Index: sys/conf/options =================================================================== --- sys/conf/options +++ sys/conf/options @@ -712,6 +712,8 @@ WITNESS_COUNT opt_witness.h OPENSOLARIS_WITNESS opt_global.h +EPOCH_TRACE opt_epoch.h + # options for ACPI support ACPI_DEBUG opt_acpi.h ACPI_MAX_TASKS opt_acpi.h Index: sys/kern/kern_thread.c =================================================================== --- sys/kern/kern_thread.c +++ sys/kern/kern_thread.c @@ -668,6 +668,7 @@ LIST_INIT(&td->td_contested); LIST_INIT(&td->td_lprof[0]); LIST_INIT(&td->td_lprof[1]); + SLIST_INIT(&td->td_epochs); sigqueue_init(&td->td_sigqueue, p); callout_init(&td->td_slpcallout, 1); TAILQ_INSERT_TAIL(&p->p_threads, td, td_plist); @@ -684,6 +685,8 @@ struct proc *p = td->td_proc; PROC_LOCK_ASSERT(p, MA_OWNED); + MPASS(SLIST_EMPTY(&td->td_epochs)); + TAILQ_REMOVE(&p->p_threads, td, td_plist); p->p_numthreads--; /* could clear a few other things here */ Index: sys/kern/subr_epoch.c =================================================================== --- sys/kern/subr_epoch.c +++ sys/kern/subr_epoch.c @@ -30,7 +30,6 @@ __FBSDID("$FreeBSD$"); #include -#include #include #include #include @@ -47,6 +46,11 @@ #include #include #include +#ifdef EPOCH_TRACE +#include +#include +#include +#endif #include #include #include @@ -80,6 +84,7 @@ struct sx e_drain_sx; struct mtx e_drain_mtx; volatile int e_drain_count; + const char *e_name; }; /* arbitrary --- needs benchmarking */ @@ -134,6 +139,103 @@ static void epoch_call_task(void *context __unused); static uma_zone_t pcpu_zone_record; +#ifdef EPOCH_TRACE +struct stackentry { + RB_ENTRY(stackentry) se_node; + struct stack se_stack; +}; + +static int +stackentry_compare(struct stackentry *a, struct stackentry *b) +{ + + if (a->se_stack.depth > b->se_stack.depth) + return (1); + if (a->se_stack.depth < b->se_stack.depth) + return (-1); + for (int i = 0; i < a->se_stack.depth; i++) { + if (a->se_stack.pcs[i] > b->se_stack.pcs[i]) + return (1); + if (a->se_stack.pcs[i] < b->se_stack.pcs[i]) + return (-1); + } + + return (0); +} + +RB_HEAD(stacktree, stackentry) epoch_stacks = RB_INITIALIZER(&epoch_stacks); +RB_GENERATE_STATIC(stacktree, stackentry, se_node, stackentry_compare); + +static struct mtx epoch_stacks_lock; +MTX_SYSINIT(epochstacks, &epoch_stacks_lock, "epoch_stacks", MTX_DEF); + +static void epoch_trace_report(const char *fmt, ...) __printflike(1, 2); +static inline void +epoch_trace_report(const char *fmt, ...) +{ + va_list ap; + struct stackentry se, *new; + + stack_zero(&se.se_stack); /* XXX: is it really needed? */ + stack_save(&se.se_stack); + + /* Tree is never reduced - go lockless. */ + if (RB_FIND(stacktree, &epoch_stacks, &se) != NULL) + return; + + new = malloc(sizeof(*new), M_STACK, M_NOWAIT); + if (new != NULL) { + bcopy(&se.se_stack, &new->se_stack, sizeof(struct stack)); + + mtx_lock(&epoch_stacks_lock); + new = RB_INSERT(stacktree, &epoch_stacks, new); + mtx_unlock(&epoch_stacks_lock); + if (new != NULL) + free(new, M_STACK); + } + + va_start(ap, fmt); + (void)vprintf(fmt, ap); + va_end(ap); + stack_print_ddb(&se.se_stack); +} + +static inline void +epoch_trace_enter(struct thread *td, epoch_t epoch, epoch_tracker_t et, + const char *file, int line) +{ + epoch_tracker_t iet; + + SLIST_FOREACH(iet, &td->td_epochs, et_tlink) + if (iet->et_epoch == epoch) + epoch_trace_report("Recursively entering epoch %s " + "previously entered at %s:%d\n", + epoch->e_name, iet->et_file, iet->et_line); + et->et_epoch = epoch; + et->et_file = file; + et->et_line = line; + SLIST_INSERT_HEAD(&td->td_epochs, et, et_tlink); +} + +static inline void +epoch_trace_exit(struct thread *td, epoch_t epoch, epoch_tracker_t et, + const char *file, int line) +{ + + if (SLIST_FIRST(&td->td_epochs) != et) { + epoch_trace_report("Exiting epoch %s in a not nested order. " + "Most recently entered %s at %s:%d\n", + epoch->e_name, + SLIST_FIRST(&td->td_epochs)->et_epoch->e_name, + SLIST_FIRST(&td->td_epochs)->et_file, + SLIST_FIRST(&td->td_epochs)->et_line); + /* This will panic if et is not anywhere on td_epochs. */ + SLIST_REMOVE(&td->td_epochs, et, epoch_tracker, et_tlink); + } else + SLIST_REMOVE_HEAD(&td->td_epochs, et_tlink); +} +#endif /* EPOCH_TRACE */ + static void epoch_init(void *arg __unused) { @@ -156,9 +258,10 @@ DPCPU_ID_PTR(cpu, epoch_cb_task), NULL, cpu, NULL, NULL, "epoch call task"); } + SLIST_INIT(&thread0.td_epochs); inited = 1; - global_epoch = epoch_alloc(0); - global_epoch_preempt = epoch_alloc(EPOCH_PREEMPT); + global_epoch = epoch_alloc("Global", 0); + global_epoch_preempt = epoch_alloc("Global preemptible", EPOCH_PREEMPT); } SYSINIT(epoch, SI_SUB_TASKQ + 1, SI_ORDER_FIRST, epoch_init, NULL); @@ -198,7 +301,7 @@ } epoch_t -epoch_alloc(int flags) +epoch_alloc(const char *name, int flags) { epoch_t epoch; @@ -210,6 +313,7 @@ MPASS(epoch_count < MAX_EPOCHS - 2); epoch->e_flags = flags; epoch->e_idx = epoch_count; + epoch->e_name = name; sx_init(&epoch->e_drain_sx, "epoch-drain-sx"); mtx_init(&epoch->e_drain_mtx, "epoch-drain-mtx", NULL, MTX_DEF); allepochs[epoch_count++] = epoch; @@ -243,7 +347,7 @@ } while (0) void -epoch_enter_preempt(epoch_t epoch, epoch_tracker_t et) +_epoch_enter_preempt(epoch_t epoch, epoch_tracker_t et EPOCH_FILE_LINE) { struct epoch_record *er; struct thread *td; @@ -251,16 +355,14 @@ MPASS(cold || epoch != NULL); INIT_CHECK(epoch); MPASS(epoch->e_flags & EPOCH_PREEMPT); -#ifdef EPOCH_TRACKER_DEBUG - et->et_magic_pre = EPOCH_MAGIC0; - et->et_magic_post = EPOCH_MAGIC1; -#endif td = curthread; +#ifdef EPOCH_TRACE + epoch_trace_enter(td, epoch, et, file, line); +#endif et->et_td = td; td->td_epochnest++; critical_enter(); sched_pin(); - td->td_pre_epoch_prio = td->td_priority; er = epoch_currecord(epoch); TAILQ_INSERT_TAIL(&er->er_tdlist, et, et_link); @@ -277,7 +379,6 @@ MPASS(cold || epoch != NULL); INIT_CHECK(epoch); td = curthread; - td->td_epochnest++; critical_enter(); er = epoch_currecord(epoch); @@ -285,7 +386,7 @@ } void -epoch_exit_preempt(epoch_t epoch, epoch_tracker_t et) +_epoch_exit_preempt(epoch_t epoch, epoch_tracker_t et EPOCH_FILE_LINE) { struct epoch_record *er; struct thread *td; @@ -300,12 +401,6 @@ MPASS(epoch->e_flags & EPOCH_PREEMPT); MPASS(et != NULL); MPASS(et->et_td == td); -#ifdef EPOCH_TRACKER_DEBUG - MPASS(et->et_magic_pre == EPOCH_MAGIC0); - MPASS(et->et_magic_post == EPOCH_MAGIC1); - et->et_magic_pre = 0; - et->et_magic_post = 0; -#endif #ifdef INVARIANTS et->et_td = (void*)0xDEADBEEF; #endif @@ -315,6 +410,9 @@ if (__predict_false(td->td_pre_epoch_prio != td->td_priority)) epoch_adjust_prio(td, td->td_pre_epoch_prio); critical_exit(); +#ifdef EPOCH_TRACE + epoch_trace_exit(td, epoch, et, file, line); +#endif } void Index: sys/kern/subr_stack.c =================================================================== --- sys/kern/subr_stack.c +++ sys/kern/subr_stack.c @@ -45,7 +45,7 @@ FEATURE(stack, "Support for capturing kernel stack"); -static MALLOC_DEFINE(M_STACK, "stack", "Stack Traces"); +MALLOC_DEFINE(M_STACK, "stack", "Stack Traces"); static int stack_symbol(vm_offset_t pc, char *namebuf, u_int buflen, long *offset, int flags); Index: sys/net/if.c =================================================================== --- sys/net/if.c +++ sys/net/if.c @@ -940,8 +940,8 @@ if_epochalloc(void *dummy __unused) { - net_epoch_preempt = epoch_alloc(EPOCH_PREEMPT); - net_epoch = epoch_alloc(0); + net_epoch_preempt = epoch_alloc("Net preemptible", EPOCH_PREEMPT); + net_epoch = epoch_alloc("Net", 0); } SYSINIT(ifepochalloc, SI_SUB_TASKQ + 1, SI_ORDER_ANY, if_epochalloc, NULL); Index: sys/sys/epoch.h =================================================================== --- sys/sys/epoch.h +++ sys/sys/epoch.h @@ -41,6 +41,8 @@ #include #include +#include "opt_epoch.h" + struct epoch; typedef struct epoch *epoch_t; @@ -51,21 +53,19 @@ extern epoch_t global_epoch_preempt; struct epoch_tracker { -#ifdef EPOCH_TRACKER_DEBUG -#define EPOCH_MAGIC0 0xFADECAFEF00DD00D -#define EPOCH_MAGIC1 0xBADDBABEDEEDFEED - uint64_t et_magic_pre; -#endif TAILQ_ENTRY(epoch_tracker) et_link; struct thread *et_td; ck_epoch_section_t et_section; -#ifdef EPOCH_TRACKER_DEBUG - uint64_t et_magic_post; +#ifdef EPOCH_TRACE + struct epoch *et_epoch; + SLIST_ENTRY(epoch_tracker) et_tlink; + const char *et_file; + int et_line; #endif } __aligned(sizeof(void *)); typedef struct epoch_tracker *epoch_tracker_t; -epoch_t epoch_alloc(int flags); +epoch_t epoch_alloc(const char *name, int flags); void epoch_free(epoch_t epoch); void epoch_wait(epoch_t epoch); void epoch_wait_preempt(epoch_t epoch); @@ -75,11 +75,22 @@ int in_epoch_verbose(epoch_t epoch, int dump_onfail); DPCPU_DECLARE(int, epoch_cb_count); DPCPU_DECLARE(struct grouptask, epoch_cb_task); -#define EPOCH_MAGIC0 0xFADECAFEF00DD00D -#define EPOCH_MAGIC1 0xBADDBABEDEEDFEED -void epoch_enter_preempt(epoch_t epoch, epoch_tracker_t et); -void epoch_exit_preempt(epoch_t epoch, epoch_tracker_t et); +#ifdef EPOCH_TRACE +#define EPOCH_FILE_LINE , const char *file, int line +#else +#define EPOCH_FILE_LINE +#endif + +void _epoch_enter_preempt(epoch_t epoch, epoch_tracker_t et EPOCH_FILE_LINE); +void _epoch_exit_preempt(epoch_t epoch, epoch_tracker_t et EPOCH_FILE_LINE); +#ifdef EPOCH_TRACE +#define epoch_enter_preempt(epoch, et) _epoch_enter_preempt(epoch, et, __FILE__, __LINE__) +#define epoch_exit_preempt(epoch, et) _epoch_exit_preempt(epoch, et, __FILE__, __LINE__) +#else +#define epoch_enter_preempt(epoch, et) _epoch_enter_preempt(epoch, et) +#define epoch_exit_preempt(epoch, et) _epoch_exit_preempt(epoch, et) +#endif void epoch_enter(epoch_t epoch); void epoch_exit(epoch_t epoch); Index: sys/sys/proc.h =================================================================== --- sys/sys/proc.h +++ sys/sys/proc.h @@ -367,6 +367,7 @@ void *td_lkpi_task; /* LinuxKPI task struct pointer */ struct epoch_tracker *td_et; /* (k) compat KPI spare tracker */ int td_pmcpend; + SLIST_HEAD(, epoch_tracker) td_epochs; }; struct thread0_storage { Index: sys/sys/stack.h =================================================================== --- sys/sys/stack.h +++ sys/sys/stack.h @@ -33,6 +33,10 @@ #include +#ifdef _SYS_MALLOC_H_ +MALLOC_DECLARE(M_STACK); +#endif + struct sbuf; /* MI Routines. */