| Message ID | 1cbcee1a6a39abb41768a6b1c69ec8751ed0215a.1743656654.git.ritesh.list@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [RFC] traceevent/block: Add REQ_ATOMIC flag to block trace events | expand |
On 03/04/2025 06:28, Ritesh Harjani (IBM) wrote: > Filesystems like XFS can implement atomic write I/O using either REQ_ATOMIC > flag set in the bio or via CoW operation. It will be useful if we have a > flag in trace events to distinguish between the two. I suppose that this could be useful. So far I test with block driver traces, i.e. NVMe or SCSI internal traces, just to ensure that we see the requests sent as expected This patch adds > char 'a' to rwbs field of the trace events if REQ_ATOMIC flag is set in > the bio. All others use uppercase characters, so I suggest that you continue to use that. Since 'A' is already used, how about 'U' for untorn? Or 'T' for aTOMic :) > > <W/ REQ_ATOMIC> > ================= > xfs_io-1107 [002] ..... 406.206441: block_rq_issue: 8,48 WSa 16384 () 768 + 32 none,0,0 [xfs_io] > <idle>-0 [002] ..s1. 406.209918: block_rq_complete: 8,48 WSa () 768 + 32 none,0,0 [0] > > <W/O REQ_ATOMIC> > =============== > xfs_io-1108 [002] ..... 411.212317: block_rq_issue: 8,48 WS 16384 () 1024 + 32 none,0,0 [xfs_io] > <idle>-0 [002] ..s1. 411.215842: block_rq_complete: 8,48 WS () 1024 + 32 none,0,0 [0] > > Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> > --- > include/trace/events/block.h | 2 +- > kernel/trace/blktrace.c | 2 ++ > 2 files changed, 3 insertions(+), 1 deletion(-) > > diff --git a/include/trace/events/block.h b/include/trace/events/block.h > index bd0ea07338eb..de538b110ea1 100644 > --- a/include/trace/events/block.h > +++ b/include/trace/events/block.h > @@ -11,7 +11,7 @@ > #include <linux/tracepoint.h> > #include <uapi/linux/ioprio.h> > > -#define RWBS_LEN 8 > +#define RWBS_LEN 9 > > #define IOPRIO_CLASS_STRINGS \ > { IOPRIO_CLASS_NONE, "none" }, \ > diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c > index 3679a6d18934..6badf296ab2b 100644 > --- a/kernel/trace/blktrace.c > +++ b/kernel/trace/blktrace.c > @@ -1896,6 +1896,8 @@ void blk_fill_rwbs(char *rwbs, blk_opf_t opf) > rwbs[i++] = 'S'; > if (opf & REQ_META) > rwbs[i++] = 'M'; > + if (opf & REQ_ATOMIC) > + rwbs[i++] = 'a'; > > rwbs[i] = '\0'; > } > -- > 2.48.1 >
John Garry <john.g.garry@oracle.com> writes: > On 03/04/2025 06:28, Ritesh Harjani (IBM) wrote: >> Filesystems like XFS can implement atomic write I/O using either REQ_ATOMIC >> flag set in the bio or via CoW operation. It will be useful if we have a >> flag in trace events to distinguish between the two. > > I suppose that this could be useful. So far I test with block driver > traces, i.e. NVMe or SCSI internal traces, just to ensure that we see > the requests sent as expected > Right. > This patch adds >> char 'a' to rwbs field of the trace events if REQ_ATOMIC flag is set in >> the bio. > > All others use uppercase characters, so I suggest that you continue to > use that. It will be good to know on whether only uppercase characters are allowed or we are good with smallcase characters too? > Since 'A' is already used, how about 'U' for untorn? Or 'T' > for aTOMic :) > If 'a' is not allowed, then we can change it to 'T' maybe. -ritesh >> >> <W/ REQ_ATOMIC> >> ================= >> xfs_io-1107 [002] ..... 406.206441: block_rq_issue: 8,48 WSa 16384 () 768 + 32 none,0,0 [xfs_io] >> <idle>-0 [002] ..s1. 406.209918: block_rq_complete: 8,48 WSa () 768 + 32 none,0,0 [0] >> >> <W/O REQ_ATOMIC> >> =============== >> xfs_io-1108 [002] ..... 411.212317: block_rq_issue: 8,48 WS 16384 () 1024 + 32 none,0,0 [xfs_io] >> <idle>-0 [002] ..s1. 411.215842: block_rq_complete: 8,48 WS () 1024 + 32 none,0,0 [0] >> >> Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> >> --- >> include/trace/events/block.h | 2 +- >> kernel/trace/blktrace.c | 2 ++ >> 2 files changed, 3 insertions(+), 1 deletion(-) >> >> diff --git a/include/trace/events/block.h b/include/trace/events/block.h >> index bd0ea07338eb..de538b110ea1 100644 >> --- a/include/trace/events/block.h >> +++ b/include/trace/events/block.h >> @@ -11,7 +11,7 @@ >> #include <linux/tracepoint.h> >> #include <uapi/linux/ioprio.h> >> >> -#define RWBS_LEN 8 >> +#define RWBS_LEN 9 >> >> #define IOPRIO_CLASS_STRINGS \ >> { IOPRIO_CLASS_NONE, "none" }, \ >> diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c >> index 3679a6d18934..6badf296ab2b 100644 >> --- a/kernel/trace/blktrace.c >> +++ b/kernel/trace/blktrace.c >> @@ -1896,6 +1896,8 @@ void blk_fill_rwbs(char *rwbs, blk_opf_t opf) >> rwbs[i++] = 'S'; >> if (opf & REQ_META) >> rwbs[i++] = 'M'; >> + if (opf & REQ_ATOMIC) >> + rwbs[i++] = 'a'; >> >> rwbs[i] = '\0'; >> } >> -- >> 2.48.1 >>
diff --git a/include/trace/events/block.h b/include/trace/events/block.h index bd0ea07338eb..de538b110ea1 100644 --- a/include/trace/events/block.h +++ b/include/trace/events/block.h @@ -11,7 +11,7 @@ #include <linux/tracepoint.h> #include <uapi/linux/ioprio.h> -#define RWBS_LEN 8 +#define RWBS_LEN 9 #define IOPRIO_CLASS_STRINGS \ { IOPRIO_CLASS_NONE, "none" }, \ diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index 3679a6d18934..6badf296ab2b 100644 --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -1896,6 +1896,8 @@ void blk_fill_rwbs(char *rwbs, blk_opf_t opf) rwbs[i++] = 'S'; if (opf & REQ_META) rwbs[i++] = 'M'; + if (opf & REQ_ATOMIC) + rwbs[i++] = 'a'; rwbs[i] = '\0'; }
Filesystems like XFS can implement atomic write I/O using either REQ_ATOMIC flag set in the bio or via CoW operation. It will be useful if we have a flag in trace events to distinguish between the two. This patch adds char 'a' to rwbs field of the trace events if REQ_ATOMIC flag is set in the bio. <W/ REQ_ATOMIC> ================= xfs_io-1107 [002] ..... 406.206441: block_rq_issue: 8,48 WSa 16384 () 768 + 32 none,0,0 [xfs_io] <idle>-0 [002] ..s1. 406.209918: block_rq_complete: 8,48 WSa () 768 + 32 none,0,0 [0] <W/O REQ_ATOMIC> =============== xfs_io-1108 [002] ..... 411.212317: block_rq_issue: 8,48 WS 16384 () 1024 + 32 none,0,0 [xfs_io] <idle>-0 [002] ..s1. 411.215842: block_rq_complete: 8,48 WS () 1024 + 32 none,0,0 [0] Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> --- include/trace/events/block.h | 2 +- kernel/trace/blktrace.c | 2 ++ 2 files changed, 3 insertions(+), 1 deletion(-) -- 2.48.1