From e70344c05995a190a56bbd1a23dc2218bcc8c924 Mon Sep 17 00:00:00 2001 From: Damien Le Moal Date: Wed, 11 Aug 2021 12:37:02 +0900 Subject: [PATCH] block: fix default IO priority handling 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 Link: https://lore.kernel.org/r/20210811033702.368488-7-damien.lemoal@wdc.com [axboe: drop unnecessary lightnvm change] Signed-off-by: Jens Axboe --- block/bfq-iosched.c | 2 +- block/ioprio.c | 6 +++--- include/linux/ioprio.h | 7 ++++++- include/uapi/linux/ioprio.h | 5 +++-- 4 files changed, 13 insertions(+), 7 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 @@ out: 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/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 +/* + * 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 */