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[Qemu-devel] [PATCH v3 13/15] blockjob: add pause points
From: |
Stefan Hajnoczi |
Subject: |
[Qemu-devel] [PATCH v3 13/15] blockjob: add pause points |
Date: |
Mon, 13 Jun 2016 18:05:33 +0100 |
Block jobs are coroutines that usually perform I/O but sometimes also
sleep or yield. Currently only sleeping or yielded block jobs can be
paused. This means jobs that do not sleep or yield (using
block_job_yield()) are unaffected by block_job_pause().
Add block_job_pause_point() so that block jobs can mark quiescent points
that are suitable for pausing. This solves the problem that is can take
a block job a long time to pause if it is performing a long series of
I/O operations.
Signed-off-by: Stefan Hajnoczi <address@hidden>
---
blockjob.c | 7 +++++++
include/block/blockjob.h | 12 ++++++++++++
2 files changed, 19 insertions(+)
diff --git a/blockjob.c b/blockjob.c
index 463bccf..b810d73 100644
--- a/blockjob.c
+++ b/blockjob.c
@@ -247,6 +247,13 @@ void block_job_complete(BlockJob *job, Error **errp)
job->driver->complete(job, errp);
}
+void block_job_pause_point(BlockJob *job)
+{
+ if (block_job_is_paused(job)) {
+ block_job_yield(job);
+ }
+}
+
void block_job_pause(BlockJob *job)
{
job->pause_count++;
diff --git a/include/block/blockjob.h b/include/block/blockjob.h
index 00ac418..f83a4f0 100644
--- a/include/block/blockjob.h
+++ b/include/block/blockjob.h
@@ -299,6 +299,18 @@ bool block_job_is_cancelled(BlockJob *job);
BlockJobInfo *block_job_query(BlockJob *job);
/**
+ * block_job_pause_point:
+ * @job: The job that is ready to pause.
+ *
+ * Pause now if block_job_pause() has been called. Block jobs that perform
+ * lots of I/O must call this between requests so that the job can be paused.
+ *
+ * There must be no I/O in flight when this function is called. There must be
+ * no I/O or event loop activity until after this function returns.
+ */
+void coroutine_fn block_job_pause_point(BlockJob *job);
+
+/**
* block_job_pause:
* @job: The job to be paused.
*
--
2.5.5
- [Qemu-devel] [PATCH v3 03/15] cpu-exec: Rename cpu_resume_from_signal() to cpu_loop_exit_noexc(), (continued)
- [Qemu-devel] [PATCH v3 03/15] cpu-exec: Rename cpu_resume_from_signal() to cpu_loop_exit_noexc(), Stefan Hajnoczi, 2016/06/13
- [Qemu-devel] [PATCH v3 04/15] user-exec: Don't reextract sigmask from usercontext pointer, Stefan Hajnoczi, 2016/06/13
- [Qemu-devel] [PATCH v3 05/15] target-i386: Add comment about do_interrupt_user() next_eip argument, Stefan Hajnoczi, 2016/06/13
- [Qemu-devel] [PATCH v3 06/15] target-i386: Move user-mode exception actions out of user-exec.c, Stefan Hajnoczi, 2016/06/13
- [Qemu-devel] [PATCH v3 08/15] ui: fix regression in printing VNC host/port on startup, Stefan Hajnoczi, 2016/06/13
- [Qemu-devel] [PATCH v3 07/15] vnc: drop unused depth arg for set_pixel_format, Stefan Hajnoczi, 2016/06/13
- [Qemu-devel] [PATCH v3 09/15] gtk: fix vte version check, Stefan Hajnoczi, 2016/06/13
- [Qemu-devel] [PATCH v3 10/15] ui/console-gl: Add support for big endian display surfaces, Stefan Hajnoczi, 2016/06/13
- [Qemu-devel] [PATCH v3 12/15] blockjob: move iostatus reset out of block_job_enter(), Stefan Hajnoczi, 2016/06/13
- [Qemu-devel] [PATCH v3 11/15] console: ignore ui_info updates which don't actually update something, Stefan Hajnoczi, 2016/06/13
- [Qemu-devel] [PATCH v3 13/15] blockjob: add pause points,
Stefan Hajnoczi <=
- [Qemu-devel] [PATCH v3 14/15] blockjob: add AioContext attach/detach callbacks, Stefan Hajnoczi, 2016/06/13
- [Qemu-devel] [PATCH v3 15/15] mirror: follow AioContext change gracefully, Stefan Hajnoczi, 2016/06/13
- Re: [Qemu-devel] [PATCH v3 00/15] mirror: follow AioContext change gracefully, Stefan Hajnoczi, 2016/06/13
- Re: [Qemu-devel] [PATCH v3 00/15] mirror: follow AioContext change gracefully, Fam Zheng, 2016/06/14