mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-21 12:30:06 +00:00
Add per-thread cache to malloc
* config.make.in: Enable experimental malloc option. * configure.ac: Likewise. * configure: Regenerate. * manual/install.texi: Document it. * INSTALL: Regenerate. * malloc/Makefile: Likewise. * malloc/malloc.c: Add per-thread cache (tcache). (tcache_put): New. (tcache_get): New. (tcache_thread_freeres): New. (tcache_init): New. (__libc_malloc): Use cached chunks if available. (__libc_free): Initialize tcache if needed. (__libc_realloc): Likewise. (__libc_calloc): Likewise. (_int_malloc): Prefill tcache when appropriate. (_int_free): Likewise. (do_set_tcache_max): New. (do_set_tcache_count): New. (do_set_tcache_unsorted_limit): New. * manual/probes.texi: Document new probes. * malloc/arena.c: Add new tcache tunables. * elf/dl-tunables.list: Likewise. * manual/tunables.texi: Document them. * NEWS: Mention the per-thread cache.
This commit is contained in:
parent
3cefdd7310
commit
d5c3fafc43
28
ChangeLog
28
ChangeLog
@ -1,3 +1,31 @@
|
||||
2017-07-06 DJ Delorie <dj@delorie.com>
|
||||
|
||||
* config.make.in: Enable experimental malloc option.
|
||||
* configure.ac: Likewise.
|
||||
* configure: Regenerate.
|
||||
* manual/install.texi: Document it.
|
||||
* INSTALL: Regenerate.
|
||||
* malloc/Makefile: Likewise.
|
||||
* malloc/malloc.c: Add per-thread cache (tcache).
|
||||
(tcache_put): New.
|
||||
(tcache_get): New.
|
||||
(tcache_thread_freeres): New.
|
||||
(tcache_init): New.
|
||||
(__libc_malloc): Use cached chunks if available.
|
||||
(__libc_free): Initialize tcache if needed.
|
||||
(__libc_realloc): Likewise.
|
||||
(__libc_calloc): Likewise.
|
||||
(_int_malloc): Prefill tcache when appropriate.
|
||||
(_int_free): Likewise.
|
||||
(do_set_tcache_max): New.
|
||||
(do_set_tcache_count): New.
|
||||
(do_set_tcache_unsorted_limit): New.
|
||||
* manual/probes.texi: Document new probes.
|
||||
* malloc/arena.c: Add new tcache tunables.
|
||||
* elf/dl-tunables.list: Likewise.
|
||||
* manual/tunables.texi: Document them.
|
||||
* NEWS: Mention the per-thread cache.
|
||||
|
||||
2017-07-06 Joseph Myers <joseph@codesourcery.com>
|
||||
|
||||
* iconvdata/tst-loading.c (TIMEOUT): Define to 30.
|
||||
|
6
INSTALL
6
INSTALL
@ -200,6 +200,12 @@ will be used, and CFLAGS sets optimization options for the compiler.
|
||||
libnss_nisplus are not built at all. Use this option to enable
|
||||
libnsl with all depending NSS modules and header files.
|
||||
|
||||
'--disable-experimental-malloc'
|
||||
By default, a per-thread cache is enabled in 'malloc'. While this
|
||||
cache can be disabled on a per-application basis using tunables
|
||||
(set glibc.malloc.tcache_count to zero), this option can be used to
|
||||
remove it from the build completely.
|
||||
|
||||
'--build=BUILD-SYSTEM'
|
||||
'--host=HOST-SYSTEM'
|
||||
These options are for cross-compiling. If you specify both options
|
||||
|
8
NEWS
8
NEWS
@ -9,6 +9,14 @@ Version 2.26
|
||||
|
||||
Major new features:
|
||||
|
||||
* A per-thread cache has been added to malloc. Access to the cache requires
|
||||
no locks and therefore significantly accelerates the fast path to allocate
|
||||
and free small amounts of memory. Refilling an empty cache requires locking
|
||||
the underlying arena. Performance measurements show significant gains in a
|
||||
wide variety of user workloads. Workloads were captured using a special
|
||||
instrumented malloc and analyzed with a malloc simulator. Contributed by
|
||||
DJ Delorie with the help of Florian Weimer, and Carlos O'Donell.
|
||||
|
||||
* Unicode 10.0.0 Support: Character encoding, character type info, and
|
||||
transliteration tables are all updated to Unicode 10.0.0, using
|
||||
generator scripts contributed by Mike FABIAN (Red Hat).
|
||||
|
@ -78,6 +78,8 @@ multi-arch = @multi_arch@
|
||||
|
||||
mach-interface-list = @mach_interface_list@
|
||||
|
||||
experimental-malloc = @experimental_malloc@
|
||||
|
||||
nss-crypt = @libc_cv_nss_crypt@
|
||||
static-nss-crypt = @libc_cv_static_nss_crypt@
|
||||
|
||||
|
13
configure
vendored
13
configure
vendored
@ -674,6 +674,7 @@ build_obsolete_nsl
|
||||
link_obsolete_rpc
|
||||
libc_cv_static_nss_crypt
|
||||
libc_cv_nss_crypt
|
||||
experimental_malloc
|
||||
enable_werror
|
||||
all_warnings
|
||||
force_install
|
||||
@ -779,6 +780,7 @@ enable_kernel
|
||||
enable_all_warnings
|
||||
enable_werror
|
||||
enable_multi_arch
|
||||
enable_experimental_malloc
|
||||
enable_nss_crypt
|
||||
enable_obsolete_rpc
|
||||
enable_obsolete_nsl
|
||||
@ -1450,6 +1452,8 @@ Optional Features:
|
||||
--disable-werror do not build with -Werror
|
||||
--enable-multi-arch enable single DSO with optimizations for multiple
|
||||
architectures
|
||||
--disable-experimental-malloc
|
||||
disable experimental malloc features
|
||||
--enable-nss-crypt enable libcrypt to use nss
|
||||
--enable-obsolete-rpc build and install the obsolete RPC code for
|
||||
link-time usage
|
||||
@ -3522,6 +3526,15 @@ else
|
||||
fi
|
||||
|
||||
|
||||
# Check whether --enable-experimental-malloc was given.
|
||||
if test "${enable_experimental_malloc+set}" = set; then :
|
||||
enableval=$enable_experimental_malloc; experimental_malloc=$enableval
|
||||
else
|
||||
experimental_malloc=yes
|
||||
fi
|
||||
|
||||
|
||||
|
||||
# Check whether --enable-nss-crypt was given.
|
||||
if test "${enable_nss_crypt+set}" = set; then :
|
||||
enableval=$enable_nss_crypt; nss_crypt=$enableval
|
||||
|
@ -313,6 +313,13 @@ AC_ARG_ENABLE([multi-arch],
|
||||
[multi_arch=$enableval],
|
||||
[multi_arch=default])
|
||||
|
||||
AC_ARG_ENABLE([experimental-malloc],
|
||||
AC_HELP_STRING([--disable-experimental-malloc],
|
||||
[disable experimental malloc features]),
|
||||
[experimental_malloc=$enableval],
|
||||
[experimental_malloc=yes])
|
||||
AC_SUBST(experimental_malloc)
|
||||
|
||||
AC_ARG_ENABLE([nss-crypt],
|
||||
AC_HELP_STRING([--enable-nss-crypt],
|
||||
[enable libcrypt to use nss]),
|
||||
|
@ -76,6 +76,18 @@ glibc {
|
||||
minval: 1
|
||||
security_level: SXID_IGNORE
|
||||
}
|
||||
tcache_max {
|
||||
type: SIZE_T
|
||||
security_level: SXID_ERASE
|
||||
}
|
||||
tcache_count {
|
||||
type: SIZE_T
|
||||
security_level: SXID_ERASE
|
||||
}
|
||||
tcache_unsorted_limit {
|
||||
type: SIZE_T
|
||||
security_level: SXID_ERASE
|
||||
}
|
||||
}
|
||||
tune {
|
||||
hwcap_mask {
|
||||
|
@ -189,6 +189,11 @@ tst-malloc-usable-static-ENV = $(tst-malloc-usable-ENV)
|
||||
tst-malloc-usable-tunables-ENV = GLIBC_TUNABLES=glibc.malloc.check=3
|
||||
tst-malloc-usable-static-tunables-ENV = $(tst-malloc-usable-tunables-ENV)
|
||||
|
||||
ifeq ($(experimental-malloc),yes)
|
||||
CPPFLAGS-malloc.c += -DUSE_TCACHE=1
|
||||
else
|
||||
CPPFLAGS-malloc.c += -DUSE_TCACHE=0
|
||||
endif
|
||||
# Uncomment this for test releases. For public releases it is too expensive.
|
||||
#CPPFLAGS-malloc.o += -DMALLOC_DEBUG=1
|
||||
|
||||
|
@ -236,6 +236,11 @@ TUNABLE_CALLBACK_FNDECL (set_perturb_byte, int32_t)
|
||||
TUNABLE_CALLBACK_FNDECL (set_trim_threshold, size_t)
|
||||
TUNABLE_CALLBACK_FNDECL (set_arena_max, size_t)
|
||||
TUNABLE_CALLBACK_FNDECL (set_arena_test, size_t)
|
||||
#if USE_TCACHE
|
||||
TUNABLE_CALLBACK_FNDECL (set_tcache_max, size_t)
|
||||
TUNABLE_CALLBACK_FNDECL (set_tcache_count, size_t)
|
||||
TUNABLE_CALLBACK_FNDECL (set_tcache_unsorted_limit, size_t)
|
||||
#endif
|
||||
#else
|
||||
/* Initialization routine. */
|
||||
#include <string.h>
|
||||
@ -322,6 +327,12 @@ ptmalloc_init (void)
|
||||
TUNABLE_GET (mmap_max, int32_t, TUNABLE_CALLBACK (set_mmaps_max));
|
||||
TUNABLE_GET (arena_max, size_t, TUNABLE_CALLBACK (set_arena_max));
|
||||
TUNABLE_GET (arena_test, size_t, TUNABLE_CALLBACK (set_arena_test));
|
||||
#if USE_TCACHE
|
||||
TUNABLE_GET (tcache_max, size_t, TUNABLE_CALLBACK (set_tcache_max));
|
||||
TUNABLE_GET (tcache_count, size_t, TUNABLE_CALLBACK (set_tcache_count));
|
||||
TUNABLE_GET (tcache_unsorted_limit, size_t,
|
||||
TUNABLE_CALLBACK (set_tcache_unsorted_limit));
|
||||
#endif
|
||||
__libc_lock_unlock (main_arena.mutex);
|
||||
#else
|
||||
const char *s = NULL;
|
||||
|
350
malloc/malloc.c
350
malloc/malloc.c
@ -238,6 +238,9 @@
|
||||
/* For ALIGN_UP et. al. */
|
||||
#include <libc-pointer-arith.h>
|
||||
|
||||
/* For DIAG_PUSH/POP_NEEDS_COMMENT et al. */
|
||||
#include <libc-diag.h>
|
||||
|
||||
#include <malloc/malloc-internal.h>
|
||||
|
||||
/*
|
||||
@ -296,6 +299,30 @@ __malloc_assert (const char *assertion, const char *file, unsigned int line,
|
||||
}
|
||||
#endif
|
||||
|
||||
#if USE_TCACHE
|
||||
/* We want 64 entries. This is an arbitrary limit, which tunables can reduce. */
|
||||
# define TCACHE_MAX_BINS 64
|
||||
# define MAX_TCACHE_SIZE tidx2usize (TCACHE_MAX_BINS-1)
|
||||
|
||||
/* Only used to pre-fill the tunables. */
|
||||
# define tidx2usize(idx) (((size_t) idx) * MALLOC_ALIGNMENT + MINSIZE - SIZE_SZ)
|
||||
|
||||
/* When "x" is from chunksize(). */
|
||||
# define csize2tidx(x) (((x) - MINSIZE + MALLOC_ALIGNMENT - 1) / MALLOC_ALIGNMENT)
|
||||
/* When "x" is a user-provided size. */
|
||||
# define usize2tidx(x) csize2tidx (request2size (x))
|
||||
|
||||
/* With rounding and alignment, the bins are...
|
||||
idx 0 bytes 0..24 (64-bit) or 0..12 (32-bit)
|
||||
idx 1 bytes 25..40 or 13..20
|
||||
idx 2 bytes 41..56 or 21..28
|
||||
etc. */
|
||||
|
||||
/* This is another arbitrary limit, which tunables can change. Each
|
||||
tcache bin will hold at most this number of chunks. */
|
||||
# define TCACHE_FILL_COUNT 7
|
||||
#endif
|
||||
|
||||
|
||||
/*
|
||||
REALLOC_ZERO_BYTES_FREES should be set if a call to
|
||||
@ -1712,6 +1739,17 @@ struct malloc_par
|
||||
|
||||
/* First address handed out by MORECORE/sbrk. */
|
||||
char *sbrk_base;
|
||||
|
||||
#if USE_TCACHE
|
||||
/* Maximum number of buckets to use. */
|
||||
size_t tcache_bins;
|
||||
size_t tcache_max_bytes;
|
||||
/* Maximum number of chunks in each bucket. */
|
||||
size_t tcache_count;
|
||||
/* Maximum number of chunks to remove from the unsorted list, which
|
||||
aren't used to prefill the cache. */
|
||||
size_t tcache_unsorted_limit;
|
||||
#endif
|
||||
};
|
||||
|
||||
/* There are several instances of this struct ("arenas") in this
|
||||
@ -1750,6 +1788,13 @@ static struct malloc_par mp_ =
|
||||
.trim_threshold = DEFAULT_TRIM_THRESHOLD,
|
||||
#define NARENAS_FROM_NCORES(n) ((n) * (sizeof (long) == 4 ? 2 : 8))
|
||||
.arena_test = NARENAS_FROM_NCORES (1)
|
||||
#if USE_TCACHE
|
||||
,
|
||||
.tcache_count = TCACHE_FILL_COUNT,
|
||||
.tcache_bins = TCACHE_MAX_BINS,
|
||||
.tcache_max_bytes = tidx2usize (TCACHE_MAX_BINS-1),
|
||||
.tcache_unsorted_limit = 0 /* No limit. */
|
||||
#endif
|
||||
};
|
||||
|
||||
/* Maximum size of memory handled in fastbins. */
|
||||
@ -2875,6 +2920,124 @@ mremap_chunk (mchunkptr p, size_t new_size)
|
||||
|
||||
/*------------------------ Public wrappers. --------------------------------*/
|
||||
|
||||
#if USE_TCACHE
|
||||
|
||||
/* We overlay this structure on the user-data portion of a chunk when
|
||||
the chunk is stored in the per-thread cache. */
|
||||
typedef struct tcache_entry
|
||||
{
|
||||
struct tcache_entry *next;
|
||||
} tcache_entry;
|
||||
|
||||
/* There is one of these for each thread, which contains the
|
||||
per-thread cache (hence "tcache_perthread_struct"). Keeping
|
||||
overall size low is mildly important. Note that COUNTS and ENTRIES
|
||||
are redundant (we could have just counted the linked list each
|
||||
time), this is for performance reasons. */
|
||||
typedef struct tcache_perthread_struct
|
||||
{
|
||||
char counts[TCACHE_MAX_BINS];
|
||||
tcache_entry *entries[TCACHE_MAX_BINS];
|
||||
} tcache_perthread_struct;
|
||||
|
||||
static __thread char tcache_shutting_down = 0;
|
||||
static __thread tcache_perthread_struct *tcache = NULL;
|
||||
|
||||
/* Caller must ensure that we know tc_idx is valid and there's room
|
||||
for more chunks. */
|
||||
static void
|
||||
tcache_put (mchunkptr chunk, size_t tc_idx)
|
||||
{
|
||||
tcache_entry *e = (tcache_entry *) chunk2mem (chunk);
|
||||
assert (tc_idx < TCACHE_MAX_BINS);
|
||||
e->next = tcache->entries[tc_idx];
|
||||
tcache->entries[tc_idx] = e;
|
||||
++(tcache->counts[tc_idx]);
|
||||
}
|
||||
|
||||
/* Caller must ensure that we know tc_idx is valid and there's
|
||||
available chunks to remove. */
|
||||
static void *
|
||||
tcache_get (size_t tc_idx)
|
||||
{
|
||||
tcache_entry *e = tcache->entries[tc_idx];
|
||||
assert (tc_idx < TCACHE_MAX_BINS);
|
||||
assert (tcache->entries[tc_idx] > 0);
|
||||
tcache->entries[tc_idx] = e->next;
|
||||
--(tcache->counts[tc_idx]);
|
||||
return (void *) e;
|
||||
}
|
||||
|
||||
static void __attribute__ ((section ("__libc_thread_freeres_fn")))
|
||||
tcache_thread_freeres (void)
|
||||
{
|
||||
int i;
|
||||
tcache_perthread_struct *tcache_tmp = tcache;
|
||||
|
||||
if (!tcache)
|
||||
return;
|
||||
|
||||
tcache = NULL;
|
||||
|
||||
for (i = 0; i < TCACHE_MAX_BINS; ++i)
|
||||
{
|
||||
while (tcache_tmp->entries[i])
|
||||
{
|
||||
tcache_entry *e = tcache_tmp->entries[i];
|
||||
tcache_tmp->entries[i] = e->next;
|
||||
__libc_free (e);
|
||||
}
|
||||
}
|
||||
|
||||
__libc_free (tcache_tmp);
|
||||
|
||||
tcache_shutting_down = 1;
|
||||
}
|
||||
text_set_element (__libc_thread_subfreeres, tcache_thread_freeres);
|
||||
|
||||
static void
|
||||
tcache_init(void)
|
||||
{
|
||||
mstate ar_ptr;
|
||||
void *victim = 0;
|
||||
const size_t bytes = sizeof (tcache_perthread_struct);
|
||||
|
||||
if (tcache_shutting_down)
|
||||
return;
|
||||
|
||||
arena_get (ar_ptr, bytes);
|
||||
victim = _int_malloc (ar_ptr, bytes);
|
||||
if (!victim && ar_ptr != NULL)
|
||||
{
|
||||
ar_ptr = arena_get_retry (ar_ptr, bytes);
|
||||
victim = _int_malloc (ar_ptr, bytes);
|
||||
}
|
||||
|
||||
|
||||
if (ar_ptr != NULL)
|
||||
__libc_lock_unlock (ar_ptr->mutex);
|
||||
|
||||
/* In a low memory situation, we may not be able to allocate memory
|
||||
- in which case, we just keep trying later. However, we
|
||||
typically do this very early, so either there is sufficient
|
||||
memory, or there isn't enough memory to do non-trivial
|
||||
allocations anyway. */
|
||||
if (victim)
|
||||
{
|
||||
tcache = (tcache_perthread_struct *) victim;
|
||||
memset (tcache, 0, sizeof (tcache_perthread_struct));
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
#define MAYBE_INIT_TCACHE() \
|
||||
if (__glibc_unlikely (tcache == NULL)) \
|
||||
tcache_init();
|
||||
|
||||
#else
|
||||
#define MAYBE_INIT_TCACHE()
|
||||
#endif
|
||||
|
||||
void *
|
||||
__libc_malloc (size_t bytes)
|
||||
{
|
||||
@ -2885,6 +3048,23 @@ __libc_malloc (size_t bytes)
|
||||
= atomic_forced_read (__malloc_hook);
|
||||
if (__builtin_expect (hook != NULL, 0))
|
||||
return (*hook)(bytes, RETURN_ADDRESS (0));
|
||||
#if USE_TCACHE
|
||||
/* int_free also calls request2size, be careful to not pad twice. */
|
||||
size_t tbytes = request2size (bytes);
|
||||
size_t tc_idx = csize2tidx (tbytes);
|
||||
|
||||
MAYBE_INIT_TCACHE ();
|
||||
|
||||
DIAG_PUSH_NEEDS_COMMENT;
|
||||
if (tc_idx < mp_.tcache_bins
|
||||
/*&& tc_idx < TCACHE_MAX_BINS*/ /* to appease gcc */
|
||||
&& tcache
|
||||
&& tcache->entries[tc_idx] != NULL)
|
||||
{
|
||||
return tcache_get (tc_idx);
|
||||
}
|
||||
DIAG_POP_NEEDS_COMMENT;
|
||||
#endif
|
||||
|
||||
arena_get (ar_ptr, bytes);
|
||||
|
||||
@ -2944,6 +3124,8 @@ __libc_free (void *mem)
|
||||
return;
|
||||
}
|
||||
|
||||
MAYBE_INIT_TCACHE ();
|
||||
|
||||
ar_ptr = arena_for_chunk (p);
|
||||
_int_free (ar_ptr, p, 0);
|
||||
}
|
||||
@ -2981,7 +3163,10 @@ __libc_realloc (void *oldmem, size_t bytes)
|
||||
if (chunk_is_mmapped (oldp))
|
||||
ar_ptr = NULL;
|
||||
else
|
||||
ar_ptr = arena_for_chunk (oldp);
|
||||
{
|
||||
MAYBE_INIT_TCACHE ();
|
||||
ar_ptr = arena_for_chunk (oldp);
|
||||
}
|
||||
|
||||
/* Little security check which won't hurt performance: the allocator
|
||||
never wrapps around at the end of the address space. Therefore
|
||||
@ -3206,6 +3391,8 @@ __libc_calloc (size_t n, size_t elem_size)
|
||||
|
||||
sz = bytes;
|
||||
|
||||
MAYBE_INIT_TCACHE ();
|
||||
|
||||
arena_get (av, sz);
|
||||
if (av)
|
||||
{
|
||||
@ -3336,6 +3523,10 @@ _int_malloc (mstate av, size_t bytes)
|
||||
mchunkptr fwd; /* misc temp for linking */
|
||||
mchunkptr bck; /* misc temp for linking */
|
||||
|
||||
#if USE_TCACHE
|
||||
size_t tcache_unsorted_count; /* count of unsorted chunks processed */
|
||||
#endif
|
||||
|
||||
const char *errstr = NULL;
|
||||
|
||||
/*
|
||||
@ -3365,19 +3556,22 @@ _int_malloc (mstate av, size_t bytes)
|
||||
can try it without checking, which saves some time on this fast path.
|
||||
*/
|
||||
|
||||
#define REMOVE_FB(fb, victim, pp) \
|
||||
do \
|
||||
{ \
|
||||
victim = pp; \
|
||||
if (victim == NULL) \
|
||||
break; \
|
||||
} \
|
||||
while ((pp = catomic_compare_and_exchange_val_acq (fb, victim->fd, victim)) \
|
||||
!= victim); \
|
||||
|
||||
if ((unsigned long) (nb) <= (unsigned long) (get_max_fast ()))
|
||||
{
|
||||
idx = fastbin_index (nb);
|
||||
mfastbinptr *fb = &fastbin (av, idx);
|
||||
mchunkptr pp = *fb;
|
||||
do
|
||||
{
|
||||
victim = pp;
|
||||
if (victim == NULL)
|
||||
break;
|
||||
}
|
||||
while ((pp = catomic_compare_and_exchange_val_acq (fb, victim->fd, victim))
|
||||
!= victim);
|
||||
REMOVE_FB (fb, victim, pp);
|
||||
if (victim != 0)
|
||||
{
|
||||
if (__builtin_expect (fastbin_index (chunksize (victim)) != idx, 0))
|
||||
@ -3388,6 +3582,26 @@ _int_malloc (mstate av, size_t bytes)
|
||||
return NULL;
|
||||
}
|
||||
check_remalloced_chunk (av, victim, nb);
|
||||
#if USE_TCACHE
|
||||
/* While we're here, if we see other chunks of the same size,
|
||||
stash them in the tcache. */
|
||||
size_t tc_idx = csize2tidx (nb);
|
||||
if (tcache && tc_idx < mp_.tcache_bins)
|
||||
{
|
||||
mchunkptr tc_victim;
|
||||
|
||||
/* While bin not empty and tcache not full, copy chunks over. */
|
||||
while (tcache->counts[tc_idx] < mp_.tcache_count
|
||||
&& (pp = *fb) != NULL)
|
||||
{
|
||||
REMOVE_FB (fb, tc_victim, pp);
|
||||
if (tc_victim != 0)
|
||||
{
|
||||
tcache_put (tc_victim, tc_idx);
|
||||
}
|
||||
}
|
||||
}
|
||||
#endif
|
||||
void *p = chunk2mem (victim);
|
||||
alloc_perturb (p, bytes);
|
||||
return p;
|
||||
@ -3426,6 +3640,32 @@ _int_malloc (mstate av, size_t bytes)
|
||||
if (av != &main_arena)
|
||||
set_non_main_arena (victim);
|
||||
check_malloced_chunk (av, victim, nb);
|
||||
#if USE_TCACHE
|
||||
/* While we're here, if we see other chunks of the same size,
|
||||
stash them in the tcache. */
|
||||
size_t tc_idx = csize2tidx (nb);
|
||||
if (tcache && tc_idx < mp_.tcache_bins)
|
||||
{
|
||||
mchunkptr tc_victim;
|
||||
|
||||
/* While bin not empty and tcache not full, copy chunks over. */
|
||||
while (tcache->counts[tc_idx] < mp_.tcache_count
|
||||
&& (tc_victim = last (bin)) != bin)
|
||||
{
|
||||
if (tc_victim != 0)
|
||||
{
|
||||
bck = tc_victim->bk;
|
||||
set_inuse_bit_at_offset (tc_victim, nb);
|
||||
if (av != &main_arena)
|
||||
set_non_main_arena (tc_victim);
|
||||
bin->bk = bck;
|
||||
bck->fd = bin;
|
||||
|
||||
tcache_put (tc_victim, tc_idx);
|
||||
}
|
||||
}
|
||||
}
|
||||
#endif
|
||||
void *p = chunk2mem (victim);
|
||||
alloc_perturb (p, bytes);
|
||||
return p;
|
||||
@ -3464,6 +3704,16 @@ _int_malloc (mstate av, size_t bytes)
|
||||
otherwise need to expand memory to service a "small" request.
|
||||
*/
|
||||
|
||||
#if USE_TCACHE
|
||||
INTERNAL_SIZE_T tcache_nb = 0;
|
||||
size_t tc_idx = csize2tidx (nb);
|
||||
if (tcache && tc_idx < mp_.tcache_bins)
|
||||
tcache_nb = nb;
|
||||
int return_cached = 0;
|
||||
|
||||
tcache_unsorted_count = 0;
|
||||
#endif
|
||||
|
||||
for (;; )
|
||||
{
|
||||
int iters = 0;
|
||||
@ -3524,10 +3774,26 @@ _int_malloc (mstate av, size_t bytes)
|
||||
set_inuse_bit_at_offset (victim, size);
|
||||
if (av != &main_arena)
|
||||
set_non_main_arena (victim);
|
||||
#if USE_TCACHE
|
||||
/* Fill cache first, return to user only if cache fills.
|
||||
We may return one of these chunks later. */
|
||||
if (tcache_nb
|
||||
&& tcache->counts[tc_idx] < mp_.tcache_count)
|
||||
{
|
||||
tcache_put (victim, tc_idx);
|
||||
return_cached = 1;
|
||||
continue;
|
||||
}
|
||||
else
|
||||
{
|
||||
#endif
|
||||
check_malloced_chunk (av, victim, nb);
|
||||
void *p = chunk2mem (victim);
|
||||
alloc_perturb (p, bytes);
|
||||
return p;
|
||||
#if USE_TCACHE
|
||||
}
|
||||
#endif
|
||||
}
|
||||
|
||||
/* place chunk in bin */
|
||||
@ -3594,11 +3860,31 @@ _int_malloc (mstate av, size_t bytes)
|
||||
fwd->bk = victim;
|
||||
bck->fd = victim;
|
||||
|
||||
#if USE_TCACHE
|
||||
/* If we've processed as many chunks as we're allowed while
|
||||
filling the cache, return one of the cached ones. */
|
||||
++tcache_unsorted_count;
|
||||
if (return_cached
|
||||
&& mp_.tcache_unsorted_limit > 0
|
||||
&& tcache_unsorted_count > mp_.tcache_unsorted_limit)
|
||||
{
|
||||
return tcache_get (tc_idx);
|
||||
}
|
||||
#endif
|
||||
|
||||
#define MAX_ITERS 10000
|
||||
if (++iters >= MAX_ITERS)
|
||||
break;
|
||||
}
|
||||
|
||||
#if USE_TCACHE
|
||||
/* If all the small chunks we found ended up cached, return one now. */
|
||||
if (return_cached)
|
||||
{
|
||||
return tcache_get (tc_idx);
|
||||
}
|
||||
#endif
|
||||
|
||||
/*
|
||||
If a large request, scan through the chunks of current bin in
|
||||
sorted order to find smallest that fits. Use the skip list for this.
|
||||
@ -3884,6 +4170,20 @@ _int_free (mstate av, mchunkptr p, int have_lock)
|
||||
|
||||
check_inuse_chunk(av, p);
|
||||
|
||||
#if USE_TCACHE
|
||||
{
|
||||
size_t tc_idx = csize2tidx (size);
|
||||
|
||||
if (tcache
|
||||
&& tc_idx < mp_.tcache_bins
|
||||
&& tcache->counts[tc_idx] < mp_.tcache_count)
|
||||
{
|
||||
tcache_put (p, tc_idx);
|
||||
return;
|
||||
}
|
||||
}
|
||||
#endif
|
||||
|
||||
/*
|
||||
If eligible, place chunk on a fastbin so it can be found
|
||||
and used quickly in malloc.
|
||||
@ -4845,6 +5145,38 @@ do_set_arena_max (size_t value)
|
||||
return 1;
|
||||
}
|
||||
|
||||
#if USE_TCACHE
|
||||
static inline int
|
||||
__always_inline
|
||||
do_set_tcache_max (size_t value)
|
||||
{
|
||||
if (value >= 0 && value <= MAX_TCACHE_SIZE)
|
||||
{
|
||||
LIBC_PROBE (memory_tunable_tcache_max_bytes, 2, value, mp_.tcache_max_bytes);
|
||||
mp_.tcache_max_bytes = value;
|
||||
mp_.tcache_bins = csize2tidx (request2size(value)) + 1;
|
||||
}
|
||||
return 1;
|
||||
}
|
||||
|
||||
static inline int
|
||||
__always_inline
|
||||
do_set_tcache_count (size_t value)
|
||||
{
|
||||
LIBC_PROBE (memory_tunable_tcache_count, 2, value, mp_.tcache_count);
|
||||
mp_.tcache_count = value;
|
||||
return 1;
|
||||
}
|
||||
|
||||
static inline int
|
||||
__always_inline
|
||||
do_set_tcache_unsorted_limit (size_t value)
|
||||
{
|
||||
LIBC_PROBE (memory_tunable_tcache_unsorted_limit, 2, value, mp_.tcache_unsorted_limit);
|
||||
mp_.tcache_unsorted_limit = value;
|
||||
return 1;
|
||||
}
|
||||
#endif
|
||||
|
||||
int
|
||||
__libc_mallopt (int param_number, int value)
|
||||
|
@ -232,6 +232,12 @@ libnss_nisplus are not built at all.
|
||||
Use this option to enable libnsl with all depending NSS modules and
|
||||
header files.
|
||||
|
||||
@item --disable-experimental-malloc
|
||||
By default, a per-thread cache is enabled in @code{malloc}. While
|
||||
this cache can be disabled on a per-application basis using tunables
|
||||
(set glibc.malloc.tcache_count to zero), this option can be used to
|
||||
remove it from the build completely.
|
||||
|
||||
@item --build=@var{build-system}
|
||||
@itemx --host=@var{host-system}
|
||||
These options are for cross-compiling. If you specify both options and
|
||||
|
@ -231,6 +231,25 @@ dynamic brk/mmap thresholds. Argument @var{$arg1} and @var{$arg2} are
|
||||
the adjusted mmap and trim thresholds, respectively.
|
||||
@end deftp
|
||||
|
||||
@deftp Probe memory_tunable_tcache_max_bytes (int @var{$arg1}, int @var{$arg2})
|
||||
This probe is triggered when the @code{glibc.malloc.tcache_max}
|
||||
tunable is set. Argument @var{$arg1} is the requested value, and
|
||||
@var{$arg2} is the previous value of this tunable.
|
||||
@end deftp
|
||||
|
||||
@deftp Probe memory_tunable_tcache_count (int @var{$arg1}, int @var{$arg2})
|
||||
This probe is triggered when the @code{glibc.malloc.tcache_count}
|
||||
tunable is set. Argument @var{$arg1} is the requested value, and
|
||||
@var{$arg2} is the previous value of this tunable.
|
||||
@end deftp
|
||||
|
||||
@deftp Probe memory_tunable_tcache_unsorted_limit (int @var{$arg1}, int @var{$arg2})
|
||||
This probe is triggered when the
|
||||
@code{glibc.malloc.tcache_unsorted_limit} tunable is set. Argument
|
||||
@var{$arg1} is the requested value, and @var{$arg2} is the previous
|
||||
value of this tunable.
|
||||
@end deftp
|
||||
|
||||
@node Mathematical Function Probes
|
||||
@section Mathematical Function Probes
|
||||
|
||||
|
@ -193,6 +193,38 @@ systems the limit is twice the number of cores online and on 64-bit systems, it
|
||||
is 8 times the number of cores online.
|
||||
@end deftp
|
||||
|
||||
@deftp Tunable glibc.malloc.tcache_max
|
||||
The maximum size of a request (in bytes) which may be met via the
|
||||
per-thread cache. The default (and maximum) value is 1032 bytes on
|
||||
64-bit systems and 516 bytes on 32-bit systems.
|
||||
@end deftp
|
||||
|
||||
@deftp Tunable glibc.malloc.tcache_count
|
||||
The maximum number of chunks of each size to cache. The default is 7.
|
||||
There is no upper limit, other than available system memory. If set
|
||||
to zero, the per-thread cache is effectively disabled.
|
||||
|
||||
The approximate maximum overhead of the per-thread cache is thus equal
|
||||
to the number of bins times the chunk count in each bin times the size
|
||||
of each chunk. With defaults, the approximate maximum overhead of the
|
||||
per-thread cache is approximately 236 KB on 64-bit systems and 118 KB
|
||||
on 32-bit systems.
|
||||
@end deftp
|
||||
|
||||
@deftp Tunable glibc.malloc.tcache_unsorted_limit
|
||||
When the user requests memory and the request cannot be met via the
|
||||
per-thread cache, the arenas are used to meet the request. At this
|
||||
time, additional chunks will be moved from existing arena lists to
|
||||
pre-fill the corresponding cache. While copies from the fastbins,
|
||||
smallbins, and regular bins are bounded and predictable due to the bin
|
||||
sizes, copies from the unsorted bin are not bounded, and incur
|
||||
additional time penalties as they need to be sorted as they're
|
||||
scanned. To make scanning the unsorted list more predictable and
|
||||
bounded, the user may set this tunable to limit the number of chunks
|
||||
that are scanned from the unsorted list while searching for chunks to
|
||||
pre-fill the per-thread cache with. The default, or when set to zero,
|
||||
is no limit.
|
||||
|
||||
@node Hardware Capability Tunables
|
||||
@section Hardware Capability Tunables
|
||||
@cindex hardware capability tunables
|
||||
|
Loading…
Reference in New Issue
Block a user