git: d21c19d4127b - main - cam/iosched: Document latency buckets correctly.

The branch main has been updated by imp:

URL: https://cgit.FreeBSD.org/src/commit/?id=d21c19d4127bb58ab8de83dc944c3ebfc3b43af5

commit d21c19d4127bb58ab8de83dc944c3ebfc3b43af5
Author:     Warner Losh <imp@FreeBSD.org>
AuthorDate: 2024-05-02 21:58:55 +0000
Commit:     Warner Losh <imp@FreeBSD.org>
CommitDate: 2024-05-02 22:02:04 +0000

    cam/iosched: Document latency buckets correctly.
    
    Document how latency buckets are actually computed: They are a doubling
    from 20us to 10.485s by default, but based at
    kern.cam.iosched.bucket_base_us and increase with a ratio of
    kern.cam.iosched.bucket_ration / 100 from one to the next.
    
    Sponsored by:           Netflix
---
 sys/cam/cam_iosched.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/sys/cam/cam_iosched.c b/sys/cam/cam_iosched.c
index b83ab9699425..471e6c355d69 100644
--- a/sys/cam/cam_iosched.c
+++ b/sys/cam/cam_iosched.c
@@ -1070,7 +1070,12 @@ cam_iosched_iop_stats_sysctl_init(struct cam_iosched_softc *isc, struct iop_stat
 	    CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE,
 	    &ios->latencies, 0,
 	    cam_iosched_sysctl_latencies, "A",
-	    "Array of power of 2 latency from 1ms to 1.024s");
+	    "Array of latencies, a geometric progresson from\n"
+	    "kern.cam.iosched.bucket_base_us with a ratio of\n"
+	    "kern.cam.iosched.bucket_ration / 100 from one to\n"
+	    "the next. By default 20 steps from 20us to 10.485s\n"
+	    "by doubling.");
+
 }
 
 static void