma_alloc allocf;
uma_slab_t slab;
unsigned long size;
uint8_t *mem;
@@ -1516,7 +1515,6 @@
KASSERT(domain >= 0 && domain < vm_ndomains,
("keg_alloc_slab: domain %d out of range", domain));
- allocf = keg->uk_allocf;
slab = NULL;
mem = NULL;
if (keg->uk_flags & UMA_ZFLAG_OFFPAGE) {
@@ -1540,12 +1538,14 @@
else
aflags &= ~M_ZERO;
- if (keg->uk_flags & UMA_ZONE_NODUMP)
+ if ((keg->uk_flags & UMA_ZONE_NODUMP) != 0)
aflags |= M_NODUMP;
+ if ((keg->uk_flags & UMA_ZONE_NOFREE) != 0)
+ aflags |= M_STABLE;
/* zone is passed for legacy reasons. */
size = keg->uk_ppera * PAGE_SIZE;
- mem = allocf(zone, size, domain, &sflags, aflags);
+ mem = keg->uk_allocf(zone, size, domain, &sflags, aflags);
if (mem == NULL) {
if (keg->uk_flags & UMA_ZFLAG_OFFPAGE)
zone_free_item(slabzone(keg->uk_ipers),
@@ -1673,26 +1673,14 @@
}
}
-/*
- * Allocates a number of pages from the system
- *
- * Arguments:
- * bytes The number of bytes requested
- * wait Shall we wait?
- *
- * Returns:
- * A pointer to the alloced memory or possibly
- * NULL if M_NOWAIT is set.
- */
static void *
page_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *pflag,
- int wait)
+ int flags)
{
- void *p; /* Returned page */
+ void *p;
*pflag = UMA_SLAB_KERNEL;
- p = (void *)kmem_malloc_domainset(DOMAINSET_FIXED(domain), bytes, wait);
-
+ p = (void *)kmem_malloc_domainset(DOMAINSET_FIXED(domain), bytes, flags);
return (p);
}
@@ -1817,12 +1805,12 @@
*/
static void *
contig_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *pflag,
- int wait)
+ int flags)
{
*pflag = UMA_SLAB_KERNEL;
return ((void *)kmem_alloc_contig_domainset(DOMAINSET_FIXED(domain),
- bytes, wait, 0, ~(vm_paddr_t)0, 1, 0, VM_MEMATTR_DEFAULT));
+ bytes, flags, 0, ~(vm_paddr_t)0, 1, 0, VM_MEMATTR_DEFAULT));
}
/*
@@ -2249,7 +2237,7 @@
* startup cache until the vm is ready.
*/
#ifdef UMA_MD_SMALL_ALLOC
- if (keg->uk_ppera == 1)
+ if (keg->uk_ppera == 1 && (keg->uk_flags & UMA_ZONE_NOFREE) == 0)
keg->uk_allocf = uma_small_alloc;
else
#endif
Index: sys/vm/vm_kern.c
===================================================================
--- sys/vm/vm_kern.c
+++ sys/vm/vm_kern.c
@@ -121,6 +121,15 @@
#endif
"Max kernel address");
+static SYSCTL_NODE(_vm_stats, OID_AUTO, kern, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
+ "Kernel memory statistics");
+
+static counter_u64_t nofree_import_failures = EARLY_COUNTER;
+COUNTER_U64_SYSINIT(nofree_import_failures);
+SYSCTL_COUNTER_U64(_vm_stats_kern, OID_AUTO, nofree_import_failures,
+ CTLFLAG_RD, &nofree_import_failures,
+ "Number of failed M_STABLE imports");
+
#if VM_NRESERVLEVEL > 0
#define KVA_QUANTUM_SHIFT (VM_LEVEL_0_ORDER + PAGE_SHIFT)
#else
@@ -169,6 +178,30 @@
vmem_free(kernel_arena, addr, size);
}
+#if VM_NRESERVLEVEL > 0
+/*
+ * Allocate kernel memory to satisfy a M_STABLE request, meaning that the
+ * memory is expected never to be freed. Such allocations are physically
+ * contiguous so as to minimize fragmentation.
+ */
+static vm_offset_t
+kmem_alloc_nofree(int domain, vm_size_t size, u_long align, int flags)
+{
+ vm_offset_t addr;
+
+ KASSERT(size + align <= KVA_QUANTUM,
+ ("%s: unhandled size %#lx and alignment %#lx",
+ __func__, size, align));
+
+ if (vmem_xalloc(vm_dom[domain].vmd_kernel_nofree_arena, size, align,
+ 0, 0, VMEM_ADDR_MIN, VMEM_ADDR_MAX, flags | M_BESTFIT, &addr) != 0)
+ return (0);
+ if ((flags & M_ZERO) != 0)
+ memset((void *)addr, 0, size);
+ return (addr);
+}
+#endif
+
/*
* Allocates a region from the kernel address map and physical pages
* within the specified address range to the kernel object. Creates a
@@ -188,6 +221,9 @@
int pflags, tries;
vm_prot_t prot;
+ KASSERT((flags & M_STABLE) == 0,
+ ("%s: does not handle M_STABLE allocations", __func__));
+
size = round_page(size);
vmem = vm_dom[domain].vmd_kernel_arena;
if (vmem_alloc(vmem, size, M_BESTFIT | flags, &addr))
@@ -273,13 +309,24 @@
vm_memattr_t memattr)
{
vmem_t *vmem;
- vm_object_t object = kernel_object;
+ vm_object_t object;
vm_offset_t addr, offset, tmp;
vm_page_t end_m, m;
u_long npages;
int pflags, tries;
size = round_page(size);
+ if ((flags & M_STABLE) != 0) {
+ flags &= ~M_STABLE;
+#if VM_NRESERVLEVEL > 0
+ if (low == 0 && high == ~(vm_paddr_t)0 && boundary == 0) {
+ addr = kmem_alloc_nofree(domain, size, alignment,
+ flags);
+ if (addr != 0)
+ return (addr);
+ }
+#endif
+ }
vmem = vm_dom[domain].vmd_kernel_arena;
if (vmem_alloc(vmem, size, flags | M_BESTFIT, &addr))
return (0);
@@ -288,6 +335,7 @@
pflags &= ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL);
pflags |= VM_ALLOC_NOWAIT;
npages = atop(size);
+ object = kernel_object;
VM_OBJECT_WLOCK(object);
tries = 0;
retry:
@@ -402,15 +450,20 @@
vm_offset_t addr;
int rv;
-#if VM_NRESERVLEVEL > 0
- if (__predict_true((flags & M_EXEC) == 0))
+ size = round_page(size);
+ if (__predict_true((flags & (M_EXEC | M_STABLE)) == 0))
arena = vm_dom[domain].vmd_kernel_arena;
- else
+ else if ((flags & M_EXEC) != 0)
arena = vm_dom[domain].vmd_kernel_rwx_arena;
-#else
- arena = vm_dom[domain].vmd_kernel_arena;
+ else {
+ flags &= ~M_STABLE;
+#if VM_NRESERVLEVEL > 0
+ addr = kmem_alloc_nofree(domain, size, PAGE_SIZE, flags);
+ if (addr != 0)
+ return (addr);
#endif
- size = round_page(size);
+ arena = vm_dom[domain].vmd_kernel_arena;
+ }
if (vmem_alloc(arena, size, flags | M_BESTFIT, &addr))
return (0);
@@ -462,7 +515,9 @@
int pflags;
KASSERT(object == kernel_object,
- ("kmem_back_domain: only supports kernel object."));
+ ("%s: only supports kernel object", __func__));
+ KASSERT((flags & M_STABLE) == 0,
+ ("%s: does not handle M_STABLE allocations", __func__));
offset = addr - VM_MIN_KERNEL_ADDRESS;
pflags = malloc2vm_flags(flags) | VM_ALLOC_WIRED;
@@ -501,10 +556,8 @@
vm_page_valid(m);
pmap_enter(kernel_pmap, addr + i, m, prot,
prot | PMAP_ENTER_WIRED, 0);
-#if VM_NRESERVLEVEL > 0
if (__predict_false((prot & VM_PROT_EXECUTE) != 0))
m->oflags |= VPO_KMEM_EXEC;
-#endif
}
VM_OBJECT_WUNLOCK(object);
@@ -578,14 +631,10 @@
VM_OBJECT_WLOCK(object);
m = vm_page_lookup(object, atop(offset));
domain = vm_phys_domain(m);
-#if VM_NRESERVLEVEL > 0
if (__predict_true((m->oflags & VPO_KMEM_EXEC) == 0))
arena = vm_dom[domain].vmd_kernel_arena;
else
arena = vm_dom[domain].vmd_kernel_rwx_arena;
-#else
- arena = vm_dom[domain].vmd_kernel_arena;
-#endif
for (; offset < end; offset += PAGE_SIZE, m = next) {
next = vm_page_next(m);
vm_page_xbusy_claim(m);
@@ -736,12 +785,37 @@
{
KASSERT((size % KVA_QUANTUM) == 0,
- ("kva_import_domain: Size %jd is not a multiple of %d",
+ ("%s: Size %jd is not a multiple of %d", __func__,
(intmax_t)size, (int)KVA_QUANTUM));
return (vmem_xalloc(arena, size, KVA_QUANTUM, 0, 0, VMEM_ADDR_MIN,
VMEM_ADDR_MAX, flags, addrp));
}
+#if VM_NRESERVLEVEL > 0
+static int
+kva_import_nofree(void *arg, vmem_size_t size, int flags, vmem_addr_t *addrp)
+{
+ int domain;
+
+ domain = (int)(uintptr_t)arg;
+ KASSERT(domain >= 0 && domain < vm_ndomains,
+ ("%s: Invalid domain index %d", __func__, domain));
+ KASSERT((size % KVA_QUANTUM) == 0,
+ ("%s: Size %jd is not a multiple of %d", __func__,
+ (intmax_t)size, (int)KVA_QUANTUM));
+
+ /* XXX this does not necessarily give suitably aligned KVA */
+ *addrp = (vmem_addr_t)kmem_alloc_contig_domain(domain, size, flags,
+ 0, ~(vm_paddr_t)0, KVA_QUANTUM, 0, VM_MEMATTR_DEFAULT);
+ if (*addrp == 0) {
+ counter_u64_add(nofree_import_failures, 1);
+ return (ENOMEM);
+ } else {
+ return (0);
+ }
+}
+#endif
+
/*
* kmem_init:
*
@@ -804,9 +878,13 @@
/*
* In architectures with superpages, maintain separate arenas
- * for allocations with permissions that differ from the
- * "standard" read/write permissions used for kernel memory,
- * so as not to inhibit superpage promotion.
+ * for
+ * 1) allocations with permissions that differ from the
+ * "standard" read/write permissions used for kernel memory,
+ * and
+ * 2) allocations which are never going to be freed.
+ *
+ * This helps minimize fragmentation of physical memory.
*/
#if VM_NRESERVLEVEL > 0
vm_dom[domain].vmd_kernel_rwx_arena = vmem_create(
@@ -814,6 +892,14 @@
vmem_set_import(vm_dom[domain].vmd_kernel_rwx_arena,
kva_import_domain, (vmem_release_t *)vmem_xfree,
kernel_arena, KVA_QUANTUM);
+ vm_dom[domain].vmd_kernel_nofree_arena = vmem_create(
+ "kernel nofree arena domain", 0, 0, PAGE_SIZE, 0, M_WAITOK);
+ vmem_set_import(vm_dom[domain].vmd_kernel_nofree_arena,
+ kva_import_nofree, (vmem_release_t *)vmem_xfree,
+ (void *)(uintptr_t)domain, KVA_QUANTUM);
+#else
+ vm_dom[domain].vmd_kernel_rwx_arena = kernel_arena;
+ vm_dom[domain].vmd_kernel_nofree_arena = kernel_arena;
#endif
}
Index: sys/vm/vm_pagequeue.h
===================================================================
--- sys/vm/vm_pagequeue.h
+++ sys/vm/vm_pagequeue.h
@@ -242,8 +242,9 @@
int pool;
uma_zone_t zone;
} vmd_pgcache[VM_NFREEPOOL];
- struct vmem *vmd_kernel_arena; /* (c) per-domain kva R/W arena. */
- struct vmem *vmd_kernel_rwx_arena; /* (c) per-domain kva R/W/X arena. */
+ struct vmem *vmd_kernel_arena; /* (c) per-domain KVA */
+ struct vmem *vmd_kernel_rwx_arena; /* (c) per-domain RWX KVA */
+ struct vmem *vmd_kernel_nofree_arena; /* (c) per-domain nofree KVA */
u_int vmd_domain; /* (c) Domain number. */
u_int vmd_page_count; /* (c) Total page count. */
long vmd_segs; /* (c) bitmask of the segments */

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