system/freebsd-src
system/freebsd-src
1
0
Fork 0
mirror of https://github.com/freebsd/freebsd-src synced 2024-10-01 14:14:56 +00:00
Code Issues Packages Projects Releases Wiki Activity

cam/iosched: Document latency buckets correctly.

Browse source 
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
This commit is contained in:
Warner Losh 2024-05-02 15:58:55 -06:00
parent b25ceb97ed
commit d21c19d412
1 changed files with 6 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

7
sys/cam/cam_iosched.c
View file

@ -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