diff options
| author | Andy Lutomirski <luto@kernel.org> | 2016-09-15 22:45:49 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-09-16 09:18:54 +0200 |
| commit | ac496bf48d97f2503eaa353996a4dd5e4383eaf0 (patch) | |
| tree | d57eb8f649cc8268a3d3595f04bbe4bab72264ef /arch/x86/kernel | |
| parent | 68f24b08ee892d47bdef925d676e1ae1ccc316f8 (diff) | |
fork: Optimize task creation by caching two thread stacks per CPU if CONFIG_VMAP_STACK=y
vmalloc() is a bit slow, and pounding vmalloc()/vfree() will eventually
force a global TLB flush.
To reduce pressure on them, if CONFIG_VMAP_STACK=y, cache two thread
stacks per CPU. This will let us quickly allocate a hopefully
cache-hot, TLB-hot stack under heavy forking workloads (shell script style).
On my silly pthread_create() benchmark, it saves about 2 µs per
pthread_create()+join() with CONFIG_VMAP_STACK=y.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jann Horn <jann@thejh.net>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/94811d8e3994b2e962f88866290017d498eb069c.1474003868.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel')
0 files changed, 0 insertions, 0 deletions