linux-kernel - Re: [Bisected Regression in 2.6.35] A full tmpfs filesystem causeshibernation to hang

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Date:	Tue, 31 Aug 2010 15:35:32 +0900 (JST)
From:	KOSAKI Motohiro <kosaki.motohiro@...fujitsu.com>
To:	"M. Vefa Bicakci" <bicave@...eronline.com>
Cc:	kosaki.motohiro@...fujitsu.com,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [Bisected Regression in 2.6.35] A full tmpfs filesystem causeshibernation to hang

> On 30/08/10 05:28 AM, KOSAKI Motohiro wrote:
> >> [snip]
> >>
> >> The interesting thing is that even though there is a lot of free memory at the
> >> end, it still hangs. 
> > 
> > Grr. I'm surprised this result ;-)
> > shrink_all_memory() finish to shrink memory successfully. but your
> > system still hang immediately after. I have no idea why this mysterious
> > occur. 
> > 
> > I prepared next debugging patch. It added prenty debug printk. I hope
> > it enlighten up which path makes system hang-up.
> > 
> > 1. apply my new patch
> > 
> > 2. Enable following PM debug option in Kconfig
> > 
> >   [*] Power Management support
> >   [*]   Power Management Debug Support
> >   [*]     Extra PM attributes in sysfs for low-level debugging/testing
> >   [*]     Verbose Power Management debugging
> > 
> > 3. append following kernel boot option into grub configration file
> > 
> > 	no_console_suspend=1
> > 
> > 3. kernel build and reboot
> > 4. some prepare
> >    # echo 8 > /proc/sysrq-trigger
> >    # cd /sys/power
> >    # echo 1 > pm_trace
> >    # echo 0 > pm_async
> > 
> > 5. run your test program
> > 
> > 
> >> I also included the timestamps; note the one and two second
> >> delays between the passes.
> > 
> > This is expected result because tmpfs shrink need swap-out. then
> > we need i/o time.
> > 
> >>
> >> Please let me know if there is anything I can do.
> > 
> > Please send me your .config and full dmesg.
> > 
> > 
> > Thanks many and many help us!
> 
> Hello,
> 
> I have followed your instructions, with one exception: I have also
> enabled CONFIG_PM_TRACE so that I would have /sys/power/pm_trace.
> 
> This time I had some more output, as expected. I double checked what
> I typed while looking at the screen-shot I took with my camera. Here's
> the output:
> 
> === 8< ===
> PM: Marking nosave pages: ...0009f000 - ...000100000
> PM: basic memory bitmaps created
> PM: Syncing filesystems ... done
> Freezing user space processes ... (elapsed 0.01 seconds) done.
> Freezing remaining freezable tasks ... (elapsed 0.01 seconds) done.
> PM: Preallocating image memory...
> shrink_all_memory start
> PM: shrink memory: pass=1, req:310171 reclaimed:15492 free:360936
> PM: shrink memory: pass=2, req:294679 reclaimed:28864 free:373981
> PM: shrink memory: pass=3, req:265815 reclaimed:60311 free:405374
> PM: shrink memory: pass=4, req:205504 reclaimed:97870 free:443024
> PM: shrink memory: pass=5, req:107634 reclaimed:146948 free:492141
> shrink_all_memory: req:107634 reclaimed:146948 free:492141
> PM: preallocate_image_highmem 556658 278329
> PM: preallocate_image_memory 103139 103139
> PM: preallocate_highmem_fraction 183908 556658 760831 -> 183908
> === >8 ===
> 
> According to your patch, the next output should have been
> "preallocate_image_memory ...", but it never gets printed, so the
> hang point should be that function.

Great!
I've attached more verbose debug message patch and trial bug fixing patch.
Could you please to try this?



> I am attaching my dmesg output which I got after the failed hibernation
> attempt and my .config file. Please note that the attached .config file
> is a trimmed version of the .config I usually use on my computer. I trimmed
> it so that it compiles faster, but (mostly) has support for devices I might
> use.
> 
> Thanks a lot for your help, and please let me know if I can do anything else.
> 


Download attachment "0001-debug2.patch" of type "application/octet-stream" (5261 bytes)

Download attachment "0002-add-gfp_noretry.patch" of type "application/octet-stream" (825 bytes)