[PATCH v4 6/6] block: fix default IO priority handling
From: Damien Le Moal <hidden>
Date: 2021-08-11 03:37:30
Also in:
linux-f2fs-devel
Subsystem:
bfq i/o scheduler, block layer, nvm express driver, the rest · Maintainers:
Yu Kuai, Jens Axboe, Keith Busch, Christoph Hellwig, Sagi Grimberg, Linus Torvalds
The default IO priority is the best effort (BE) class with the normal priority level IOPRIO_NORM (4). However, get_task_ioprio() returns IOPRIO_CLASS_NONE/IOPRIO_NORM as the default priority and get_current_ioprio() returns IOPRIO_CLASS_NONE/0. Let's be consistent with the defined default and have both of these functions return the default priority IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, IOPRIO_NORM) when the user did not define another default IO priority for the task. In include/uapi/linux/ioprio.h, introduce the IOPRIO_BE_NORM macro as an alias to IOPRIO_NORM to clarify that this default level applies to the BE priotity class. In include/linux/ioprio.h, define the macro IOPRIO_DEFAULT as IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, IOPRIO_BE_NORM) and use this new macro when setting a priority to the default. Signed-off-by: Damien Le Moal <redacted> --- block/bfq-iosched.c | 2 +- block/ioprio.c | 6 +++--- drivers/nvme/host/lightnvm.c | 2 +- include/linux/ioprio.h | 7 ++++++- include/uapi/linux/ioprio.h | 5 +++-- 5 files changed, 14 insertions(+), 8 deletions(-)
diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index 4b434369e411..e92bc0348433 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c@@ -5411,7 +5411,7 @@ static struct bfq_queue **bfq_async_queue_prio(struct bfq_data *bfqd, case IOPRIO_CLASS_RT: return &bfqg->async_bfqq[0][ioprio]; case IOPRIO_CLASS_NONE: - ioprio = IOPRIO_NORM; + ioprio = IOPRIO_BE_NORM; fallthrough; case IOPRIO_CLASS_BE: return &bfqg->async_bfqq[1][ioprio];
diff --git a/block/ioprio.c b/block/ioprio.c
index ca6b136c5586..0e4ff245f2bf 100644
--- a/block/ioprio.c
+++ b/block/ioprio.c@@ -170,7 +170,7 @@ static int get_task_ioprio(struct task_struct *p) ret = security_task_getioprio(p); if (ret) goto out; - ret = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_NONE, IOPRIO_NORM); + ret = IOPRIO_DEFAULT; task_lock(p); if (p->io_context) ret = p->io_context->ioprio;
@@ -182,9 +182,9 @@ static int get_task_ioprio(struct task_struct *p) int ioprio_best(unsigned short aprio, unsigned short bprio) { if (!ioprio_valid(aprio)) - aprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, IOPRIO_NORM); + aprio = IOPRIO_DEFAULT; if (!ioprio_valid(bprio)) - bprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, IOPRIO_NORM); + bprio = IOPRIO_DEFAULT; return min(aprio, bprio); }
diff --git a/drivers/nvme/host/lightnvm.c b/drivers/nvme/host/lightnvm.c
index e9d9ad47f70f..0fbbff0b3edb 100644
--- a/drivers/nvme/host/lightnvm.c
+++ b/drivers/nvme/host/lightnvm.c@@ -662,7 +662,7 @@ static struct request *nvme_nvm_alloc_request(struct request_queue *q, if (rqd->bio) blk_rq_append_bio(rq, rqd->bio); else - rq->ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, IOPRIO_NORM); + rq->ioprio = IOPRIO_DEFAULT; return rq; }
diff --git a/include/linux/ioprio.h b/include/linux/ioprio.h
index 2ee3373684b1..3f53bc27a19b 100644
--- a/include/linux/ioprio.h
+++ b/include/linux/ioprio.h@@ -8,6 +8,11 @@ #include <uapi/linux/ioprio.h> +/* + * Default IO priority. + */ +#define IOPRIO_DEFAULT IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, IOPRIO_BE_NORM) + /* * Check that a priority value has a valid class. */
@@ -51,7 +56,7 @@ static inline int get_current_ioprio(void) if (ioc) return ioc->ioprio; - return IOPRIO_PRIO_VALUE(IOPRIO_CLASS_NONE, 0); + return IOPRIO_DEFAULT; } /*
diff --git a/include/uapi/linux/ioprio.h b/include/uapi/linux/ioprio.h
index aac39338d02c..f70f2596a6bf 100644
--- a/include/uapi/linux/ioprio.h
+++ b/include/uapi/linux/ioprio.h@@ -44,8 +44,9 @@ enum { }; /* - * Fallback BE priority + * Fallback BE priority level. */ -#define IOPRIO_NORM (4) +#define IOPRIO_NORM 4 +#define IOPRIO_BE_NORM IOPRIO_NORM #endif /* _UAPI_LINUX_IOPRIO_H */
--
2.31.1