Hi Baoquan, To which commit should we apply the draft patch. We tried applying the patch to the commit 3e4fb4346c781068610d03c12b16c0cfb0fd24a3 (the one we used for applying the previous patch) but it fails. From: bhe@xxxxxxxxxx <bhe@xxxxxxxxxx> Sent: 12 November 2020 8:21 PM To: Rahul Gopakumar <gopakumarr@xxxxxxxxxx> Cc: linux-mm@xxxxxxxxx <linux-mm@xxxxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx <linux-kernel@xxxxxxxxxxxxxxx>; akpm@xxxxxxxxxxxxxxxxxxxx <akpm@xxxxxxxxxxxxxxxxxxxx>; natechancellor@xxxxxxxxx <natechancellor@xxxxxxxxx>; ndesaulniers@xxxxxxxxxx <ndesaulniers@xxxxxxxxxx>; clang-built-linux@xxxxxxxxxxxxxxxx <clang-built-linux@xxxxxxxxxxxxxxxx>; rostedt@xxxxxxxxxxx <rostedt@xxxxxxxxxxx>; Rajender M <manir@xxxxxxxxxx>; Yiu Cho Lau <lauyiuch@xxxxxxxxxx>; Peter Jonasson <pjonasson@xxxxxxxxxx>; Venkatesh Rajaram <rajaramv@xxxxxxxxxx> Subject: Re: Performance regressions in "boot_time" tests in Linux 5.8 Kernel On 11/03/20 at 12:34pm, Rahul Gopakumar wrote: > >> So, you mean with the draft patch applied, the initial performance > regression goes away, just many page corruption errors with call trace > are seen, right? > > Yes, that's right. > > >> And the performance regression is about 2sec delay in > your system? > > The delay due to this new page corruption issue is about > 3 secs. > > Here is the summary > > * Initial problem - 2 secs > * Draft patch - Fixes initial problem (recovers 2 secs) but > brings in new page corruption issue (3 secs) > > >> Could you tell how you setup vmware VM so that I can ask our QA for > help to create a vmware VM for me to test? > > * Use vSphere ESXi 6.7 or 7.0 GA. > * Create VM using vSphere Web Client and specify 1TB VM Memory. > * Install RHEL 8.1, that's the guest used in this test. Can you try the attached draft patch? > > With draft patch, you should be able to reproduce the issue. > Let me know if you need more details.
