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author | Stefan Hajnoczi <stefanha@redhat.com> | 2014-07-07 15:15:52 +0200 |
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committer | Kevin Wolf <kwolf@redhat.com> | 2014-08-15 15:07:14 +0200 |
commit | ac2662a913ee5854b1269256adbdc14e57ba480a (patch) | |
tree | 58946f4d817de43cbc5711b6c3b0095ef4f7dade /qemu-coroutine.c | |
parent | 746ebfa77aa7a9550d11d3e7c8c10ecb8393ec76 (diff) | |
download | qemu-ac2662a913ee5854b1269256adbdc14e57ba480a.zip qemu-ac2662a913ee5854b1269256adbdc14e57ba480a.tar.gz qemu-ac2662a913ee5854b1269256adbdc14e57ba480a.tar.bz2 |
coroutine: make pool size dynamic
Allow coroutine users to adjust the pool size. For example, if the
guest has multiple emulated disk drives we should keep around more
coroutines.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Diffstat (limited to 'qemu-coroutine.c')
-rw-r--r-- | qemu-coroutine.c | 26 |
1 files changed, 23 insertions, 3 deletions
diff --git a/qemu-coroutine.c b/qemu-coroutine.c index 4708521..bd574aa 100644 --- a/qemu-coroutine.c +++ b/qemu-coroutine.c @@ -19,14 +19,14 @@ #include "block/coroutine_int.h" enum { - /* Maximum free pool size prevents holding too many freed coroutines */ - POOL_MAX_SIZE = 64, + POOL_DEFAULT_SIZE = 64, }; /** Free list to speed up creation */ static QemuMutex pool_lock; static QSLIST_HEAD(, Coroutine) pool = QSLIST_HEAD_INITIALIZER(pool); static unsigned int pool_size; +static unsigned int pool_max_size = POOL_DEFAULT_SIZE; Coroutine *qemu_coroutine_create(CoroutineEntry *entry) { @@ -55,7 +55,7 @@ static void coroutine_delete(Coroutine *co) { if (CONFIG_COROUTINE_POOL) { qemu_mutex_lock(&pool_lock); - if (pool_size < POOL_MAX_SIZE) { + if (pool_size < pool_max_size) { QSLIST_INSERT_HEAD(&pool, co, pool_next); co->caller = NULL; pool_size++; @@ -137,3 +137,23 @@ void coroutine_fn qemu_coroutine_yield(void) self->caller = NULL; coroutine_swap(self, to); } + +void qemu_coroutine_adjust_pool_size(int n) +{ + qemu_mutex_lock(&pool_lock); + + pool_max_size += n; + + /* Callers should never take away more than they added */ + assert(pool_max_size >= POOL_DEFAULT_SIZE); + + /* Trim oversized pool down to new max */ + while (pool_size > pool_max_size) { + Coroutine *co = QSLIST_FIRST(&pool); + QSLIST_REMOVE_HEAD(&pool, pool_next); + pool_size--; + qemu_coroutine_delete(co); + } + + qemu_mutex_unlock(&pool_lock); +} |