(cc linux-mm, argh) On Fri, 12 Oct 2018 15:55:33 -0700 Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > > (switched to email. Please respond via emailed reply-to-all, not via the > bugzilla web interface). > > Vlastimil, it looks like your August 21 smaps changes are failing. > This one is pretty urgent, please. > > Leonardo (yes?): thanks for reporting. Very helpful. > > On Thu, 11 Oct 2018 18:13:31 +0000 bugzilla-daemon@xxxxxxxxxxxxxxxxxxx wrote: > > > https://bugzilla.kernel.org/show_bug.cgi?id=201377 > > > > Bug ID: 201377 > > Summary: Kernel BUG under memory pressure: unable to handle > > kernel NULL pointer dereference at 00000000000000f0 > > Product: Memory Management > > Version: 2.5 > > Kernel Version: 4.19-rc7 > > Hardware: All > > OS: Linux > > Tree: Mainline > > Status: NEW > > Severity: normal > > Priority: P1 > > Component: Other > > Assignee: akpm@xxxxxxxxxxxxxxxxxxxx > > Reporter: leozinho29_eu@xxxxxxxxxxx > > Regression: No > > > > Created attachment 278997 > > --> https://bugzilla.kernel.org/attachment.cgi?id=278997&action=edit > > dmesg and kernel config > > > > I'm using Xubuntu 18.04 and I noticed that under memory pressure the script > > from https://github.com/pixelb/ps_mem.git (HEAD > > 1ed0bc5519d889d58235f2c35db01e4ede0d8231is) causing a kernel BUG and locking a > > CPU. On dmesg the following appears: > > > > BUG: unable to handle kernel NULL pointer dereference at 00000000000000f0 > > > > After this BUG the computer performance becomes greatly degraded, some software > > do not close, some fail to open, some fail to work properly. As an example, > > bash fails to autocomplete. > > > > Steps to reproduce: > > > > 1) Be under memory pressure. Using dd to write a large file at /dev/shm works > > for this; > > 2) Run the script from https://github.com/pixelb/ps_mem.git > > > > Expected result: script will print information and system will keep working > > normally; > > > > Observed result: script is killed, kernel BUG happens, CPU get stuck and > > computer presents problems. > > > > I did not observe this with 4.17.19, I'll bisect and see if I can find which > > commit is causing this. > > > > I'm sorry if I'm reporting to the wrong product and component. > > > > -- > > You are receiving this mail because: > > You are the assignee for the bug.
