Am 23.10.2017 um 16:39 schrieb Coly Li: > On 2017/10/23 下午10:26, Stefan Priebe - Profihost AG wrote: >> Hi, >> Am 23.10.2017 um 16:00 schrieb Coly Li: >>> On 2017/10/23 下午9:16, Stefan Priebe - Profihost AG wrote: >>>> Hi, >>>> >>>> Am 23.10.2017 um 15:05 schrieb Coly Li: >>>>> On 2017/10/23 下午8:59, Stefan Priebe - Profihost AG wrote: >>>>>> Hi Coly, >>>>>> >>>>>> >>>>>> Am 23.10.2017 um 14:56 schrieb Coly Li: >>>>>>> On 2017/10/23 下午7:42, Stefan Priebe - Profihost AG wrote: >>>>>>>> Hello, >>>>>>>> >>>>>>>> i picked all bcache patches from for-next to my 4.4 kernel to test the >>>>>>>> new controller. >>>>>>>> >>>>>>>> After doing so i see random kernel panics with the following trace: >>>>>>> >>>>>>> Hi Stefan, >>>>>>> >>>>>>> Thanks for the report. This is the 3rd report I see recently for NULL >>>>>>> pointer dereference, maybe they are related (or maybe not). Is it a >>>>>>> panic when bcache starts to run, or during heavy workload ? >>>>>> >>>>>> It's during heavy / normal workload. >>>>>> >>>>>>> If I may have chance to trigger similar oops on my server, that will be >>>>>>> much easier. So far I cannot reproduce any oops, neither by rebooting >>>>>>> and assemble bcache device by udev rules, nor compose bcache device and >>>>>>> run it by bash scripts... >>>>>> >>>>>> Do you need the line where this happens? It should be possible to get >>>>>> the line from the IP: [<ffffffffc04ef62e>] output? >>>>>> >>>>> This is very helpful. >>>> >>>> May be i'm too stupid but it does not print anything useful: >>>> >>>> # addr2line -f -e >>>> /usr/lib/debug/lib/modules/4.4.92+534-ph/kernel/drivers/md/bcache/bcache.ko >>>> ffffffffc04ef62e closure_sub >>>> ?? >>>> ??:0 >>>> bch_inc_gen >>>> ??:? >>>> >>>>> Is it possible to get a kdump crash for the kernel >>>>> oops, that will be much more informative :-) >>>> >>>> no idea how to archieve this for a remote Server. >>> >>> Hi Stefan, >>> >>> In code path of closure_wake_up(), I remember there are two patches in >>> last run, >>> - commit a5f3d8a5eaaf ("bcache: use llist_for_each_entry_safe() in >>> __closure_wake_up()") >>> - commit 09b3efec81de ("bcache: Don't reinvent the wheel but use >>> existing llist API") >>> >>> Can you check whether you have all of these patches ? Or can we try to >>> revoke these two patches and see whether oops still happens. >> >> It seems i'm missing a5f3d8a5eaaf but i have 09b3efec81de. >> >> I missed it because >> git log ..linux-block/for-next -- drivers/md/bcache/ >> >> does not show it. It seems linux-block/for-next does not contain it? >> Which branch should i use? >> >> Only those contain the mentioned commit: >> remotes/linux-block/for-linus >> remotes/linux-block/master >> remotes/linux-block/wbt-odirect >> > > Hi Stefan, > > These 2 patches are in 4.14 mainline kernel already. This is my fault to > make commit 09b3efec81de buggy, and fix it in commit a5f3d8a5eaaf. > > Could you please try again with the fixing patch ? > > (And I guess maybe other 2 reports may also miss this fix). OK indeed it seems it fixed it. Sorry about that. Greets, Stefan > Thanks. > > Coly Li > -- To unsubscribe from this list: send the line "unsubscribe linux-bcache" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html