From e8a5a1ad7154dc34e3a5234267e19faa86d5ff33 Mon Sep 17 00:00:00 2001 From: "Jason A. Harmening" Date: Wed, 30 Dec 2020 15:29:44 -0800 Subject: rctl(4): support throttling resource usage to 0 For rate-based resources that support throttling (e.g. readiops/writeips), this fixes a divide-by-zero panic when rctl(8) passes 0 as the throttle value. For these resources, treat zero-throttle requests as requests to suspend forward progress as long as possible using the duration specified in kern.racct.rctl.throttle_max. PR: 251803 Reported by: chris@cretaforce.gr Reviewed by: kib MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D27858 --- sys/kern/kern_rctl.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/sys/kern/kern_rctl.c b/sys/kern/kern_rctl.c index 9a0e0651750f..90e2f7832691 100644 --- a/sys/kern/kern_rctl.c +++ b/sys/kern/kern_rctl.c @@ -600,6 +600,11 @@ rctl_enforce(struct proc *p, int resource, uint64_t amount) if (p->p_state != PRS_NORMAL) continue; + if (rule->rr_amount == 0) { + racct_proc_throttle(p, rctl_throttle_max); + continue; + } + /* * Make the process sleep for a fraction of second * proportional to the ratio of process' resource -- cgit v1.2.3