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Differential D34452 Diff 104219 sys/vm/uma_core.c

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sys/vm/uma_core.c

Show First 20 Lines • Show All 3,488 Lines • ▼ Show 20 Linesitem_domain(void *item)
domain = vm_phys_domain(vtophys(item)); domain = vm_phys_domain(vtophys(item));
KASSERT(domain >= 0 && domain < vm_ndomains, KASSERT(domain >= 0 && domain < vm_ndomains,
("%s: unknown domain for item %p", __func__, item)); ("%s: unknown domain for item %p", __func__, item));
return (domain); return (domain);
} }
#endif #endif
#if defined(INVARIANTS) || defined(DEBUG_MEMGUARD) || defined(WITNESS) #if defined(INVARIANTS) || defined(DEBUG_MEMGUARD) || defined(WITNESS)
#if defined(INVARIANTS) && (defined(DDB) || defined(STACK))
#include <sys/stack.h>
#endif
#define UMA_ZALLOC_DEBUG #define UMA_ZALLOC_DEBUG
static int static int
uma_zalloc_debug(uma_zone_t zone, void **itemp, void *udata, int flags) uma_zalloc_debug(uma_zone_t zone, void **itemp, void *udata, int flags)
{ {
int error; int error;
error = 0; error = 0;
#ifdef WITNESS #ifdef WITNESS
if (flags & M_WAITOK) { if (flags & M_WAITOK) {
WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
"uma_zalloc_debug: zone \"%s\"", zone->uz_name); "uma_zalloc_debug: zone \"%s\"", zone->uz_name);
} }
#endif #endif
#ifdef INVARIANTS #ifdef INVARIANTS
KASSERT((flags & M_EXEC) == 0, KASSERT((flags & M_EXEC) == 0,
("uma_zalloc_debug: called with M_EXEC")); ("uma_zalloc_debug: called with M_EXEC"));
KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(), KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
("uma_zalloc_debug: called within spinlock or critical section")); ("uma_zalloc_debug: called within spinlock or critical section"));
KASSERT((zone->uz_flags & UMA_ZONE_PCPU) == 0 || (flags & M_ZERO) == 0, KASSERT((zone->uz_flags & UMA_ZONE_PCPU) == 0 || (flags & M_ZERO) == 0,
("uma_zalloc_debug: allocating from a pcpu zone with M_ZERO")); ("uma_zalloc_debug: allocating from a pcpu zone with M_ZERO"));
_Static_assert(M_NOWAIT != 0 && M_WAITOK != 0,
"M_NOWAIT and M_WAITOK must be non-zero for this assertion:");
#if 0
/*
* Give the #elif clause time to find problems, then remove it
* and enable this. (Remove <sys/stack.h> above, too.)
*/
KASSERT((flags & (M_NOWAIT|M_WAITOK)) == M_NOWAIT ||
(flags & (M_NOWAIT|M_WAITOK)) == M_WAITOK,
("uma_zalloc_debug: must pass one of M_NOWAIT or M_WAITOK"));
#elif defined(DDB) || defined(STACK)
if (__predict_false((flags & (M_NOWAIT|M_WAITOK)) != M_NOWAIT &&
(flags & (M_NOWAIT|M_WAITOK)) != M_WAITOK)) {
static int stack_count;
struct stack st;
if (stack_count < 10) {
++stack_count;
printf("uma_zalloc* called with bad WAIT flags:\n");
stack_save(&st);
stack_print(&st);
}
}
#endif
#endif #endif
#ifdef DEBUG_MEMGUARD #ifdef DEBUG_MEMGUARD
if ((zone->uz_flags & UMA_ZONE_SMR) == 0 && memguard_cmp_zone(zone)) { if ((zone->uz_flags & UMA_ZONE_SMR) == 0 && memguard_cmp_zone(zone)) {
void *item; void *item;
item = memguard_alloc(zone->uz_size, flags); item = memguard_alloc(zone->uz_size, flags);
if (item != NULL) { if (item != NULL) {
error = EJUSTRETURN; error = EJUSTRETURN;
▲ Show 20 Lines • Show All 127 Lines • ▼ Show 20 Lines KASSERT((zone->uz_flags & UMA_ZONE_SMR) == 0,
("uma_zalloc_arg: called with SMR zone.")); ("uma_zalloc_arg: called with SMR zone."));
if (uma_zalloc_debug(zone, &item, udata, flags) == EJUSTRETURN) if (uma_zalloc_debug(zone, &item, udata, flags) == EJUSTRETURN)
return (item); return (item);
#endif #endif
/* /*
* If possible, allocate from the per-CPU cache. There are two * If possible, allocate from the per-CPU cache. There are two
* requirements for safe access to the per-CPU cache: (1) the thread * requirements for safe access to the per-CPU cache: (1) the thread
* accessing the cache must not be preempted or yield during access, * accessing the cache must not be preempted or yield during access,
vangyzenAuthorUnsubmitted
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I love the irony of hard-coding M_WAITOK here.

vangyzen: I love the irony of hard-coding M_WAITOK here.
rstoneUnsubmitted
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Do we actually have to allocate one here? I thought that struct stack was small enough to be safe to be allocated directly from the stack.

rstone: Do we actually have to allocate one here? I thought that struct stack was small enough to be…
vangyzenAuthorUnsubmitted
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No, we don't. Contrary to the little voice in my head, I tried using this KPI by reading _only the man page_, which clearly says stack_create is required. The src tree tells a different story, where only 1 out of 24 instances uses stack_create. From now on, I'll listen to the voices in my head. No...wait...

D34461 updates the man page.

vangyzen: No, we don't. Contrary to the little voice in my head, I tried using this KPI by reading _only…
* and (2) the thread must not migrate CPUs without switching which * and (2) the thread must not migrate CPUs without switching which
* cache it accesses. We rely on a critical section to prevent * cache it accesses. We rely on a critical section to prevent
* preemption and migration. We release the critical section in * preemption and migration. We release the critical section in
* order to acquire the zone mutex if we are unable to allocate from * order to acquire the zone mutex if we are unable to allocate from
* the current cache; when we re-acquire the critical section, we * the current cache; when we re-acquire the critical section, we
* must detect and handle migration if it has occurred. * must detect and handle migration if it has occurred.
*/ */
critical_enter(); critical_enter();
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