Messages in this thread | | | Date | Fri, 17 Apr 2015 09:48:08 -0600 | From | Jens Axboe <> | Subject | Re: [GIT PULL] Followup single fix for block IO core pull |
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On 04/17/2015 09:45 AM, Jens Axboe wrote: > On 04/17/2015 09:41 AM, Dave Jones wrote: >> On Fri, Apr 17, 2015 at 09:12:01AM -0600, Jens Axboe wrote: >> > Hi Linus, >> > >> > A commit in the previous pull request introduce a regression. So far >> > only observed on qemu-sparc64, but it's a general bug. Please pull >> this >> > single fix to rectify that, thanks. >> >> I hit the same bug on two x86 boxes, bare-metal. >> Reverting the commit Guenter pointed out made them boot again, >> so definitely not sparc/qemu specific in any way. >> >> I suspect the only reason more people didn't see it is that not >> everyone is running with the mq-by-default config option yet ? > > It is puzzling. I ran it on several boxes, both multi queue and not, and > both single mq queues and multiple. But the code is clearly wrong. So > yeah, it's not sparc64 specific in any way. My initial thought was that > this was another issue related to sparse CPU ids, but that's not the > case. It's a plain bug, unfortunately.
It's the pre morning coffee issue, looks like. All my test boxes end up having >= map->bits_per_word CPUs, so the test cases never ran into the round down issue.
-- Jens Axboe
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