| Message ID | 20210806111857.488705-4-damien.lemoal@wdc.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | IO priority fixes and improvements | expand |
On 8/6/21 1:18 PM, Damien Le Moal wrote: > The BFQ scheduler and ioprio_check_cap() both assume that the RT > priority class (IOPRIO_CLASS_RT) can have up to 8 different priority > levels. This is controlled using the macro IOPRIO_BE_NR, which is badly > named as the number of levels also applies to the RT class. > > Rename IOPRIO_BE_NR to the class independent IOPRIO_NR_LEVELS to make > things clear. > > Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> > --- > block/bfq-iosched.c | 8 ++++---- > block/bfq-iosched.h | 4 ++-- > block/bfq-wf2q.c | 6 +++--- > block/ioprio.c | 3 +-- > fs/f2fs/sysfs.c | 2 +- > include/uapi/linux/ioprio.h | 4 ++-- > 6 files changed, 13 insertions(+), 14 deletions(-) > Reviewed-by: Hannes Reinecke <hare@suse.de> Cheers, Hannes
On 8/6/21 5:18 AM, Damien Le Moal wrote: > diff --git a/include/uapi/linux/ioprio.h b/include/uapi/linux/ioprio.h > index abc40965aa96..99d37d4807b8 100644 > --- a/include/uapi/linux/ioprio.h > +++ b/include/uapi/linux/ioprio.h > @@ -31,9 +31,9 @@ enum { > }; > > /* > - * 8 best effort priority levels are supported > + * The RT and BE priority classes both support up to 8 priority levels. > */ > -#define IOPRIO_BE_NR 8 > +#define IOPRIO_NR_LEVELS 8 That might not be a good idea, if an application already uses IOPRIO_BE_NR...
On 2021/08/08 1:16, Jens Axboe wrote: > On 8/6/21 5:18 AM, Damien Le Moal wrote: >> diff --git a/include/uapi/linux/ioprio.h b/include/uapi/linux/ioprio.h >> index abc40965aa96..99d37d4807b8 100644 >> --- a/include/uapi/linux/ioprio.h >> +++ b/include/uapi/linux/ioprio.h >> @@ -31,9 +31,9 @@ enum { >> }; >> >> /* >> - * 8 best effort priority levels are supported >> + * The RT and BE priority classes both support up to 8 priority levels. >> */ >> -#define IOPRIO_BE_NR 8 >> +#define IOPRIO_NR_LEVELS 8 > > That might not be a good idea, if an application already uses > IOPRIO_BE_NR... Hmmm. include/uapi/linux/ioprio.h is being introduced with kernel 5.15. These definition are not UAPI level right now. What about something like this: #define IOPRIO_NR_LEVELS 8 #define IOPRIO_BE_NR IOPRIO_NR_LEVELS To keep IOPRIO_BE_NR ? OR, Keep IOPRIO_BE_NR as is in include/uapi/linux/ioprio.h and add #define IOPRIO_NR_LEVELS IOPRIO_BE_NR in include/linux/ioprio.h ? Both would still allow doing some cleanup kernel side. Or I can just drop this patch too.
On Sat, Aug 07, 2021 at 10:16:39AM -0600, Jens Axboe wrote: > > /* > > - * 8 best effort priority levels are supported > > + * The RT and BE priority classes both support up to 8 priority levels. > > */ > > -#define IOPRIO_BE_NR 8 > > +#define IOPRIO_NR_LEVELS 8 > > That might not be a good idea, if an application already uses > IOPRIO_BE_NR... The constant has not actually been exposed in a uapi header in any released kernel, so if there is a time to rename it it is now.
diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index 1f38d75524ae..d5824cab34d7 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -2505,7 +2505,7 @@ void bfq_end_wr_async_queues(struct bfq_data *bfqd, int i, j; for (i = 0; i < 2; i++) - for (j = 0; j < IOPRIO_BE_NR; j++) + for (j = 0; j < IOPRIO_NR_LEVELS; j++) if (bfqg->async_bfqq[i][j]) bfq_bfqq_end_wr(bfqg->async_bfqq[i][j]); if (bfqg->async_idle_bfqq) @@ -5290,10 +5290,10 @@ bfq_set_next_ioprio_data(struct bfq_queue *bfqq, struct bfq_io_cq *bic) break; } - if (bfqq->new_ioprio >= IOPRIO_BE_NR) { + if (bfqq->new_ioprio >= IOPRIO_NR_LEVELS) { pr_crit("bfq_set_next_ioprio_data: new_ioprio %d\n", bfqq->new_ioprio); - bfqq->new_ioprio = IOPRIO_BE_NR - 1; + bfqq->new_ioprio = IOPRIO_NR_LEVELS - 1; } bfqq->entity.new_weight = bfq_ioprio_to_weight(bfqq->new_ioprio); @@ -6822,7 +6822,7 @@ void bfq_put_async_queues(struct bfq_data *bfqd, struct bfq_group *bfqg) int i, j; for (i = 0; i < 2; i++) - for (j = 0; j < IOPRIO_BE_NR; j++) + for (j = 0; j < IOPRIO_NR_LEVELS; j++) __bfq_put_async_bfqq(bfqd, &bfqg->async_bfqq[i][j]); __bfq_put_async_bfqq(bfqd, &bfqg->async_idle_bfqq); diff --git a/block/bfq-iosched.h b/block/bfq-iosched.h index 99c2a3cb081e..385e28a843d1 100644 --- a/block/bfq-iosched.h +++ b/block/bfq-iosched.h @@ -931,7 +931,7 @@ struct bfq_group { void *bfqd; - struct bfq_queue *async_bfqq[2][IOPRIO_BE_NR]; + struct bfq_queue *async_bfqq[2][IOPRIO_NR_LEVELS]; struct bfq_queue *async_idle_bfqq; struct bfq_entity *my_entity; @@ -948,7 +948,7 @@ struct bfq_group { struct bfq_entity entity; struct bfq_sched_data sched_data; - struct bfq_queue *async_bfqq[2][IOPRIO_BE_NR]; + struct bfq_queue *async_bfqq[2][IOPRIO_NR_LEVELS]; struct bfq_queue *async_idle_bfqq; struct rb_root rq_pos_tree; diff --git a/block/bfq-wf2q.c b/block/bfq-wf2q.c index 7a462df71f68..b74cc0da118e 100644 --- a/block/bfq-wf2q.c +++ b/block/bfq-wf2q.c @@ -505,7 +505,7 @@ static void bfq_active_insert(struct bfq_service_tree *st, */ unsigned short bfq_ioprio_to_weight(int ioprio) { - return (IOPRIO_BE_NR - ioprio) * BFQ_WEIGHT_CONVERSION_COEFF; + return (IOPRIO_NR_LEVELS - ioprio) * BFQ_WEIGHT_CONVERSION_COEFF; } /** @@ -514,12 +514,12 @@ unsigned short bfq_ioprio_to_weight(int ioprio) * * To preserve as much as possible the old only-ioprio user interface, * 0 is used as an escape ioprio value for weights (numerically) equal or - * larger than IOPRIO_BE_NR * BFQ_WEIGHT_CONVERSION_COEFF. + * larger than IOPRIO_NR_LEVELS * BFQ_WEIGHT_CONVERSION_COEFF. */ static unsigned short bfq_weight_to_ioprio(int weight) { return max_t(int, 0, - IOPRIO_BE_NR * BFQ_WEIGHT_CONVERSION_COEFF - weight); + IOPRIO_NR_LEVELS * BFQ_WEIGHT_CONVERSION_COEFF - weight); } static void bfq_get_entity(struct bfq_entity *entity) diff --git a/block/ioprio.c b/block/ioprio.c index bee628f9f1b2..ca6b136c5586 100644 --- a/block/ioprio.c +++ b/block/ioprio.c @@ -74,9 +74,8 @@ int ioprio_check_cap(int ioprio) fallthrough; /* rt has prio field too */ case IOPRIO_CLASS_BE: - if (data >= IOPRIO_BE_NR || data < 0) + if (data >= IOPRIO_NR_LEVELS || data < 0) return -EINVAL; - break; case IOPRIO_CLASS_IDLE: break; diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c index 6642246206bd..daad532a4e2b 100644 --- a/fs/f2fs/sysfs.c +++ b/fs/f2fs/sysfs.c @@ -378,7 +378,7 @@ static ssize_t __sbi_store(struct f2fs_attr *a, ret = kstrtol(name, 10, &data); if (ret) return ret; - if (data >= IOPRIO_BE_NR || data < 0) + if (data >= IOPRIO_NR_LEVELS || data < 0) return -EINVAL; cprc->ckpt_thread_ioprio = IOPRIO_PRIO_VALUE(class, data); diff --git a/include/uapi/linux/ioprio.h b/include/uapi/linux/ioprio.h index abc40965aa96..99d37d4807b8 100644 --- a/include/uapi/linux/ioprio.h +++ b/include/uapi/linux/ioprio.h @@ -31,9 +31,9 @@ enum { }; /* - * 8 best effort priority levels are supported + * The RT and BE priority classes both support up to 8 priority levels. */ -#define IOPRIO_BE_NR 8 +#define IOPRIO_NR_LEVELS 8 enum { IOPRIO_WHO_PROCESS = 1,
The BFQ scheduler and ioprio_check_cap() both assume that the RT priority class (IOPRIO_CLASS_RT) can have up to 8 different priority levels. This is controlled using the macro IOPRIO_BE_NR, which is badly named as the number of levels also applies to the RT class. Rename IOPRIO_BE_NR to the class independent IOPRIO_NR_LEVELS to make things clear. Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> --- block/bfq-iosched.c | 8 ++++---- block/bfq-iosched.h | 4 ++-- block/bfq-wf2q.c | 6 +++--- block/ioprio.c | 3 +-- fs/f2fs/sysfs.c | 2 +- include/uapi/linux/ioprio.h | 4 ++-- 6 files changed, 13 insertions(+), 14 deletions(-)