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[PATCH v2 3/6] block: convert bdrv_graph_wrlock() to AIO_WAIT_WHILE_UNLO
From: |
Stefan Hajnoczi |
Subject: |
[PATCH v2 3/6] block: convert bdrv_graph_wrlock() to AIO_WAIT_WHILE_UNLOCKED() |
Date: |
Thu, 9 Mar 2023 14:08:52 -0500 |
The following conversion is safe and does not change behavior:
GLOBAL_STATE_CODE();
...
- AIO_WAIT_WHILE(qemu_get_aio_context(), ...);
+ AIO_WAIT_WHILE_UNLOCKED(NULL, ...);
Since we're in GLOBAL_STATE_CODE(), qemu_get_aio_context() is our home
thread's AioContext. Thus AIO_WAIT_WHILE() does not unlock the
AioContext:
if (ctx_ && in_aio_context_home_thread(ctx_)) { \
while ((cond)) { \
aio_poll(ctx_, true); \
waited_ = true; \
} \
And that means AIO_WAIT_WHILE_UNLOCKED(NULL, ...) can be substituted.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Tested-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
block/graph-lock.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/block/graph-lock.c b/block/graph-lock.c
index 454c31e691..639526608f 100644
--- a/block/graph-lock.c
+++ b/block/graph-lock.c
@@ -127,7 +127,7 @@ void bdrv_graph_wrlock(void)
* reader lock.
*/
qatomic_set(&has_writer, 0);
- AIO_WAIT_WHILE(qemu_get_aio_context(), reader_count() >= 1);
+ AIO_WAIT_WHILE_UNLOCKED(NULL, reader_count() >= 1);
qatomic_set(&has_writer, 1);
/*
--
2.39.2
- [PATCH v2 0/6] block: switch to AIO_WAIT_WHILE_UNLOCKED() where possible, Stefan Hajnoczi, 2023/03/09
- [PATCH v2 2/6] block: convert blk_exp_close_all_type() to AIO_WAIT_WHILE_UNLOCKED(), Stefan Hajnoczi, 2023/03/09
- [PATCH v2 1/6] block: don't acquire AioContext lock in bdrv_drain_all(), Stefan Hajnoczi, 2023/03/09
- [PATCH v2 3/6] block: convert bdrv_graph_wrlock() to AIO_WAIT_WHILE_UNLOCKED(),
Stefan Hajnoczi <=
- [PATCH v2 4/6] block: convert bdrv_drain_all_begin() to AIO_WAIT_WHILE_UNLOCKED(), Stefan Hajnoczi, 2023/03/09
- [PATCH v2 5/6] hmp: convert handle_hmp_command() to AIO_WAIT_WHILE_UNLOCKED(), Stefan Hajnoczi, 2023/03/09
- [PATCH v2 6/6] monitor: convert monitor_cleanup() to AIO_WAIT_WHILE_UNLOCKED(), Stefan Hajnoczi, 2023/03/09
- Re: [PATCH v2 0/6] block: switch to AIO_WAIT_WHILE_UNLOCKED() where possible, Kevin Wolf, 2023/03/14