> Il giorno 10 feb 2017, alle ore 20:49, Paolo Valente > <paolo.vale...@linaro.org> ha scritto: > >> >> Il giorno 10 feb 2017, alle ore 19:13, Bart Van Assche >> <bart.vanass...@sandisk.com> ha scritto: >> >> On 02/10/2017 08:49 AM, Paolo Valente wrote: >>>> $ grep '^C.*_MQ_' .config >>>> CONFIG_BLK_MQ_PCI=y >>>> CONFIG_MQ_IOSCHED_BFQ=y >>>> CONFIG_MQ_IOSCHED_DEADLINE=y >>>> CONFIG_MQ_IOSCHED_NONE=y >>>> CONFIG_DEFAULT_MQ_BFQ_MQ=y >>>> CONFIG_DEFAULT_MQ_IOSCHED="bfq-mq" >>>> CONFIG_SCSI_MQ_DEFAULT=y >>>> CONFIG_DM_MQ_DEFAULT=y >>>> >>> >>> Could you reconfigure with none or mq-deadline as default, check >>> whether the system boots, and, it it does, switch manually to bfq-mq, >>> check what happens, and, in the likely case of a failure, try to get >>> the oops? >> >> Hello Paolo, >> >> I just finished performing that test with the following kernel config: >> $ grep '^C.*_MQ_' .config >> CONFIG_BLK_MQ_PCI=y >> CONFIG_MQ_IOSCHED_BFQ=y >> CONFIG_MQ_IOSCHED_DEADLINE=y >> CONFIG_MQ_IOSCHED_NONE=y >> CONFIG_DEFAULT_MQ_DEADLINE=y >> CONFIG_DEFAULT_MQ_IOSCHED="mq-deadline" >> CONFIG_SCSI_MQ_DEFAULT=y >> CONFIG_DM_MQ_DEFAULT=y >> >> After the system came up I logged in, switched to the bfq-mq scheduler >> and ran several I/O tests against the boot disk. > > Without any failure, right? > > Unfortunately, as you can imagine, no boot failure occurred on > any of my test systems so far :( > > This version of bfq-mq can be configured to print all its activity in > the kernel log, by just defining a macro. This will of course slow > down the system so much to make it probably unusable, if bfq-mq is > active from boot. Yet, the failure may still occur so early to make > this approach useful to discover where bfq-mq gets stuck. As of now I > have no better ideas. Any suggestion is welcome. >
Hi Bart, I have found a machine crashing at boot, yet not only when bfq-mq is chosen, but also when mq-deadline is chosen as the default scheduler. I have found and just reported the cause of the failure, together with a fix. Probably this is not the cause of your failure, but what do you think about trying this fix? BTW, I have rebased the branch [1] against the new commits in Jens for-4.11/next. Otherwise, if you have no news or suggestions, would you be willing to try my micro-logging proposal? Thanks, Paolo [1] https://github.com/Algodev-github/bfq-mq > Thanks, > Paolo > >> Sorry but nothing >> interesting appeared in the kernel log. >> >> Bart. >> Western Digital Corporation (and its subsidiaries) E-mail Confidentiality >> Notice & Disclaimer: >> >> This e-mail and any files transmitted with it may contain confidential or >> legally privileged information of WDC and/or its affiliates, and are >> intended solely for the use of the individual or entity to which they are >> addressed. If you are not the intended recipient, any disclosure, copying, >> distribution or any action taken or omitted to be taken in reliance on it, >> is prohibited. If you have received this e-mail in error, please notify the >> sender immediately and delete the e-mail in its entirety from your system.
