On 13/03/10 03:05 PM, Rafael J. Wysocki wrote: > On Saturday 13 March 2010, M. Vefa Bicakci wrote: >> Hello, >> >> As you can guess from the subject, I have noticed that enabling the >> KMS feature of the i915 module with any kernel version after 2.6.32.7 >> causes memory corruption after one resumes from suspend-to-disk. >> >> My hardware is a Toshiba Satellite A100, with an Intel graphics card. >> I am using an up-to-date version of Debian Sid. Here are the lspci >> entries for my graphics card: >> >> === 8< === >> 00:02.0 VGA compatible controller [0300]: Intel Corporation Mobile 945GM/GMS, 943/940GML Express Integrated Graphics Controller [8086:27a2] (rev 03) (prog-if 00 [VGA controller]) >> 00:02.1 Display controller [0380]: Intel Corporation Mobile 945GM/GMS/GME, 943/940GML Express Integrated Graphics Controller [8086:27a6] (rev 03) >> === >8 === >> >> I have noticed that after upgrading from 2.6.32.7 to 2.6.32.9, I started >> to get a lot of segfaults from different programs when I resume from >> suspend-to-disk. After searching the Internet for this problem, I have >> seen that some other people also had it, and that it wasn't a new problem >> either: >> >> http://bbs.archlinux.org/viewtopic.php?id=91375 >> https://bugzilla.redhat.com/show_bug.cgi?id=537494 >> http://bugzilla.kernel.org/show_bug.cgi?id=13811 >> >> Even though some people say that they have had this problem for a long time, >> I have only noticed it after upgrading to 2.6.32.9. >> >> After booting with "nomodeset" and confirming that the problem doesn't >> happen with that kernel option, I have determined that the problem was >> with i915. >> >> Then I used the following command to bisect the changes that i915 has >> seen between 2.6.32.7 and 2.6.32.9: >> >> git bisect start v2.6.32.9 v2.6.32.7 -- ./drivers/gpu/drm/ >> >> With each iteration in the bisection, I have tried at least 3 cycles >> of suspend-to-disk and resume operations. I saw that all of the tried >> versions had memory corruption issues after resume from suspend-to-disk. >> >> Then, git told me that the culprit is the first change to i915 after the >> release 2.6.32.7. So 2.6.32.8 introduced the regression I am experiencing. >> Here's the "git bisect log" output: >> >> === 8< === >> # bad: [7f5e918e62cbc9ac27c2f47d3c3dd4b86f67ff0e] Linux 2.6.32.9 >> # good: [b4bdd73ce865213a5653dc424873e8da37e858cc] Linux 2.6.32.7 >> git bisect start 'v2.6.32.9' 'v2.6.32.7' '--' './drivers/gpu/drm/' >> # bad: [192ff23a2206eb5136c779bfed73171a4d214ad6] drm/i915: Add HP nx9020/SamsungSX20S to ACPI LID quirk list >> git bisect bad 192ff23a2206eb5136c779bfed73171a4d214ad6 >> # bad: [6240058ce3725f5e708e1c17c3a676217e44ba9b] drm/i915: disable hotplug detect before Ironlake CRT detect >> git bisect bad 6240058ce3725f5e708e1c17c3a676217e44ba9b >> # bad: [61d4374b51386dd40c03fd15df5a7f97347de688] drm/i915: Reload hangcheck timer too for Ironlake >> git bisect bad 61d4374b51386dd40c03fd15df5a7f97347de688 >> # bad: [d8e0902806c0bd2ccc4f6a267ff52565a3ec933b] drm/i915: Selectively enable self-reclaim >> git bisect bad d8e0902806c0bd2ccc4f6a267ff52565a3ec933b >> >> d8e0902806c0bd2ccc4f6a267ff52565a3ec933b is the first bad commit >> commit d8e0902806c0bd2ccc4f6a267ff52565a3ec933b >> Author: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> >> Date: Wed Jan 27 13:36:32 2010 +0000 >> >> drm/i915: Selectively enable self-reclaim >> >> commit 4bdadb9785696439c6e2b3efe34aa76df1149c83 upstream. >> >> Having missed the ENOMEM return via i915_gem_fault(), there are probably >> other paths that I also missed. By not enabling NORETRY by default these >> paths can run the shrinker and take memory from the system (but not from >> our own inactive lists because our shrinker can not run whilst we hold >> the struct mutex) and this may allow the system to survive a little longer >> whilst our drivers consume all available memory. >> >> References: >> OOM killer unexpectedly called with kernel 2.6.32 >> http://bugzilla.kernel.org/show_bug.cgi?id=14933 >> >> v2: Pass gfp into page mapping. >> v3: Use new read_cache_page_gfp() instead of open-coding. >> >> ... >> === >8 === >> >> For the record, just to confirm that this commit is actually the culprit, >> I took a vanilla 2.6.32.9 source tree and reverted only this commit. I am >> happy to let you know that with this commit reverted, I can no longer >> reproduce the memory corruption issue. >> >> However, as I noted above, some people have had this problem for a longer >> time. So I am not sure if the commit above causes the bug or if it makes >> the bug easier to trigger. >> >> Finally, I would like to note that this regression is going to be important, >> because, as you know, Intel's X11 drivers are not going to support mode-setting >> in user mode starting with version 2.10.0. >> >> If there is any help I can provide in fixing this regression, please let me >> know. I am willing to try patches. > > If I remember correctly, this has been fixed in the mainline, but I don't > remember the exact commit right now. > > Chris, Jesse, can you please help? > > Rafael Dear Rafael Wysocki, I am sorry for the late reply. When you said that this problem had been fixed in mainline, I thought that you meant the 2.6.34-rcX series, because I had already tested 2.6.33 before sending my original e-mail and confirmed that it had this problem as well. So, with the hope of seeing this problem fixed, I tried git commit a3d3203e4bb40f253b1541e310dc0f9305be7c84 (which happens to be the most recent version in the git repository as of a few hours ago) but I am sorry to let you know that the problem persists. After I resume from suspend to disk with this version, I still get a lot of segfaults from newly started programs. As I have mentioned in my original e-mail (which I left intact above), I have already done a bisection and identified the git commit which introduced this problem. I believe that this is an important regression, and I know of at least three more people who are affected by this problem. If I remember correctly, you made a list of known regressions. Would it be possible to create an entry in the list for this bug, so that this regression will hopefully get more attention? I would appreciate any help. Regards, M. Vefa Bicakci _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
