Message ID | 1369280289-20928-10-git-send-email-famz@redhat.com |
---|---|
State | New |
Headers | show |
On Thu, May 23, 2013 at 11:38:07AM +0800, Fam Zheng wrote: > Introduce a cache quota: BDRVCURLState.cache_quota. > When adding new CURLDataCache to BDRVCURLState, if number of existing > CURLDataCache is larger than CURL_CACHE_QUOTA, try to release some first > to limit the in memory cache size. > > A least used entry is selected for releasing. > > Signed-off-by: Fam Zheng <famz@redhat.com> > --- > block/curl.c | 27 +++++++++++++++++++++++++++ > 1 file changed, 27 insertions(+) > > diff --git a/block/curl.c b/block/curl.c > index 3ea2552..5adbc84 100644 > --- a/block/curl.c > +++ b/block/curl.c > @@ -40,6 +40,7 @@ > > #define SECTOR_SIZE 512 > #define READ_AHEAD_SIZE (256 * 1024) > +#define CURL_CACHE_QUOTA 10 > > struct BDRVCURLState; > > @@ -90,6 +91,8 @@ typedef struct BDRVCURLState { > QEMUTimer *timer; > /* List of data cache ordered by access, freed from tail */ > QLIST_HEAD(, CURLDataCache) cache; > + /* Threshold to release unused cache when cache list is longer than it */ > + int cache_quota; > /* Whether http server accept range in header */ > bool accept_range; > } BDRVCURLState; > @@ -526,6 +529,8 @@ static int curl_open(BlockDriverState *bs, QDict *options, int flags) > curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running); > > qemu_opts_del(opts); > + s->cache_quota = CURL_CACHE_QUOTA; > + > return 0; > > out: > @@ -595,6 +600,27 @@ static void curl_readv_bh_cb(void *p) > cache->data_len = aio_bytes + s->readahead_size; > cache->write_pos = 0; > cache->data = g_malloc(cache->data_len); > + /* Try to release some cache */ > + while (0 && s->cache_quota <= 0) { while (0) :(
diff --git a/block/curl.c b/block/curl.c index 3ea2552..5adbc84 100644 --- a/block/curl.c +++ b/block/curl.c @@ -40,6 +40,7 @@ #define SECTOR_SIZE 512 #define READ_AHEAD_SIZE (256 * 1024) +#define CURL_CACHE_QUOTA 10 struct BDRVCURLState; @@ -90,6 +91,8 @@ typedef struct BDRVCURLState { QEMUTimer *timer; /* List of data cache ordered by access, freed from tail */ QLIST_HEAD(, CURLDataCache) cache; + /* Threshold to release unused cache when cache list is longer than it */ + int cache_quota; /* Whether http server accept range in header */ bool accept_range; } BDRVCURLState; @@ -526,6 +529,8 @@ static int curl_open(BlockDriverState *bs, QDict *options, int flags) curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running); qemu_opts_del(opts); + s->cache_quota = CURL_CACHE_QUOTA; + return 0; out: @@ -595,6 +600,27 @@ static void curl_readv_bh_cb(void *p) cache->data_len = aio_bytes + s->readahead_size; cache->write_pos = 0; cache->data = g_malloc(cache->data_len); + /* Try to release some cache */ + while (0 && s->cache_quota <= 0) { + CURLDataCache *p; + CURLDataCache *q = NULL; + assert(!QLIST_EMPTY(&s->cache)); + for (p = QLIST_FIRST(&s->cache); + p; p = QLIST_NEXT(p, next)) { + if (p->use_count == 0) { + q = p; + } + } + if (!q) { + break; + } + QLIST_REMOVE(q, next); + g_free(q->data); + q->data = NULL; + g_free(q); + q = NULL; + s->cache_quota++; + } QLIST_INSERT_HEAD(&s->acbs, acb, next); snprintf(state->range, sizeof(state->range) - 1, "%zd-%zd", cache->base_pos, @@ -605,6 +631,7 @@ static void curl_readv_bh_cb(void *p) QLIST_INSERT_HEAD(&s->cache, cache, next); state->cache = cache; cache->use_count++; + s->cache_quota--; curl_multi_add_handle(s->multi, state->curl); /* kick off curl to start the action */ curl_multi_socket_action(s->multi, 0, CURL_SOCKET_TIMEOUT, &running);
Introduce a cache quota: BDRVCURLState.cache_quota. When adding new CURLDataCache to BDRVCURLState, if number of existing CURLDataCache is larger than CURL_CACHE_QUOTA, try to release some first to limit the in memory cache size. A least used entry is selected for releasing. Signed-off-by: Fam Zheng <famz@redhat.com> --- block/curl.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+)