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| author | Damien Le Moal <damien.lemoal@wdc.com> | 2021-08-11 12:37:02 +0900 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2021-08-18 07:23:15 -0600 |
| commit | e70344c05995a190a56bbd1a23dc2218bcc8c924 (patch) | |
| tree | 36a1c67d06e9d74264bc6289e09127dff37c4fa7 /block/ioprio.c | |
| parent | 202bc942c5cd4340d37b06c4e0b8b03f9925d818 (diff) | |
| download | lwn-e70344c05995a190a56bbd1a23dc2218bcc8c924.tar.gz lwn-e70344c05995a190a56bbd1a23dc2218bcc8c924.zip | |
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 <damien.lemoal@wdc.com>
Link: https://lore.kernel.org/r/20210811033702.368488-7-damien.lemoal@wdc.com
[axboe: drop unnecessary lightnvm change]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/ioprio.c')
| -rw-r--r-- | block/ioprio.c | 6 |
1 files changed, 3 insertions, 3 deletions
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); } |