From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49575) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dACoa-0000c1-FH for qemu-devel@nongnu.org; Mon, 15 May 2017 06:01:25 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dACoZ-0005un-Hg for qemu-devel@nongnu.org; Mon, 15 May 2017 06:01:20 -0400 From: Paolo Bonzini Date: Mon, 15 May 2017 12:00:59 +0200 Message-Id: <20170515100059.15795-8-pbonzini@redhat.com> In-Reply-To: <20170515100059.15795-1-pbonzini@redhat.com> References: <20170515100059.15795-1-pbonzini@redhat.com> Subject: [Qemu-devel] [PATCH v3 7/7] curl: do not do aio_poll when waiting for a free CURLState List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: jcody@redhat.com, rjones@redhat.com, qemu-block@nongnu.org Instead, put the CURLAIOCB on a wait list and yield; curl_clean_state will wake the corresponding coroutine. Because of CURL's callback-based structure, we cannot easily convert everything to CoMutex/CoQueue; keeping the QemuMutex is simpler. However, CoQueue is a simple wrapper around a linked list, so we can easily use QSIMPLEQ and open-code a CoQueue, protected by the BDRVCURLState QemuMutex instead of a CoMutex. Reviewed-by: Jeff Cody Signed-off-by: Paolo Bonzini --- block/curl.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/block/curl.c b/block/curl.c index 86a4a73834..630c6e5187 100644 --- a/block/curl.c +++ b/block/curl.c @@ -98,6 +98,8 @@ typedef struct CURLAIOCB { size_t start; size_t end; + + QSIMPLEQ_ENTRY(CURLAIOCB) next; } CURLAIOCB; typedef struct CURLSocket { @@ -133,6 +135,7 @@ typedef struct BDRVCURLState { bool accept_range; AioContext *aio_context; QemuMutex mutex; + QSIMPLEQ_HEAD(, CURLAIOCB) free_state_waitq; char *username; char *password; char *proxyusername; @@ -532,6 +535,7 @@ static int curl_init_state(BDRVCURLState *s, CURLState *state) /* Called with s->mutex held. */ static void curl_clean_state(CURLState *s) { + CURLAIOCB *next; int j; for (j=0; j < CURL_NUM_ACB; j++) { assert(!s->acb[j]); @@ -548,6 +552,14 @@ static void curl_clean_state(CURLState *s) } s->in_use = 0; + + next = QSIMPLEQ_FIRST(&s->s->free_state_waitq); + if (next) { + QSIMPLEQ_REMOVE_HEAD(&s->s->free_state_waitq, next); + qemu_mutex_unlock(&s->s->mutex); + aio_co_wake(next->co); + qemu_mutex_lock(&s->s->mutex); + } } static void curl_parse_filename(const char *filename, QDict *options, @@ -744,6 +756,7 @@ static int curl_open(BlockDriverState *bs, QDict *options, int flags, } DPRINTF("CURL: Opening %s\n", file); + QSIMPLEQ_INIT(&s->free_state_waitq); s->aio_context = bdrv_get_aio_context(bs); s->url = g_strdup(file); qemu_mutex_lock(&s->mutex); @@ -844,8 +857,9 @@ static void curl_setup_preadv(BlockDriverState *bs, CURLAIOCB *acb) if (state) { break; } + QSIMPLEQ_INSERT_TAIL(&s->free_state_waitq, acb, next); qemu_mutex_unlock(&s->mutex); - aio_poll(bdrv_get_aio_context(bs), true); + qemu_coroutine_yield(); qemu_mutex_lock(&s->mutex); } -- 2.12.2