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/INSTALL b/INSTALL
index 5c745244a6..0ff87ed603 100644
--- a/INSTALL
+++ b/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