On Tue, Jan 9, 2018 at 12:41 AM, Michael Jung <mi...@mikej.com> wrote:
> On 2018-01-08 13:39, John Baldwin wrote: > >> On Tuesday, November 28, 2017 02:46:03 PM Michael Jung wrote: >> >>> Hi! >>> >>> I've recently up'd my processor count on our poudriere box and have >>> started noticing the error >>> "witness_lock_list_get: witness exhausted" on the console. The kernel >>> *DOES NOT* crash but I >>> thought the report may be useful to someone. >>> >>> $ uname -a >>> FreeBSD poudriere 12.0-CURRENT FreeBSD 12.0-CURRENT #1 r325999: Sun Nov >>> 19 18:41:20 EST 2017 >>> mikej@poudriere:/usr/obj/usr/src/amd64.amd64/sys/GENERIC amd64 >>> >>> The machine is pretty busy running four poudriere build instances. >>> >>> last pid: 76584; load averages: 115.07, 115.96, 98.30 >>> >>> up 6+07:32:59 14:44:03 >>> 763 processes: 117 running, 581 sleeping, 2 zombie, 63 lock >>> CPU: 59.0% user, 0.0% nice, 40.7% system, 0.1% interrupt, 0.1% idle >>> Mem: 12G Active, 2003M Inact, 44G Wired, 29G Free >>> ARC: 28G Total, 11G MFU, 16G MRU, 122M Anon, 359M Header, 1184M Other >>> 25G Compressed, 32G Uncompressed, 1.24:1 Ratio >>> >>> Let me know what additional information I might supply. >>> >> >> This just means that WITNESS stopped working because it ran out of >> pre-allocated objects. In particular the objects used to track how >> many locks are held by how many threads: >> >> /* >> * XXX: This is somewhat bogus, as we assume here that at most 2048 >> threads >> * will hold LOCK_NCHILDREN locks. We handle failure ok, and we should >> * probably be safe for the most part, but it's still a SWAG. >> */ >> #define LOCK_NCHILDREN 5 >> #define LOCK_CHILDCOUNT 2048 >> >> Probably the '2048' (max number of concurrent threads) needs to scale with >> MAXCPU. 2048 threads is probably a bit low on big x86 boxes. >> > > > Thank you for you explanation. We are expanding our ESXi cluster and even > though with standard edition I can only assign 64 vCPU's to a guest and as > much > RAM as I want, I do like to help with edge cases if I can make them occur > pushing > boundaries as I can towards additianional improvements in FreeBSD. > Can you apply this and re-run the test? https://people.freebsd.org/~mjg/witness.diff It bumps the counters to be "high enough" but also starts tracking usage. If you get the message again, bump the values even higher. Once you get a complete poudriere run which did not result in the problem, do: $ sysctl debug.witness.list_used debug.witness.list_max_used to dump the actual usage. -- Mateusz Guzik <mjguzik gmail.com> _______________________________________________ email@example.com mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"