On 11/16/11 16:14, Bjoern A. Zeeb wrote: > On Wed, 16 Nov 2011, Alexander Motin wrote: > >> Hi. >> >> On 11/16/11 08:43, Bjoern A. Zeeb wrote: >>> we have seen this or a very similar panic for about 1 year now once in >>> a while and I think I reported it before; this is FreeBSD as guest on >>> vmware. Seems it was a double panic this time. Could someone please >>> see what's going on there? It was on 8.x-STABLE in the past and this >>> is 8.2-RELEASE-p4. >> >> The part of code reporting "completing request directly" is IMHO broken >> by design. It returns request completion before request will actually be >> completed by lower levels without any knowledge of what's going on >> there. There is kind of protection against double request completion, >> but it looks like not always working. May be because that part of code >> is not locked and nothing prevents that semaphore timeout and normal >> request timeout/completion to happen simultaneously. It is surprising to >> see even two traps same time, not sure what synchronized them so >> precisely. >> >> Simple removing that semaphore timeout is not an option, because it will >> cause deadlock when this wait happen within taskqueue thread that is >> used to handle requests completion and abort that wait. Avoid waiting >> inside taskqueue is also impossible without major rewrite. That's why >> ATA_CAM drops that code completely. > > So the bottom line of what you are saying is: > 1) it's hard to fix right in 8 > 2) it's not an issue in 9 anymore at all?
Right. -- Alexander Motin _______________________________________________ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
