Messages in this thread | | | Date | Wed, 23 Mar 2016 08:34:27 +1100 | From | Dave Chinner <> | Subject | Re: [PATCH 2/6] writeback: wb_start_writeback() should use WB_SYNC_ALL for WB_REASON_SYNC |
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On Tue, Mar 22, 2016 at 11:55:16AM -0600, Jens Axboe wrote: > If you call sync, the initial call to wakeup_flusher_threads() ends up > calling wb_start_writeback() with reason=WB_REASON_SYNC, but > wb_start_writeback() always uses WB_SYNC_NONE as the writeback mode. > Ensure that we use WB_SYNC_ALL for a sync operation.
This seems wrong to me. We want background write to happen as quickly as possible and /not block/ when we first kick sync.
The latter blocking passes of sync use WB_SYNC_ALL to ensure that we block waiting for all remaining IO to be issued and waited on, but the background writeback doesn't need to do this.
Cheers,
Dave. -- Dave Chinner david@fromorbit.com
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