On Sun, Nov 07 2004, Andrew Morton wrote: > Neil Brown <neilb@xxxxxxxxxxxxxxx> wrote: > > > > On Friday November 5, axboe@xxxxxxx wrote: > > > On Thu, Nov 04 2004, Jens Axboe wrote: > > > > On Wed, Nov 03 2004, Andrew Morton wrote: > > > > > NeilBrown <neilb@xxxxxxxxxxxxxxx> wrote: > > > > > > > > > > > > As the unplug timer can potentially fire at any time, and > > > > > > and it access data that is released by the md ->stop function, > > > > > > we need to del_timer_sync before releasing that data. > > > > > > > > > > I don't think I saw an update to this patch so I just knocked up the below > > > > > simple conversion. If anyone can think up a nice description of what > > > > > blk_sync_queue() should do, it would be appreciated ;) > > > > > > > > I don't see much merrit in this patch, you have to prevent new requests > > > > from setting it off again. Basically, from my understanding, Neil needs > > > > a way to atomically kill the timer and the unplug function. Correct? > > > > > > Actually, with the online io scheduler switching we have a way to do > > > this already: > > > > > > blk_wait_queue_drained(q, 1); > > > blk_sync_queue(q); > > > > > > > I couldn't find blk_sync_queue in 2.6.10-rc1-mm2 .... > > I added it in -mm3 to replace all the open-coded del_timer_sync()s. > > ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.10-rc1/2.6.10-rc1-mm3/broken-out/md-delete-unplug-timer-before-shutting-down-md-array-cleanup.patch I seem to be missing Neils reply, this is the first I see of it. Strange. > > > > > > Would this work for you, Neil? > > > > I need it to do: > > del_timer_sync(&q->unplug_timer); > > kblockd_flush(); blk_sync_queue() should do both. I'm unsure of whether we should wrap blk_wait_queue_drained() and that into a seperate helper. There needs to be an unfreeze as well, of course. Perhaps blk_freeze_queue() and blk_unfreeze_queue()? -- Jens Axboe - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
