| commit | fe5c13ebf1161d0f324229cfb36cb5fb87ec6248 | |
| author | Avi Kivity <avi@redhat.com> | |
| Mon, 5 Dec 2011 17:20:12 +0000 (5 19:20 +0200) | ||
| committer | Justin M. Forbes <jforbes@redhat.com> | |
| Tue, 10 Jan 2012 19:36:39 +0000 (10 13:36 -0600) | ||
| tree | 9f5df68149392c00027a2f0693ca7393d9051aa9 | treesnapshot (tar.gz zip) |
| parent | 6061f16a8a119a46e61f2ddbabdb58f83e8857f7 | commitdiff |
coroutine: switch per-thread free pool to a global pool
ucontext-based coroutines use a free pool to reduce allocations and
deallocations of coroutine objects. The pool is per-thread, presumably
to improve locality. However, as coroutines are usually allocated in
a vcpu thread and freed in the I/O thread, the pool accounting gets
screwed up and we end allocating and freeing a coroutine for every I/O
request. This is expensive since large objects are allocated via the
kernel, and are not cached by the C runtime.
Fix by switching to a global pool. This is safe since we're protected
by the global mutex.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
ucontext-based coroutines use a free pool to reduce allocations and
deallocations of coroutine objects. The pool is per-thread, presumably
to improve locality. However, as coroutines are usually allocated in
a vcpu thread and freed in the I/O thread, the pool accounting gets
screwed up and we end allocating and freeing a coroutine for every I/O
request. This is expensive since large objects are allocated via the
kernel, and are not cached by the C runtime.
Fix by switching to a global pool. This is safe since we're protected
by the global mutex.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
| coroutine-ucontext.c | diffblobblamehistory |