Re: ZFS + FreeBSD XEN dom0 panic
- Reply: Roger Pau Monné : "Re: ZFS + FreeBSD XEN dom0 panic"
- In reply to: Roger Pau Monné : "Re: ZFS + FreeBSD XEN dom0 panic"
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Date: Thu, 14 Apr 2022 06:47:19 UTC
On 2022.04.12. 18:37, Roger Pau Monné wrote: > > I have a patch to disable the bounce buffering done in blkback > (attached). Regarding this patch, it wouldn't apply on RELEASE 13.0 code, because i guess there are other changes, when updating code manually i got compile error, variable xen_cpuid_base not defined, and include paths do not have <contrib> at the start. So i applied it manually to main branch, commit: 2f0baec1ecb2e79cfb97a19e1bbfb27741365847, since there at least variable xen_cpuid_base existed. > While I think it's not directly related to the panic you are hitting, > it's long time since we should have disabled that. It should reduce > the memory consumption by blkback greatly, so might have the side > effect of helping with your issue related to pmap_growkernel. I think i do not understand this clearly. Was it an obsolete feature that had to be removed? > On my test box a single instance of blkback reduced memory usage from > ~100M to ~300K. On my lab system this seems to work quiet niceley as well. System is under load now for 17:36 hours, no panic, collecting vmstat. And what else is different, that VM start/stop script has not printed any error about adding block devices. So this seems promissing.