From: Konstantin Khlebnikov Date: Thu, 11 Oct 2018 07:07:06 +0000 (+0300) Subject: block: describe difference between flags IO_STAT and STATS X-Git-Tag: v4.20-rc1~191^2~46 X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=4822e902f9bdffaea2817471365e000966f0d1a1;p=uclinux-h8%2Flinux.git block: describe difference between flags IO_STAT and STATS This adds reasonable comments, but they definitely needs better names. Signed-off-by: Konstantin Khlebnikov Signed-off-by: Jens Axboe --- diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index dee46c20701b..61207560e826 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -108,7 +108,7 @@ typedef __u32 __bitwise req_flags_t; #define RQF_QUIET ((__force req_flags_t)(1 << 11)) /* elevator private data attached */ #define RQF_ELVPRIV ((__force req_flags_t)(1 << 12)) -/* account I/O stat */ +/* account into disk and partition IO statistics */ #define RQF_IO_STAT ((__force req_flags_t)(1 << 13)) /* request came from our alloc pool */ #define RQF_ALLOCED ((__force req_flags_t)(1 << 14)) @@ -116,7 +116,7 @@ typedef __u32 __bitwise req_flags_t; #define RQF_PM ((__force req_flags_t)(1 << 15)) /* on IO scheduler merge hash */ #define RQF_HASHED ((__force req_flags_t)(1 << 16)) -/* IO stats tracking on */ +/* track IO completion time */ #define RQF_STATS ((__force req_flags_t)(1 << 17)) /* Look at ->special_vec for the actual data payload instead of the bio chain. */ @@ -685,7 +685,7 @@ struct request_queue { #define QUEUE_FLAG_FAIL_IO 7 /* fake timeout */ #define QUEUE_FLAG_NONROT 9 /* non-rotational device (SSD) */ #define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */ -#define QUEUE_FLAG_IO_STAT 10 /* do IO stats */ +#define QUEUE_FLAG_IO_STAT 10 /* do disk/partitions IO accounting */ #define QUEUE_FLAG_DISCARD 11 /* supports DISCARD */ #define QUEUE_FLAG_NOXMERGES 12 /* No extended merges */ #define QUEUE_FLAG_ADD_RANDOM 13 /* Contributes to random pool */ @@ -699,7 +699,7 @@ struct request_queue { #define QUEUE_FLAG_FUA 21 /* device supports FUA writes */ #define QUEUE_FLAG_FLUSH_NQ 22 /* flush not queueuable */ #define QUEUE_FLAG_DAX 23 /* device supports DAX */ -#define QUEUE_FLAG_STATS 24 /* track rq completion times */ +#define QUEUE_FLAG_STATS 24 /* track IO start and completion times */ #define QUEUE_FLAG_POLL_STATS 25 /* collecting stats for hybrid polling */ #define QUEUE_FLAG_REGISTERED 26 /* queue has been registered to a disk */ #define QUEUE_FLAG_SCSI_PASSTHROUGH 27 /* queue supports SCSI commands */