| Message ID | 21b8a171-ea95-9eef-8c68-8cee98c7367@redhat.com (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Delegated to: | Mike Snitzer |
| Headers | show |
| Series | [v2] dm-io: don't warn if flush takes too long time | expand |
On 2024/04/16 0:23, Mikulas Patocka wrote: >>> @@ -119,4 +120,16 @@ extern void complete(struct completion * >>> extern void complete_on_current_cpu(struct completion *x); >>> extern void complete_all(struct completion *); >>> >>> +static inline void blk_wait_io(struct completion *done) >> >> Since you move this function outside of the block layer, the "blk_" prefix seems >> out of place. What about renaming this to something like >> "wait_for_completion_blk_io()", or to make it clear that it is not the same as >> wait_for_completion_io(), may be "wait_for_completion_long_io()" ? > > Yes. Here I'm sending a second patch that renames this function to > wait_for_completion_long_io. This looks good to me, but you sent this new version as a reply. Please post a properly formatted new patch. And since you are touching the block layer, this needs to be sent to linux-block and Jens as well. > > Mikulas > > > > From: Mikulas Patocka <mpatocka@redhat.com> > > There was reported hang warning when using dm-integrity on the top of loop > device on XFS on a rotational disk. The warning was triggered because > flush on the loop device was too slow. > > There's no easy way to reduce the latency, so I made a patch that shuts > the warning up. > > There's already a function blk_wait_io that avoids the hung task warning. > This commit moves this function from block/blk.h to > include/linux/completion.h, renames it to wait_for_completion_long_io > (because it is not dependent on the block layer at all) and uses it in > dm-io instead of wait_for_completion_io. > > [ 1352.586981] INFO: task kworker/1:2:14820 blocked for more than 120 seconds. > [ 1352.593951] Not tainted 4.18.0-552.el8_10.x86_64 #1 > [ 1352.599358] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > [ 1352.607202] Call Trace: > [ 1352.609670] __schedule+0x2d1/0x870 > [ 1352.613173] ? update_load_avg+0x7e/0x710 > [ 1352.617193] ? update_load_avg+0x7e/0x710 > [ 1352.621214] schedule+0x55/0xf0 > [ 1352.624371] schedule_timeout+0x281/0x320 > [ 1352.628393] ? __schedule+0x2d9/0x870 > [ 1352.632065] io_schedule_timeout+0x19/0x40 > [ 1352.636176] wait_for_completion_io+0x96/0x100 > [ 1352.640639] sync_io+0xcc/0x120 [dm_mod] > [ 1352.644592] dm_io+0x209/0x230 [dm_mod] > [ 1352.648436] ? bit_wait_timeout+0xa0/0xa0 > [ 1352.652461] ? vm_next_page+0x20/0x20 [dm_mod] > [ 1352.656924] ? km_get_page+0x60/0x60 [dm_mod] > [ 1352.661298] dm_bufio_issue_flush+0xa0/0xd0 [dm_bufio] > [ 1352.666448] dm_bufio_write_dirty_buffers+0x1a0/0x1e0 [dm_bufio] > [ 1352.672462] dm_integrity_flush_buffers+0x32/0x140 [dm_integrity] > [ 1352.678567] ? lock_timer_base+0x67/0x90 > [ 1352.682505] ? __timer_delete.part.36+0x5c/0x90 > [ 1352.687050] integrity_commit+0x31a/0x330 [dm_integrity] > [ 1352.692368] ? __switch_to+0x10c/0x430 > [ 1352.696131] process_one_work+0x1d3/0x390 > [ 1352.700152] ? process_one_work+0x390/0x390 > [ 1352.704348] worker_thread+0x30/0x390 > [ 1352.708019] ? process_one_work+0x390/0x390 > [ 1352.712214] kthread+0x134/0x150 > [ 1352.715459] ? set_kthread_struct+0x50/0x50 > [ 1352.719659] ret_from_fork+0x1f/0x40 > > Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> > > --- > block/bio.c | 2 +- > block/blk-mq.c | 2 +- > block/blk.h | 12 ------------ > drivers/md/dm-io.c | 2 +- > include/linux/completion.h | 17 +++++++++++++++++ > 5 files changed, 20 insertions(+), 15 deletions(-) > > Index: linux-2.6/block/blk.h > =================================================================== > --- linux-2.6.orig/block/blk.h 2024-04-15 15:54:22.000000000 +0200 > +++ linux-2.6/block/blk.h 2024-04-15 15:54:21.000000000 +0200 > @@ -72,18 +72,6 @@ static inline int bio_queue_enter(struct > return __bio_queue_enter(q, bio); > } > > -static inline void blk_wait_io(struct completion *done) > -{ > - /* Prevent hang_check timer from firing at us during very long I/O */ > - unsigned long timeout = sysctl_hung_task_timeout_secs * HZ / 2; > - > - if (timeout) > - while (!wait_for_completion_io_timeout(done, timeout)) > - ; > - else > - wait_for_completion_io(done); > -} > - > #define BIO_INLINE_VECS 4 > struct bio_vec *bvec_alloc(mempool_t *pool, unsigned short *nr_vecs, > gfp_t gfp_mask); > Index: linux-2.6/drivers/md/dm-io.c > =================================================================== > --- linux-2.6.orig/drivers/md/dm-io.c 2024-04-15 15:54:22.000000000 +0200 > +++ linux-2.6/drivers/md/dm-io.c 2024-04-15 15:54:21.000000000 +0200 > @@ -450,7 +450,7 @@ static int sync_io(struct dm_io_client * > > dispatch_io(opf, num_regions, where, dp, io, 1, ioprio); > > - wait_for_completion_io(&sio.wait); > + wait_for_completion_long_io(&sio.wait); > > if (error_bits) > *error_bits = sio.error_bits; > Index: linux-2.6/include/linux/completion.h > =================================================================== > --- linux-2.6.orig/include/linux/completion.h 2024-04-15 15:54:22.000000000 +0200 > +++ linux-2.6/include/linux/completion.h 2024-04-15 15:57:14.000000000 +0200 > @@ -10,6 +10,7 @@ > */ > > #include <linux/swait.h> > +#include <linux/sched/sysctl.h> > > /* > * struct completion - structure used to maintain state for a "completion" > @@ -119,4 +120,20 @@ extern void complete(struct completion * > extern void complete_on_current_cpu(struct completion *x); > extern void complete_all(struct completion *); > > +/** > + * wait_for_completion_long_io - this is like wait_for_completion_io, > + * but it doesn't warn if the wait takes too long. > + */ > +static inline void wait_for_completion_long_io(struct completion *done) > +{ > + /* Prevent hang_check timer from firing at us during very long I/O */ > + unsigned long timeout = sysctl_hung_task_timeout_secs * HZ / 2; > + > + if (timeout) > + while (!wait_for_completion_io_timeout(done, timeout)) > + ; > + else > + wait_for_completion_io(done); > +} > + > #endif > Index: linux-2.6/block/bio.c > =================================================================== > --- linux-2.6.orig/block/bio.c 2024-03-30 20:07:03.000000000 +0100 > +++ linux-2.6/block/bio.c 2024-04-15 15:55:13.000000000 +0200 > @@ -1378,7 +1378,7 @@ int submit_bio_wait(struct bio *bio) > bio->bi_end_io = submit_bio_wait_endio; > bio->bi_opf |= REQ_SYNC; > submit_bio(bio); > - blk_wait_io(&done); > + wait_for_completion_long_io(&done); > > return blk_status_to_errno(bio->bi_status); > } > Index: linux-2.6/block/blk-mq.c > =================================================================== > --- linux-2.6.orig/block/blk-mq.c 2024-03-30 20:07:03.000000000 +0100 > +++ linux-2.6/block/blk-mq.c 2024-04-15 15:55:05.000000000 +0200 > @@ -1407,7 +1407,7 @@ blk_status_t blk_execute_rq(struct reque > if (blk_rq_is_poll(rq)) > blk_rq_poll_completion(rq, &wait.done); > else > - blk_wait_io(&wait.done); > + wait_for_completion_long_io(&wait.done); > > return wait.ret; > } >
On Wed, 17 Apr 2024, Damien Le Moal wrote: > On 2024/04/16 0:23, Mikulas Patocka wrote: > >>> @@ -119,4 +120,16 @@ extern void complete(struct completion * > >>> extern void complete_on_current_cpu(struct completion *x); > >>> extern void complete_all(struct completion *); > >>> > >>> +static inline void blk_wait_io(struct completion *done) > >> > >> Since you move this function outside of the block layer, the "blk_" prefix seems > >> out of place. What about renaming this to something like > >> "wait_for_completion_blk_io()", or to make it clear that it is not the same as > >> wait_for_completion_io(), may be "wait_for_completion_long_io()" ? > > > > Yes. Here I'm sending a second patch that renames this function to > > wait_for_completion_long_io. > > This looks good to me, but you sent this new version as a reply. Please post a > properly formatted new patch. And since you are touching the block layer, this > needs to be sent to linux-block and Jens as well. OK. I've resent it. Mikulas
Index: linux-2.6/block/blk.h =================================================================== --- linux-2.6.orig/block/blk.h 2024-04-15 15:54:22.000000000 +0200 +++ linux-2.6/block/blk.h 2024-04-15 15:54:21.000000000 +0200 @@ -72,18 +72,6 @@ static inline int bio_queue_enter(struct return __bio_queue_enter(q, bio); } -static inline void blk_wait_io(struct completion *done) -{ - /* Prevent hang_check timer from firing at us during very long I/O */ - unsigned long timeout = sysctl_hung_task_timeout_secs * HZ / 2; - - if (timeout) - while (!wait_for_completion_io_timeout(done, timeout)) - ; - else - wait_for_completion_io(done); -} - #define BIO_INLINE_VECS 4 struct bio_vec *bvec_alloc(mempool_t *pool, unsigned short *nr_vecs, gfp_t gfp_mask); Index: linux-2.6/drivers/md/dm-io.c =================================================================== --- linux-2.6.orig/drivers/md/dm-io.c 2024-04-15 15:54:22.000000000 +0200 +++ linux-2.6/drivers/md/dm-io.c 2024-04-15 15:54:21.000000000 +0200 @@ -450,7 +450,7 @@ static int sync_io(struct dm_io_client * dispatch_io(opf, num_regions, where, dp, io, 1, ioprio); - wait_for_completion_io(&sio.wait); + wait_for_completion_long_io(&sio.wait); if (error_bits) *error_bits = sio.error_bits; Index: linux-2.6/include/linux/completion.h =================================================================== --- linux-2.6.orig/include/linux/completion.h 2024-04-15 15:54:22.000000000 +0200 +++ linux-2.6/include/linux/completion.h 2024-04-15 15:57:14.000000000 +0200 @@ -10,6 +10,7 @@ */ #include <linux/swait.h> +#include <linux/sched/sysctl.h> /* * struct completion - structure used to maintain state for a "completion" @@ -119,4 +120,20 @@ extern void complete(struct completion * extern void complete_on_current_cpu(struct completion *x); extern void complete_all(struct completion *); +/** + * wait_for_completion_long_io - this is like wait_for_completion_io, + * but it doesn't warn if the wait takes too long. + */ +static inline void wait_for_completion_long_io(struct completion *done) +{ + /* Prevent hang_check timer from firing at us during very long I/O */ + unsigned long timeout = sysctl_hung_task_timeout_secs * HZ / 2; + + if (timeout) + while (!wait_for_completion_io_timeout(done, timeout)) + ; + else + wait_for_completion_io(done); +} + #endif Index: linux-2.6/block/bio.c =================================================================== --- linux-2.6.orig/block/bio.c 2024-03-30 20:07:03.000000000 +0100 +++ linux-2.6/block/bio.c 2024-04-15 15:55:13.000000000 +0200 @@ -1378,7 +1378,7 @@ int submit_bio_wait(struct bio *bio) bio->bi_end_io = submit_bio_wait_endio; bio->bi_opf |= REQ_SYNC; submit_bio(bio); - blk_wait_io(&done); + wait_for_completion_long_io(&done); return blk_status_to_errno(bio->bi_status); } Index: linux-2.6/block/blk-mq.c =================================================================== --- linux-2.6.orig/block/blk-mq.c 2024-03-30 20:07:03.000000000 +0100 +++ linux-2.6/block/blk-mq.c 2024-04-15 15:55:05.000000000 +0200 @@ -1407,7 +1407,7 @@ blk_status_t blk_execute_rq(struct reque if (blk_rq_is_poll(rq)) blk_rq_poll_completion(rq, &wait.done); else - blk_wait_io(&wait.done); + wait_for_completion_long_io(&wait.done); return wait.ret; }