Messages in this thread | | | Subject | Re: [BUG] Deadlock due due to interactions of block, RCU, and cpu offline | From | Jeffrey Hugo <> | Date | Thu, 29 Jun 2017 10:29:12 -0600 |
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On 6/27/2017 6:11 PM, Paul E. McKenney wrote: > On Tue, Jun 27, 2017 at 04:32:09PM -0600, Jeffrey Hugo wrote: >> On 6/22/2017 9:34 PM, Paul E. McKenney wrote: >>> On Wed, Jun 21, 2017 at 09:18:53AM -0700, Paul E. McKenney wrote: >>>> No worries, and I am very much looking forward to seeing the results of >>>> your testing. >>> >>> And please see below for an updated patch based on LKML review and >>> more intensive testing. >>> >> >> I spent some time on this today. It didn't go as I expected. I >> validated the issue is reproducible as before on 4.11 and 4.12 rcs 1 >> through 4. However, the version of stress-ng that I was using ran >> into constant errors starting with rc5, making it nearly impossible >> to make progress toward reproduction. Upgrading stress-ng to tip >> fixes the issue, however, I've still been unable to repro the issue. >> >> Its my unfounded suspicion that something went in between rc4 and >> rc5 which changed the timing, and didn't actually fix the issue. I >> will run the test overnight for 5 hours to try to repro. >> >> The patch you sent appears to be based on linux-next, and appears to >> have a number of dependencies which prevent it from cleanly applying >> on anything current that I'm able to repro on at this time. Do you >> want to provide a rebased version of the patch which applies to say >> 4.11? I could easily test that and report back. > > Here is a very lightly tested backport to v4.11. >
Works for me. Always reproduced the lockup within 2 minutes on stock 4.11. With the change applied, I was able to test for 2 hours in the same conditions, and 4 hours with the full system and not encounter an issue.
Feel free to add: Tested-by: Jeffrey Hugo <jhugo@codeaurora.org>
I'm going to go back to 4.12-rc5 and see if I can get either repro the issue, or identify what changed. Hopefully I can get to linux-next and double check the original version of the change as well.
-- Jeffrey Hugo Qualcomm Datacenter Technologies as an affiliate of Qualcomm Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.
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