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| author | Damien Le Moal <damien.lemoal@wdc.com> | 2021-08-11 06:36:58 +0300 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2021-08-18 16:21:11 +0300 |
| commit | 25bca50e523cbe96c0207fbb92f22ff2bc28e9aa (patch) | |
| tree | b089daeeef7880d4b6ae71b9797ec729c1eebab7 | |
| parent | a680dd72ec336b81511e3bff48efac6dbfa563e7 (diff) | |
| download | linux-25bca50e523cbe96c0207fbb92f22ff2bc28e9aa.tar.xz | |
block: improve ioprio class description comment
In include/usapi/linux/ioprio.h, change the ioprio class enum comment
to remove the outdated reference to CFQ and mention BFQ and mq-deadline
instead. Also document the high priority NCQ command use for RT class
IOs directed at ATA drives that support NCQ priority.
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Link: https://lore.kernel.org/r/20210811033702.368488-3-damien.lemoal@wdc.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | include/uapi/linux/ioprio.h | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/include/uapi/linux/ioprio.h b/include/uapi/linux/ioprio.h index 77b17e08b0da..6b735854aebd 100644 --- a/include/uapi/linux/ioprio.h +++ b/include/uapi/linux/ioprio.h @@ -13,10 +13,12 @@ #define IOPRIO_PRIO_VALUE(class, data) (((class) << IOPRIO_CLASS_SHIFT) | data) /* - * These are the io priority groups as implemented by CFQ. RT is the realtime - * class, it always gets premium service. BE is the best-effort scheduling - * class, the default for any process. IDLE is the idle scheduling class, it - * is only served when no one else is using the disk. + * These are the io priority groups as implemented by the BFQ and mq-deadline + * schedulers. RT is the realtime class, it always gets premium service. For + * ATA disks supporting NCQ IO priority, RT class IOs will be processed using + * high priority NCQ commands. BE is the best-effort scheduling class, the + * default for any process. IDLE is the idle scheduling class, it is only + * served when no one else is using the disk. */ enum { IOPRIO_CLASS_NONE, |