From: Damien Le Moal Date: Wed, 11 Aug 2021 03:36:58 +0000 (+0900) Subject: block: improve ioprio class description comment X-Git-Tag: v5.15-rc1~189^2~39 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=25bca50e523cbe96c0207fbb92f22ff2bc28e9aa;p=thirdparty%2Flinux.git 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ioprio class description comment In include/usapi/linux/ioprio.h, change the ioprio class enum comment to remove the outdated reference to CFQ and mention BFQ and mq-deadline instead.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 Link: https://lore.kernel.org/r/20210811033702.368488-3-damien.lemoal@wdc.com Signed-off-by: Jens Axboe --- diff --git a/include/uapi/linux/ioprio.h b/include/uapi/linux/ioprio.h index 77b17e08b0da1..6b735854aebd2 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,