LinuxLists.cc - [Bisected Regression in 2.6.35] A full tmpfs filesystem causes hibernationto hang

2010-08-15 05:25:47

Subject: [Bisected Regression in 2.6.35] A full tmpfs filesystem causes hibernationto hang

Hello all,

I am using Debian Sid on a Toshiba Satellite A100 laptop. After testing
2.6.35 for a while, I noticed that sometimes my hibernation attempts
would fail. I should say that I never had such a problem before 2.6.35.
The hibernation process hangs with 2.6.35 after printing the following:

=== 8< ===
...
Freezing remaining freezable tasks ... (elapsed 0.01 seconds) done.
PM: Preallocating image memory...
=== >8 ===

After a short investigation, I found out that this only happens when my
tmpfs filesystem on /tmp had a lot of data in it. When my tmpfs is empty,
I have no problems.

So I wrote a short script which fills up the tmpfs on /tmp and tries to
hibernate, and I bisected the kernel using this script.

The end result is that the following commit causes this regression:

=== 8< ===
commit bb21c7ce18eff8e6e7877ca1d06c6db719376e3c
Author: KOSAKI Motohiro <[email protected]>
Date: Fri Jun 4 14:15:05 2010 -0700

vmscan: fix do_try_to_free_pages() return value when priority==0 reclaim failure

...
=== >8 ===

I have run 2.6.35-rc6, 2.6.35 and 2.6.35.1 with this commit reverted,
and I am happy to say that I haven't experienced any problems for at
least 17 days.

It looks like this change was included with 2.6.35-rc1. I am sorry
for not testing earlier.

I am willing to do testing in case anyone would like me to try patches.

Regards,

M. Vefa Bicakci

2010-08-17 02:37:44

by KOSAKI Motohiro

[permalink] [raw]

Subject: Re: [Bisected Regression in 2.6.35] A full tmpfs filesystem causes hibernationto hang

> Hello all,
>
> I am using Debian Sid on a Toshiba Satellite A100 laptop. After testing
> 2.6.35 for a while, I noticed that sometimes my hibernation attempts
> would fail. I should say that I never had such a problem before 2.6.35.
> The hibernation process hangs with 2.6.35 after printing the following:
>
> === 8< ===
> ...
> Freezing remaining freezable tasks ... (elapsed 0.01 seconds) done.
> PM: Preallocating image memory...
> === >8 ===
>
> After a short investigation, I found out that this only happens when my
> tmpfs filesystem on /tmp had a lot of data in it. When my tmpfs is empty,
> I have no problems.
>
> So I wrote a short script which fills up the tmpfs on /tmp and tries to
> hibernate, and I bisected the kernel using this script.
>
> The end result is that the following commit causes this regression:
>
> === 8< ===
> commit bb21c7ce18eff8e6e7877ca1d06c6db719376e3c
> Author: KOSAKI Motohiro <[email protected]>
> Date: Fri Jun 4 14:15:05 2010 -0700
>
> vmscan: fix do_try_to_free_pages() return value when priority==0 reclaim failure
>
> ...
> === >8 ===
>
> I have run 2.6.35-rc6, 2.6.35 and 2.6.35.1 with this commit reverted,
> and I am happy to say that I haven't experienced any problems for at
> least 17 days.
>
> It looks like this change was included with 2.6.35-rc1. I am sorry
> for not testing earlier.
>
> I am willing to do testing in case anyone would like me to try patches.

Wow.

I'm very surprised this report because 1) the above commit changed
do_try_to_free_pages() return value 2) but current hibernation code is
ignoring this return value. Hmm... I have to investigate this very
interesting issue.

Thanks this report, and please give me a bit time.

2010-08-22 11:06:32

On Wednesday, August 25, 2010, KOSAKI Motohiro wrote:
> > > % cat /proc/meminfo
> >
> > MemTotal: 3104484 kB
> > MemFree: 2817616 kB
> > Buffers: 31156 kB
> > Cached: 142124 kB
> > SwapCached: 0 kB
> > Active: 116464 kB
> > Inactive: 137424 kB
> > Active(anon): 80852 kB
> > Inactive(anon): 24820 kB
> > Active(file): 35612 kB
> > Inactive(file): 112604 kB
> > Unevictable: 32 kB
> > Mlocked: 32 kB
> > HighTotal: 2226632 kB
> > HighFree: 1994008 kB
> > LowTotal: 877852 kB
> > LowFree: 823608 kB
> > SwapTotal: 1999540 kB
> > SwapFree: 1999540 kB
>
> !! Your swap partition is smaller than physical memory. As far as I know,
> swap partition need physcal-mem x 2 size. Can you please try to change
> swap configuration?
>
> Rafael, please correct me if I'm talking wrong.

No, we only save 50% of RAM (at most) during hibernation.

Thanks,
Rafael