On 2017年10月20日 17:25, Po-Hsu Lin wrote: > Thanks for the info. > > I have checked the comment inside the test case, which state that: > # And unfortunately, btrfs send is one of these operations, and will cause > # softlock or OOM on systems with small memory(<4G). > > To my experience, this will stuck on a system with 32G memory too.
Sorry for the confusion, I mean softlock if you have enough memory. And if you don't have enough memory, you will get an OOM. > > And in the end of the script, it says: > # send out the subvolume, and it will either: > # 1) OOM since memory is allocated inside a O(n^3) loop > # 2) Softlock since time consuming backref walk is called without scheduling. > > I can see the soft lockup behaviour (I guess this is the second result > listed above?) from dmesg as described in > https://bugs.launchpad.net/bugs/1718925 > > So I'm curious that does anyone know how long it might take if this test > works? Just skip it, or make it dangerous. (Which I should do it in the very beginning) Thanks, Qu > Tried 8 hours as a timeout limit but no luck. Or maybe this test is > totally broken? > > Thanks! > > On Tue, Oct 17, 2017 at 9:03 PM, Jeff Mahoney <je...@suse.com> wrote: >> On 10/17/17 8:46 AM, Qu Wenruo wrote: >>> >>> >>> On 2017年10月17日 19:11, Po-Hsu Lin wrote: >>>> Hello Chris, >>>> >>>> I can reproduce this on my side too, with Ubuntu 16.04 + 4.4.0-97 kernel. >>> >>> Btrfs/130 is a known bug. >>> >>> I submitted it to raise the concern about such situation and purposed >>> one possible solution (just disable deduped file detection). >>> >>> But the solution doesn't get accepted. >> >> It also works very well as a performance test for qgroup runtime >> improvements. :) >> >> -Jeff >> >>> Thanks, >>> Qu >>>> >>>> PREEMPT config: >>>> $ cat config-4.4.0-97-generic | grep PREEMPT >>>> CONFIG_PREEMPT_NOTIFIERS=y >>>> # CONFIG_PREEMPT_NONE is not set >>>> CONFIG_PREEMPT_VOLUNTARY=y >>>> # CONFIG_PREEMPT is not set >>>> >>>> Bug reports on launchpad: >>>> https://bugs.launchpad.net/bugs/1718925 >>>> https://bugs.launchpad.net/bugs/1717443 >>>> -- >>>> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in >>>> the body of a message to majord...@vger.kernel.org >>>> More majordomo info at http://vger.kernel.org/majordomo-info.html >>>> >>> >> >> >> -- >> Jeff Mahoney >> SUSE Labs >> > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
