Ehooks comments and cleanup.

This commit is contained in:
David Goldblatt 2019-12-03 17:03:31 -08:00 committed by David Goldblatt
parent c8dae890c8
commit 39fdc690a0
2 changed files with 46 additions and 45 deletions

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@ -1,6 +1,13 @@
#ifndef JEMALLOC_INTERNAL_EHOOKS_H #ifndef JEMALLOC_INTERNAL_EHOOKS_H
#define JEMALLOC_INTERNAL_EHOOKS_H #define JEMALLOC_INTERNAL_EHOOKS_H
/*
* This module is the internal interface to the extent hooks (both
* user-specified and external). Eventually, this will give us the flexibility
* to use multiple different versions of user-visible extent-hook APIs under a
* single user interface.
*/
#include "jemalloc/internal/atomic.h" #include "jemalloc/internal/atomic.h"
extern const extent_hooks_t ehooks_default_extent_hooks; extern const extent_hooks_t ehooks_default_extent_hooks;
@ -13,41 +20,45 @@ struct ehooks_s {
extern const extent_hooks_t ehooks_default_extent_hooks; extern const extent_hooks_t ehooks_default_extent_hooks;
/* NOT PUBLIC. */ /*
* These are not really part of the public API. Each hook has a fast-path for
* the default-hooks case that can avoid various small inefficiencies:
* - Forgetting tsd and then calling tsd_get within the hook.
* - Getting more state than necessary out of the extent_t.
* - Doing arena_ind -> arena -> arena_ind lookups.
* By making the calls to these functions visible to the compiler, it can move
* those extra bits of computation down below the fast-paths where they get ignored.
*/
void *ehooks_default_alloc_impl(tsdn_t *tsdn, void *new_addr, size_t size, void *ehooks_default_alloc_impl(tsdn_t *tsdn, void *new_addr, size_t size,
size_t alignment, bool *zero, bool *commit, unsigned arena_ind); size_t alignment, bool *zero, bool *commit, unsigned arena_ind);
void *ehooks_default_alloc(extent_hooks_t *extent_hooks, void *new_addr,
size_t size, size_t alignment, bool *zero, bool *commit,
unsigned arena_ind);
bool ehooks_default_dalloc_impl(void *addr, size_t size); bool ehooks_default_dalloc_impl(void *addr, size_t size);
bool ehooks_default_dalloc(extent_hooks_t *extent_hooks, void *addr,
size_t size, bool committed, unsigned arena_ind);
void ehooks_default_destroy_impl(void *addr, size_t size); void ehooks_default_destroy_impl(void *addr, size_t size);
void ehooks_default_destroy(extent_hooks_t *extent_hooks, void *addr,
size_t size, bool committed, unsigned arena_ind);
bool ehooks_default_commit_impl(void *addr, size_t offset, size_t length); bool ehooks_default_commit_impl(void *addr, size_t offset, size_t length);
bool ehooks_default_commit(extent_hooks_t *extent_hooks, void *addr, size_t size,
size_t offset, size_t length, unsigned arena_ind);
bool ehooks_default_decommit_impl(void *addr, size_t offset, size_t length); bool ehooks_default_decommit_impl(void *addr, size_t offset, size_t length);
bool ehooks_default_decommit(extent_hooks_t *extent_hooks, void *addr, size_t size,
size_t offset, size_t length, unsigned arena_ind);
#ifdef PAGES_CAN_PURGE_LAZY #ifdef PAGES_CAN_PURGE_LAZY
bool ehooks_default_purge_lazy_impl(void *addr, size_t offset, size_t length); bool ehooks_default_purge_lazy_impl(void *addr, size_t offset, size_t length);
bool ehooks_default_purge_lazy(extent_hooks_t *extent_hooks, void *addr, size_t size,
size_t offset, size_t length, unsigned arena_ind);
#endif #endif
#ifdef PAGES_CAN_PURGE_FORCED #ifdef PAGES_CAN_PURGE_FORCED
bool ehooks_default_purge_forced_impl(void *addr, size_t offset, size_t length); bool ehooks_default_purge_forced_impl(void *addr, size_t offset, size_t length);
bool ehooks_default_purge_forced(extent_hooks_t *extent_hooks, void *addr,
size_t size, size_t offset, size_t length, unsigned arena_ind);
#endif #endif
bool ehooks_default_split_impl(); bool ehooks_default_split_impl();
bool ehooks_default_split(extent_hooks_t *extent_hooks, void *addr, size_t size,
size_t size_a, size_t size_b, bool committed, unsigned arena_ind);
bool ehooks_default_merge_impl(void *addr_a, void *addr_b); bool ehooks_default_merge_impl(void *addr_a, void *addr_b);
bool ehooks_default_merge(extent_hooks_t *extent_hooks, void *addr_a, size_t size_a,
void *addr_b, size_t size_b, bool committed, unsigned arena_ind);
/*
* We don't officially support reentrancy from wtihin the extent hooks. But
* various people who sit within throwing distance of the jemalloc team want
* that functionality in certain limited cases. The default reentrancy guards
* assert that we're not reentrant from a0 (since it's the bootstrap arena,
* where reentrant allocations would be redirected), which we would incorrectly
* trigger in cases where a0 has extent hooks (those hooks themselves can't be
* reentrant, then, but there are reasonable uses for such functionality, like
* putting internal metadata on hugepages). Therefore, we use the raw
* reentrancy guards.
*
* Eventually, we need to think more carefully about whether and where we
* support allocating from within extent hooks (and what that means for things
* like profiling, stats collection, etc.), and document what the guarantee is.
*/
static inline void static inline void
ehooks_pre_reentrancy(tsdn_t *tsdn) { ehooks_pre_reentrancy(tsdn_t *tsdn) {
tsd_t *tsd = tsdn_null(tsdn) ? tsd_fetch() : tsdn_tsd(tsdn); tsd_t *tsd = tsdn_null(tsdn) ? tsd_fetch() : tsdn_tsd(tsdn);
@ -60,7 +71,7 @@ ehooks_post_reentrancy(tsdn_t *tsdn) {
tsd_post_reentrancy_raw(tsd); tsd_post_reentrancy_raw(tsd);
} }
/* PUBLIC. */ /* Beginning of the public API. */
void ehooks_init(ehooks_t *ehooks, extent_hooks_t *extent_hooks); void ehooks_init(ehooks_t *ehooks, extent_hooks_t *extent_hooks);
static inline void static inline void
@ -79,21 +90,11 @@ ehooks_are_default(ehooks_t *ehooks) {
&ehooks_default_extent_hooks; &ehooks_default_extent_hooks;
} }
static inline bool /*
ehooks_destroy_is_noop(ehooks_t *ehooks) { * In some cases, a caller needs to allocate resources before attempting to call
return ehooks_get_extent_hooks_ptr(ehooks)->destroy == NULL; * a hook. If that hook is doomed to fail, this is wasteful. We therefore
} * include some checks for such cases.
*/
static inline bool
ehooks_purge_lazy_will_fail(ehooks_t *ehooks) {
return ehooks_get_extent_hooks_ptr(ehooks)->purge_lazy == NULL;
}
static inline bool
ehooks_purge_forced_will_fail(ehooks_t *ehooks) {
return ehooks_get_extent_hooks_ptr(ehooks)->purge_forced == NULL;
}
static inline bool static inline bool
ehooks_split_will_fail(ehooks_t *ehooks) { ehooks_split_will_fail(ehooks_t *ehooks) {
return ehooks_get_extent_hooks_ptr(ehooks)->split == NULL; return ehooks_get_extent_hooks_ptr(ehooks)->split == NULL;

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@ -57,7 +57,7 @@ ehooks_default_alloc_impl(tsdn_t *tsdn, void *new_addr, size_t size,
return ret; return ret;
} }
void * static void *
ehooks_default_alloc(extent_hooks_t *extent_hooks, void *new_addr, size_t size, ehooks_default_alloc(extent_hooks_t *extent_hooks, void *new_addr, size_t size,
size_t alignment, bool *zero, bool *commit, unsigned arena_ind) { size_t alignment, bool *zero, bool *commit, unsigned arena_ind) {
tsdn_t *tsdn; tsdn_t *tsdn;
@ -84,7 +84,7 @@ ehooks_default_dalloc_impl(void *addr, size_t size) {
return true; return true;
} }
bool static bool
ehooks_default_dalloc(extent_hooks_t *extent_hooks, void *addr, size_t size, ehooks_default_dalloc(extent_hooks_t *extent_hooks, void *addr, size_t size,
bool committed, unsigned arena_ind) { bool committed, unsigned arena_ind) {
return ehooks_default_dalloc_impl(addr, size); return ehooks_default_dalloc_impl(addr, size);
@ -97,7 +97,7 @@ ehooks_default_destroy_impl(void *addr, size_t size) {
} }
} }
void static void
ehooks_default_destroy(extent_hooks_t *extent_hooks, void *addr, size_t size, ehooks_default_destroy(extent_hooks_t *extent_hooks, void *addr, size_t size,
bool committed, unsigned arena_ind) { bool committed, unsigned arena_ind) {
ehooks_default_destroy_impl(addr, size); ehooks_default_destroy_impl(addr, size);
@ -109,7 +109,7 @@ ehooks_default_commit_impl(void *addr, size_t offset, size_t length) {
length); length);
} }
bool static bool
ehooks_default_commit(extent_hooks_t *extent_hooks, void *addr, size_t size, ehooks_default_commit(extent_hooks_t *extent_hooks, void *addr, size_t size,
size_t offset, size_t length, unsigned arena_ind) { size_t offset, size_t length, unsigned arena_ind) {
return ehooks_default_commit_impl(addr, offset, length); return ehooks_default_commit_impl(addr, offset, length);
@ -121,7 +121,7 @@ ehooks_default_decommit_impl(void *addr, size_t offset, size_t length) {
length); length);
} }
bool static bool
ehooks_default_decommit(extent_hooks_t *extent_hooks, void *addr, size_t size, ehooks_default_decommit(extent_hooks_t *extent_hooks, void *addr, size_t size,
size_t offset, size_t length, unsigned arena_ind) { size_t offset, size_t length, unsigned arena_ind) {
return ehooks_default_decommit_impl(addr, offset, length); return ehooks_default_decommit_impl(addr, offset, length);
@ -134,7 +134,7 @@ ehooks_default_purge_lazy_impl(void *addr, size_t offset, size_t length) {
length); length);
} }
bool static bool
ehooks_default_purge_lazy(extent_hooks_t *extent_hooks, void *addr, size_t size, ehooks_default_purge_lazy(extent_hooks_t *extent_hooks, void *addr, size_t size,
size_t offset, size_t length, unsigned arena_ind) { size_t offset, size_t length, unsigned arena_ind) {
assert(addr != NULL); assert(addr != NULL);
@ -152,7 +152,7 @@ ehooks_default_purge_forced_impl(void *addr, size_t offset, size_t length) {
(uintptr_t)offset), length); (uintptr_t)offset), length);
} }
bool static bool
ehooks_default_purge_forced(extent_hooks_t *extent_hooks, void *addr, ehooks_default_purge_forced(extent_hooks_t *extent_hooks, void *addr,
size_t size, size_t offset, size_t length, unsigned arena_ind) { size_t size, size_t offset, size_t length, unsigned arena_ind) {
assert(addr != NULL); assert(addr != NULL);
@ -177,7 +177,7 @@ ehooks_default_split_impl() {
return false; return false;
} }
bool static bool
ehooks_default_split(extent_hooks_t *extent_hooks, void *addr, size_t size, ehooks_default_split(extent_hooks_t *extent_hooks, void *addr, size_t size,
size_t size_a, size_t size_b, bool committed, unsigned arena_ind) { size_t size_a, size_t size_b, bool committed, unsigned arena_ind) {
return ehooks_default_split_impl(); return ehooks_default_split_impl();
@ -195,7 +195,7 @@ ehooks_default_merge_impl(void *addr_a, void *addr_b) {
return false; return false;
} }
bool static bool
ehooks_default_merge(extent_hooks_t *extent_hooks, void *addr_a, size_t size_a, ehooks_default_merge(extent_hooks_t *extent_hooks, void *addr_a, size_t size_a,
void *addr_b, size_t size_b, bool committed, unsigned arena_ind) { void *addr_b, size_t size_b, bool committed, unsigned arena_ind) {
if (!maps_coalesce) { if (!maps_coalesce) {