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.

1 files changed, 6 insertions, 0 deletions

diff --git a/manual/install.texi b/manual/install.texi
index 03eb2dd93b..b8deb9ceba 100644
--- a/manual/install.texi
+++ b/manual/install.texi
@@ -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