From d21c19d4127bb58ab8de83dc944c3ebfc3b43af5 Mon Sep 17 00:00:00 2001 From: Warner Losh Date: Thu, 2 May 2024 15:58:55 -0600 Subject: [PATCH] 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 b83ab969942..471e6c355d6 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