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[Qemu-devel] [PATCH 08/18] throttle-groups: do not use qemu_co_enter_nex
From: |
Paolo Bonzini |
Subject: |
[Qemu-devel] [PATCH 08/18] throttle-groups: do not use qemu_co_enter_next |
Date: |
Thu, 11 May 2017 16:41:58 +0200 |
Prepare for removing this function; always restart throttled requests
from coroutine context. This will matter when restarting throttled
requests will have to acquire a CoMutex.
Signed-off-by: Paolo Bonzini <address@hidden>
---
v1->v2: heavily simplified thanks to previous patch [Stefan]
add coroutine_fn as needed [Stefan]
block/throttle-groups.c | 42 +++++++++++++++++++++++++++++++++++++-----
1 file changed, 37 insertions(+), 5 deletions(-)
diff --git a/block/throttle-groups.c b/block/throttle-groups.c
index 85169ecfb0..8bf1031efa 100644
--- a/block/throttle-groups.c
+++ b/block/throttle-groups.c
@@ -260,6 +260,20 @@ static bool throttle_group_schedule_timer(BlockBackend
*blk, bool is_write)
return must_wait;
}
+/* Start the next pending I/O request for a BlockBackend. Return whether
+ * any request was actually pending.
+ *
+ * @blk: the current BlockBackend
+ * @is_write: the type of operation (read/write)
+ */
+static bool coroutine_fn throttle_group_co_restart_queue(BlockBackend *blk,
+ bool is_write)
+{
+ BlockBackendPublic *blkp = blk_get_public(blk);
+
+ return qemu_co_queue_next(&blkp->throttled_reqs[is_write]);
+}
+
/* Look for the next pending I/O request and schedule it.
*
* This assumes that tg->lock is held.
@@ -287,7 +301,7 @@ static void schedule_next_request(BlockBackend *blk, bool
is_write)
if (!must_wait) {
/* Give preference to requests from the current blk */
if (qemu_in_coroutine() &&
- qemu_co_queue_next(&blkp->throttled_reqs[is_write])) {
+ throttle_group_co_restart_queue(blk, is_write)) {
token = blk;
} else {
ThrottleTimers *tt = &blk_get_public(token)->throttle_timers;
@@ -340,15 +354,21 @@ void coroutine_fn
throttle_group_co_io_limits_intercept(BlockBackend *blk,
qemu_mutex_unlock(&tg->lock);
}
-static void throttle_group_restart_queue(BlockBackend *blk, bool is_write)
+typedef struct {
+ BlockBackend *blk;
+ bool is_write;
+} RestartData;
+
+static void coroutine_fn throttle_group_restart_queue_entry(void *opaque)
{
+ RestartData *data = opaque;
+ BlockBackend *blk = data->blk;
+ bool is_write = data->is_write;
BlockBackendPublic *blkp = blk_get_public(blk);
ThrottleGroup *tg = container_of(blkp->throttle_state, ThrottleGroup, ts);
bool empty_queue;
- aio_context_acquire(blk_get_aio_context(blk));
- empty_queue = !qemu_co_enter_next(&blkp->throttled_reqs[is_write]);
- aio_context_release(blk_get_aio_context(blk));
+ empty_queue = !throttle_group_co_restart_queue(blk, is_write);
/* If the request queue was empty then we have to take care of
* scheduling the next one */
@@ -359,6 +379,18 @@ static void throttle_group_restart_queue(BlockBackend
*blk, bool is_write)
}
}
+static void throttle_group_restart_queue(BlockBackend *blk, bool is_write)
+{
+ Coroutine *co;
+ RestartData rd = {
+ .blk = blk,
+ .is_write = is_write
+ };
+
+ co = qemu_coroutine_create(throttle_group_restart_queue_entry, &rd);
+ aio_co_enter(blk_get_aio_context(blk), co);
+}
+
void throttle_group_restart_blk(BlockBackend *blk)
{
BlockBackendPublic *blkp = blk_get_public(blk);
--
2.12.2
- [Qemu-devel] [PATCH 04/18] block: access serialising_in_flight with atomic ops, (continued)
- [Qemu-devel] [PATCH 04/18] block: access serialising_in_flight with atomic ops, Paolo Bonzini, 2017/05/11
- [Qemu-devel] [PATCH 03/18] block: access io_limits_disabled with atomic ops, Paolo Bonzini, 2017/05/11
- [Qemu-devel] [PATCH 02/18] block: access quiesce_counter with atomic ops, Paolo Bonzini, 2017/05/11
- [Qemu-devel] [PATCH 05/18] block: access wakeup with atomic ops, Paolo Bonzini, 2017/05/11
- [Qemu-devel] [PATCH 09/18] throttle-groups: protect throttled requests with a CoMutex, Paolo Bonzini, 2017/05/11
- [Qemu-devel] [PATCH 06/18] block: access io_plugged with atomic ops, Paolo Bonzini, 2017/05/11
- [Qemu-devel] [PATCH 08/18] throttle-groups: do not use qemu_co_enter_next,
Paolo Bonzini <=
- [Qemu-devel] [PATCH 07/18] throttle-groups: only start one coroutine from drained_begin, Paolo Bonzini, 2017/05/11
- [Qemu-devel] [PATCH 10/18] util: add stats64 module, Paolo Bonzini, 2017/05/11
- [Qemu-devel] [PATCH 13/18] block: protect tracked_requests and flush_queue with reqs_lock, Paolo Bonzini, 2017/05/11
- [Qemu-devel] [PATCH 11/18] block: use Stat64 for wr_highest_offset, Paolo Bonzini, 2017/05/11