mirror of https://github.com/xemu-project/xemu.git
fc9c0a9c4b
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 it can take a block job a long time to pause if it is performing a long series of I/O operations. Transitioning to paused state involves a .pause()/.resume() callback. These callbacks are used to ensure that I/O and event loop activity has ceased while the job is at a pause point. Note that this patch introduces a stricter pause state than previously. The job->busy flag was incorrectly documented as a quiescent state without I/O pending. This is violated by any job that has I/O pending across sleep or block_job_yield(), like the mirror block job. [Add missing block_job_should_pause() check to avoid deadlock after job->driver->pause() in block_job_pause_point(). --Stefan] Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Message-id: 1466096189-6477-4-git-send-email-stefanha@redhat.com |
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| .. | ||
| accounting.h | ||
| aio.h | ||
| block.h | ||
| block_int.h | ||
| blockjob.h | ||
| dirty-bitmap.h | ||
| nbd.h | ||
| qapi.h | ||
| scsi.h | ||
| snapshot.h | ||
| thread-pool.h | ||
| throttle-groups.h | ||
| write-threshold.h | ||