Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-22 Thread Michal Hocko
[Sorry for the late reply, I was mostly offline throughout last week] On Tue 16-09-14 15:55:48, Cong Wang wrote: > On Mon, Sep 15, 2014 at 2:36 AM, Michal Hocko wrote: > > This patch builds on top of Cong Wang's. What do you think? > > I think it is should a preliminary of my patch, not a

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-22 Thread Michal Hocko
[Sorry for the late reply, I was mostly offline throughout last week] On Tue 16-09-14 15:55:48, Cong Wang wrote: On Mon, Sep 15, 2014 at 2:36 AM, Michal Hocko mho...@suse.cz wrote: This patch builds on top of Cong Wang's. What do you think? I think it is should a preliminary of my patch,

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-16 Thread Cong Wang
On Mon, Sep 15, 2014 at 4:22 AM, Michal Hocko wrote: > On Thu 04-09-14 15:30:41, Cong Wang wrote: >> There is a race condition between OOM killer and freezer when >> they try to operate on the same process, something like below: >> >> Process A Process B Process C >>

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-16 Thread Cong Wang
On Mon, Sep 15, 2014 at 2:36 AM, Michal Hocko wrote: > This patch builds on top of Cong Wang's. What do you think? I think it is should a preliminary of my patch, not a followup. I can carry this patch for you if you want. > --- > From cdf97a20b107ee584352f07274a88d7c3f014ab2 Mon Sep 17

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-16 Thread Cong Wang
On Mon, Sep 15, 2014 at 2:36 AM, Michal Hocko mho...@suse.cz wrote: This patch builds on top of Cong Wang's. What do you think? I think it is should a preliminary of my patch, not a followup. I can carry this patch for you if you want. --- From cdf97a20b107ee584352f07274a88d7c3f014ab2 Mon Sep

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-16 Thread Cong Wang
On Mon, Sep 15, 2014 at 4:22 AM, Michal Hocko mho...@suse.cz wrote: On Thu 04-09-14 15:30:41, Cong Wang wrote: There is a race condition between OOM killer and freezer when they try to operate on the same process, something like below: Process A Process B Process C

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-15 Thread Tejun Heo
Hello, Michal. On Mon, Sep 15, 2014 at 04:28:21PM +0200, Michal Hocko wrote: > > Are we gonna introduce an alternate versions for all of them? > > Are they intended for kernel threads in the first place? The primary There's no restriction in using them and I'm pretty sure some of them are used

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-15 Thread Michal Hocko
On Sat 13-09-14 08:48:46, Tejun Heo wrote: > Hello, Michal. > > On Wed, Sep 10, 2014 at 03:24:17PM +0200, Michal Hocko wrote: > > What do you think about this way to help distinguish kernel threads and > > user processes and keep the future maintenance of freezer saner? > > I'm not sure either

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-15 Thread Michal Hocko
On Thu 04-09-14 15:30:41, Cong Wang wrote: > There is a race condition between OOM killer and freezer when > they try to operate on the same process, something like below: > > Process A Process B Process C > trigger page fault > then trigger oom >

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-15 Thread Michal Hocko
On Mon 15-09-14 05:34:36, Rafael J. Wysocki wrote: > On Monday, September 15, 2014 09:56:57 AM Tejun Heo wrote: > > On Sun, Sep 14, 2014 at 06:43:31PM +0200, Rafael J. Wysocki wrote: > > > On Saturday, September 13, 2014 08:59:35 AM Tejun Heo wrote: > > > > Doesn't this mean that if PM freezing

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-15 Thread Michal Hocko
On Mon 15-09-14 05:34:36, Rafael J. Wysocki wrote: On Monday, September 15, 2014 09:56:57 AM Tejun Heo wrote: On Sun, Sep 14, 2014 at 06:43:31PM +0200, Rafael J. Wysocki wrote: On Saturday, September 13, 2014 08:59:35 AM Tejun Heo wrote: Doesn't this mean that if PM freezing and OOM

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-15 Thread Michal Hocko
On Thu 04-09-14 15:30:41, Cong Wang wrote: There is a race condition between OOM killer and freezer when they try to operate on the same process, something like below: Process A Process B Process C trigger page fault then trigger oom B=oom_scan_process_thread()

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-15 Thread Michal Hocko
On Sat 13-09-14 08:48:46, Tejun Heo wrote: Hello, Michal. On Wed, Sep 10, 2014 at 03:24:17PM +0200, Michal Hocko wrote: What do you think about this way to help distinguish kernel threads and user processes and keep the future maintenance of freezer saner? I'm not sure either way.

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-15 Thread Tejun Heo
Hello, Michal. On Mon, Sep 15, 2014 at 04:28:21PM +0200, Michal Hocko wrote: Are we gonna introduce an alternate versions for all of them? Are they intended for kernel threads in the first place? The primary There's no restriction in using them and I'm pretty sure some of them are used by

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-14 Thread Rafael J. Wysocki
On Monday, September 15, 2014 09:56:57 AM Tejun Heo wrote: > On Sun, Sep 14, 2014 at 06:43:31PM +0200, Rafael J. Wysocki wrote: > > On Saturday, September 13, 2014 08:59:35 AM Tejun Heo wrote: > > > Doesn't this mean that if PM freezing and OOM killing race each other, > > > the system may hang?

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-14 Thread Tejun Heo
On Sun, Sep 14, 2014 at 06:43:31PM +0200, Rafael J. Wysocki wrote: > On Saturday, September 13, 2014 08:59:35 AM Tejun Heo wrote: > > Doesn't this mean that if PM freezing and OOM killing race each other, > > the system may hang? Driver PM operation may try to allocate memory > > -> triggers OOM

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-14 Thread Rafael J. Wysocki
On Saturday, September 13, 2014 08:59:35 AM Tejun Heo wrote: > On Thu, Sep 11, 2014 at 06:30:04PM +0200, Michal Hocko wrote: > > > I am wondering if the folllowing check makes any sense with regarding > > > to rule out PM freeze: > > > > > > if ((!pm_nosig_freezing && !pm_freezing) && > >

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-14 Thread Rafael J. Wysocki
On Thursday, September 11, 2014 04:45:09 PM Michal Hocko wrote: > On Thu 11-09-14 16:52:50, Rafael J. Wysocki wrote: > > On Thursday, September 11, 2014 04:28:22 PM Michal Hocko wrote: > > > On Thu 11-09-14 16:32:50, Rafael J. Wysocki wrote: > > > > On Thursday, September 11, 2014 04:10:51 PM

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-14 Thread Rafael J. Wysocki
On Thursday, September 11, 2014 04:45:09 PM Michal Hocko wrote: On Thu 11-09-14 16:52:50, Rafael J. Wysocki wrote: On Thursday, September 11, 2014 04:28:22 PM Michal Hocko wrote: On Thu 11-09-14 16:32:50, Rafael J. Wysocki wrote: On Thursday, September 11, 2014 04:10:51 PM Michal Hocko

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-14 Thread Rafael J. Wysocki
On Saturday, September 13, 2014 08:59:35 AM Tejun Heo wrote: On Thu, Sep 11, 2014 at 06:30:04PM +0200, Michal Hocko wrote: I am wondering if the folllowing check makes any sense with regarding to rule out PM freeze: if ((!pm_nosig_freezing !pm_freezing)

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-14 Thread Tejun Heo
On Sun, Sep 14, 2014 at 06:43:31PM +0200, Rafael J. Wysocki wrote: On Saturday, September 13, 2014 08:59:35 AM Tejun Heo wrote: Doesn't this mean that if PM freezing and OOM killing race each other, the system may hang? Driver PM operation may try to allocate memory - triggers OOM - OOM

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-14 Thread Rafael J. Wysocki
On Monday, September 15, 2014 09:56:57 AM Tejun Heo wrote: On Sun, Sep 14, 2014 at 06:43:31PM +0200, Rafael J. Wysocki wrote: On Saturday, September 13, 2014 08:59:35 AM Tejun Heo wrote: Doesn't this mean that if PM freezing and OOM killing race each other, the system may hang? Driver PM

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-12 Thread Tejun Heo
On Thu, Sep 11, 2014 at 06:30:04PM +0200, Michal Hocko wrote: > > I am wondering if the folllowing check makes any sense with regarding > > to rule out PM freeze: > > > > if ((!pm_nosig_freezing && !pm_freezing) && > > cgroup_freezing(current) && test_thread_flag(TIF_MEMDIE))

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-12 Thread Tejun Heo
Hello, Michal. On Wed, Sep 10, 2014 at 03:24:17PM +0200, Michal Hocko wrote: > What do you think about this way to help distinguish kernel threads and > user processes and keep the future maintenance of freezer saner? I'm not sure either way. Please note that we have quite a few wrappers around

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-12 Thread Tejun Heo
Hello, Michal. On Wed, Sep 10, 2014 at 03:24:17PM +0200, Michal Hocko wrote: What do you think about this way to help distinguish kernel threads and user processes and keep the future maintenance of freezer saner? I'm not sure either way. Please note that we have quite a few wrappers around

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-12 Thread Tejun Heo
On Thu, Sep 11, 2014 at 06:30:04PM +0200, Michal Hocko wrote: I am wondering if the folllowing check makes any sense with regarding to rule out PM freeze: if ((!pm_nosig_freezing !pm_freezing) cgroup_freezing(current) test_thread_flag(TIF_MEMDIE))

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-11 Thread Michal Hocko
On Wed 10-09-14 13:30:25, Cong Wang wrote: > On Mon, Sep 8, 2014 at 4:29 PM, Cong Wang wrote: > > On Mon, Sep 8, 2014 at 4:42 PM, Rafael J. Wysocki > > wrote: > >> On Monday, September 08, 2014 04:16:15 PM Cong Wang wrote: > >>> On Mon, Sep 8, 2014 at 4:23 PM, Rafael J. Wysocki > >>> wrote: >

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-11 Thread Michal Hocko
On Thu 11-09-14 16:52:50, Rafael J. Wysocki wrote: > On Thursday, September 11, 2014 04:28:22 PM Michal Hocko wrote: > > On Thu 11-09-14 16:32:50, Rafael J. Wysocki wrote: > > > On Thursday, September 11, 2014 04:10:51 PM Michal Hocko wrote: > > > > On Thu 11-09-14 16:26:56, Rafael J. Wysocki

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-11 Thread Rafael J. Wysocki
On Thursday, September 11, 2014 04:28:22 PM Michal Hocko wrote: > On Thu 11-09-14 16:32:50, Rafael J. Wysocki wrote: > > On Thursday, September 11, 2014 04:10:51 PM Michal Hocko wrote: > > > On Thu 11-09-14 16:26:56, Rafael J. Wysocki wrote: > > > > On Thursday, September 11, 2014 04:04:48 PM

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-11 Thread Michal Hocko
On Thu 11-09-14 16:32:50, Rafael J. Wysocki wrote: > On Thursday, September 11, 2014 04:10:51 PM Michal Hocko wrote: > > On Thu 11-09-14 16:26:56, Rafael J. Wysocki wrote: > > > On Thursday, September 11, 2014 04:04:48 PM Michal Hocko wrote: > > > > On Thu 11-09-14 16:17:56, Rafael J. Wysocki

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-11 Thread Rafael J. Wysocki
On Thursday, September 11, 2014 04:10:51 PM Michal Hocko wrote: > On Thu 11-09-14 16:26:56, Rafael J. Wysocki wrote: > > On Thursday, September 11, 2014 04:04:48 PM Michal Hocko wrote: > > > On Thu 11-09-14 16:17:56, Rafael J. Wysocki wrote: > > > [...] > > > > And I'm still wondering if the OOM

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-11 Thread Michal Hocko
On Thu 11-09-14 16:17:56, Rafael J. Wysocki wrote: [...] > And I'm still wondering if the OOM killer may be made avoid killing frozen > tasks. This is really tricky. OOM killer aims at the biggest memory hog. We shouldn't ignore it just because it hides into the fridge... So even if we "fix" oom

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-11 Thread Michal Hocko
On Thu 11-09-14 16:26:56, Rafael J. Wysocki wrote: > On Thursday, September 11, 2014 04:04:48 PM Michal Hocko wrote: > > On Thu 11-09-14 16:17:56, Rafael J. Wysocki wrote: > > [...] > > > And I'm still wondering if the OOM killer may be made avoid killing frozen > > > tasks. > > > > This is

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-11 Thread Rafael J. Wysocki
On Thursday, September 11, 2014 04:04:48 PM Michal Hocko wrote: > On Thu 11-09-14 16:17:56, Rafael J. Wysocki wrote: > [...] > > And I'm still wondering if the OOM killer may be made avoid killing frozen > > tasks. > > This is really tricky. OOM killer aims at the biggest memory hog. We >

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-11 Thread Rafael J. Wysocki
On Thursday, September 11, 2014 03:08:40 PM Michal Hocko wrote: > On Wed 10-09-14 15:24:17, Michal Hocko wrote: > > On Tue 09-09-14 22:53:32, Rafael J. Wysocki wrote: > > > On Wednesday, September 10, 2014 01:46:58 AM Tejun Heo wrote: > > > > Hello, > > > > > > > > On Tue, Sep 09, 2014 at

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-11 Thread Michal Hocko
On Wed 10-09-14 15:24:17, Michal Hocko wrote: > On Tue 09-09-14 22:53:32, Rafael J. Wysocki wrote: > > On Wednesday, September 10, 2014 01:46:58 AM Tejun Heo wrote: > > > Hello, > > > > > > On Tue, Sep 09, 2014 at 06:06:25PM +0200, Michal Hocko wrote: > > > > > Even for userland tasks,

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-11 Thread Michal Hocko
On Wed 10-09-14 15:24:17, Michal Hocko wrote: On Tue 09-09-14 22:53:32, Rafael J. Wysocki wrote: On Wednesday, September 10, 2014 01:46:58 AM Tejun Heo wrote: Hello, On Tue, Sep 09, 2014 at 06:06:25PM +0200, Michal Hocko wrote: Even for userland tasks, try_to_freeze() can

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-11 Thread Rafael J. Wysocki
On Thursday, September 11, 2014 03:08:40 PM Michal Hocko wrote: On Wed 10-09-14 15:24:17, Michal Hocko wrote: On Tue 09-09-14 22:53:32, Rafael J. Wysocki wrote: On Wednesday, September 10, 2014 01:46:58 AM Tejun Heo wrote: Hello, On Tue, Sep 09, 2014 at 06:06:25PM +0200, Michal

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-11 Thread Rafael J. Wysocki
On Thursday, September 11, 2014 04:04:48 PM Michal Hocko wrote: On Thu 11-09-14 16:17:56, Rafael J. Wysocki wrote: [...] And I'm still wondering if the OOM killer may be made avoid killing frozen tasks. This is really tricky. OOM killer aims at the biggest memory hog. We shouldn't ignore

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-11 Thread Michal Hocko
On Thu 11-09-14 16:26:56, Rafael J. Wysocki wrote: On Thursday, September 11, 2014 04:04:48 PM Michal Hocko wrote: On Thu 11-09-14 16:17:56, Rafael J. Wysocki wrote: [...] And I'm still wondering if the OOM killer may be made avoid killing frozen tasks. This is really tricky. OOM

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-11 Thread Michal Hocko
On Thu 11-09-14 16:17:56, Rafael J. Wysocki wrote: [...] And I'm still wondering if the OOM killer may be made avoid killing frozen tasks. This is really tricky. OOM killer aims at the biggest memory hog. We shouldn't ignore it just because it hides into the fridge... So even if we fix oom

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-11 Thread Rafael J. Wysocki
On Thursday, September 11, 2014 04:10:51 PM Michal Hocko wrote: On Thu 11-09-14 16:26:56, Rafael J. Wysocki wrote: On Thursday, September 11, 2014 04:04:48 PM Michal Hocko wrote: On Thu 11-09-14 16:17:56, Rafael J. Wysocki wrote: [...] And I'm still wondering if the OOM killer may be

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-11 Thread Michal Hocko
On Thu 11-09-14 16:32:50, Rafael J. Wysocki wrote: On Thursday, September 11, 2014 04:10:51 PM Michal Hocko wrote: On Thu 11-09-14 16:26:56, Rafael J. Wysocki wrote: On Thursday, September 11, 2014 04:04:48 PM Michal Hocko wrote: On Thu 11-09-14 16:17:56, Rafael J. Wysocki wrote:

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-11 Thread Rafael J. Wysocki
On Thursday, September 11, 2014 04:28:22 PM Michal Hocko wrote: On Thu 11-09-14 16:32:50, Rafael J. Wysocki wrote: On Thursday, September 11, 2014 04:10:51 PM Michal Hocko wrote: On Thu 11-09-14 16:26:56, Rafael J. Wysocki wrote: On Thursday, September 11, 2014 04:04:48 PM Michal Hocko

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-11 Thread Michal Hocko
On Thu 11-09-14 16:52:50, Rafael J. Wysocki wrote: On Thursday, September 11, 2014 04:28:22 PM Michal Hocko wrote: On Thu 11-09-14 16:32:50, Rafael J. Wysocki wrote: On Thursday, September 11, 2014 04:10:51 PM Michal Hocko wrote: On Thu 11-09-14 16:26:56, Rafael J. Wysocki wrote: On

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-11 Thread Michal Hocko
On Wed 10-09-14 13:30:25, Cong Wang wrote: On Mon, Sep 8, 2014 at 4:29 PM, Cong Wang xiyou.wangc...@gmail.com wrote: On Mon, Sep 8, 2014 at 4:42 PM, Rafael J. Wysocki r...@rjwysocki.net wrote: On Monday, September 08, 2014 04:16:15 PM Cong Wang wrote: On Mon, Sep 8, 2014 at 4:23 PM,

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-10 Thread Cong Wang
On Wed, Sep 10, 2014 at 4:38 PM, Rafael J. Wysocki wrote: > On Wednesday, September 10, 2014 01:30:25 PM Cong Wang wrote: >> I am wondering if the folllowing check makes any sense with regarding >> to rule out PM freeze: >> >> if ((!pm_nosig_freezing && !pm_freezing) && >>

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-10 Thread Rafael J. Wysocki
On Wednesday, September 10, 2014 01:30:25 PM Cong Wang wrote: > On Mon, Sep 8, 2014 at 4:29 PM, Cong Wang wrote: > > On Mon, Sep 8, 2014 at 4:42 PM, Rafael J. Wysocki > > wrote: > >> On Monday, September 08, 2014 04:16:15 PM Cong Wang wrote: > >>> On Mon, Sep 8, 2014 at 4:23 PM, Rafael J.

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-10 Thread Cong Wang
On Mon, Sep 8, 2014 at 4:29 PM, Cong Wang wrote: > On Mon, Sep 8, 2014 at 4:42 PM, Rafael J. Wysocki wrote: >> On Monday, September 08, 2014 04:16:15 PM Cong Wang wrote: >>> On Mon, Sep 8, 2014 at 4:23 PM, Rafael J. Wysocki >>> wrote: >>> > >>> > The reason why it matters for the suspend-time

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-10 Thread Michal Hocko
On Tue 09-09-14 22:53:32, Rafael J. Wysocki wrote: > On Wednesday, September 10, 2014 01:46:58 AM Tejun Heo wrote: > > Hello, > > > > On Tue, Sep 09, 2014 at 06:06:25PM +0200, Michal Hocko wrote: > > > > Even for userland tasks, try_to_freeze() can currently be anywhere in > > > > the kernel.

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-10 Thread Michal Hocko
On Tue 09-09-14 22:53:32, Rafael J. Wysocki wrote: On Wednesday, September 10, 2014 01:46:58 AM Tejun Heo wrote: Hello, On Tue, Sep 09, 2014 at 06:06:25PM +0200, Michal Hocko wrote: Even for userland tasks, try_to_freeze() can currently be anywhere in the kernel. The frequently

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-10 Thread Cong Wang
On Mon, Sep 8, 2014 at 4:29 PM, Cong Wang xiyou.wangc...@gmail.com wrote: On Mon, Sep 8, 2014 at 4:42 PM, Rafael J. Wysocki r...@rjwysocki.net wrote: On Monday, September 08, 2014 04:16:15 PM Cong Wang wrote: On Mon, Sep 8, 2014 at 4:23 PM, Rafael J. Wysocki r...@rjwysocki.net wrote: The

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-10 Thread Rafael J. Wysocki
On Wednesday, September 10, 2014 01:30:25 PM Cong Wang wrote: On Mon, Sep 8, 2014 at 4:29 PM, Cong Wang xiyou.wangc...@gmail.com wrote: On Mon, Sep 8, 2014 at 4:42 PM, Rafael J. Wysocki r...@rjwysocki.net wrote: On Monday, September 08, 2014 04:16:15 PM Cong Wang wrote: On Mon, Sep 8,

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-10 Thread Cong Wang
On Wed, Sep 10, 2014 at 4:38 PM, Rafael J. Wysocki r...@rjwysocki.net wrote: On Wednesday, September 10, 2014 01:30:25 PM Cong Wang wrote: I am wondering if the folllowing check makes any sense with regarding to rule out PM freeze: if ((!pm_nosig_freezing !pm_freezing)

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-09 Thread Cong Wang
On Tue, Sep 9, 2014 at 1:48 PM, Rafael J. Wysocki wrote: > On Wednesday, September 10, 2014 12:23:36 AM Tejun Heo wrote: >> On Tue, Sep 09, 2014 at 05:16:55PM +0200, Michal Hocko wrote: >> > But OOM killer doesn't kill kernel threads as they do not own any >> > memory. So the check should be

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-09 Thread Rafael J. Wysocki
On Wednesday, September 10, 2014 01:46:58 AM Tejun Heo wrote: > Hello, > > On Tue, Sep 09, 2014 at 06:06:25PM +0200, Michal Hocko wrote: > > > Even for userland tasks, try_to_freeze() can currently be anywhere in > > > the kernel. The frequently used ones are few but there are some odd > > > >

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-09 Thread Rafael J. Wysocki
On Wednesday, September 10, 2014 12:23:36 AM Tejun Heo wrote: > On Tue, Sep 09, 2014 at 05:16:55PM +0200, Michal Hocko wrote: > > But OOM killer doesn't kill kernel threads as they do not own any > > memory. So the check should be safe, no? > > Even for userland tasks, try_to_freeze() can

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-09 Thread Michal Hocko
On Wed 10-09-14 01:46:58, Tejun Heo wrote: > Hello, > > On Tue, Sep 09, 2014 at 06:06:25PM +0200, Michal Hocko wrote: > > > Even for userland tasks, try_to_freeze() can currently be anywhere in > > > the kernel. The frequently used ones are few but there are some odd > > > > I always thought

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-09 Thread Tejun Heo
Hello, On Tue, Sep 09, 2014 at 06:06:25PM +0200, Michal Hocko wrote: > > Even for userland tasks, try_to_freeze() can currently be anywhere in > > the kernel. The frequently used ones are few but there are some odd > > I always thought that user space tasks can be in the fridge only on the >

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-09 Thread Michal Hocko
On Wed 10-09-14 00:23:36, Tejun Heo wrote: > On Tue, Sep 09, 2014 at 05:16:55PM +0200, Michal Hocko wrote: > > But OOM killer doesn't kill kernel threads as they do not own any > > memory. So the check should be safe, no? > > Even for userland tasks, try_to_freeze() can currently be anywhere in >

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-09 Thread Tejun Heo
On Tue, Sep 09, 2014 at 05:16:55PM +0200, Michal Hocko wrote: > But OOM killer doesn't kill kernel threads as they do not own any > memory. So the check should be safe, no? Even for userland tasks, try_to_freeze() can currently be anywhere in the kernel. The frequently used ones are few but

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-09 Thread Michal Hocko
On Tue 09-09-14 07:50:12, Tejun Heo wrote: > Hello, > > On Tue, Sep 09, 2014 at 12:48:28AM +0200, Rafael J. Wysocki wrote: > > Well, not exactly from anywhere. Just from where try_to_freeze() is called > > I suppose? > > Yeap, anywhere try_to_freeze() may be called. > > > Which means that if

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-09 Thread Michal Hocko
On Tue 09-09-14 07:50:12, Tejun Heo wrote: Hello, On Tue, Sep 09, 2014 at 12:48:28AM +0200, Rafael J. Wysocki wrote: Well, not exactly from anywhere. Just from where try_to_freeze() is called I suppose? Yeap, anywhere try_to_freeze() may be called. Which means that if this is a

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-09 Thread Tejun Heo
On Tue, Sep 09, 2014 at 05:16:55PM +0200, Michal Hocko wrote: But OOM killer doesn't kill kernel threads as they do not own any memory. So the check should be safe, no? Even for userland tasks, try_to_freeze() can currently be anywhere in the kernel. The frequently used ones are few but there

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-09 Thread Michal Hocko
On Wed 10-09-14 00:23:36, Tejun Heo wrote: On Tue, Sep 09, 2014 at 05:16:55PM +0200, Michal Hocko wrote: But OOM killer doesn't kill kernel threads as they do not own any memory. So the check should be safe, no? Even for userland tasks, try_to_freeze() can currently be anywhere in the

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-09 Thread Tejun Heo
Hello, On Tue, Sep 09, 2014 at 06:06:25PM +0200, Michal Hocko wrote: Even for userland tasks, try_to_freeze() can currently be anywhere in the kernel. The frequently used ones are few but there are some odd I always thought that user space tasks can be in the fridge only on the way out

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-09 Thread Michal Hocko
On Wed 10-09-14 01:46:58, Tejun Heo wrote: Hello, On Tue, Sep 09, 2014 at 06:06:25PM +0200, Michal Hocko wrote: Even for userland tasks, try_to_freeze() can currently be anywhere in the kernel. The frequently used ones are few but there are some odd I always thought that user space

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-09 Thread Rafael J. Wysocki
On Wednesday, September 10, 2014 12:23:36 AM Tejun Heo wrote: On Tue, Sep 09, 2014 at 05:16:55PM +0200, Michal Hocko wrote: But OOM killer doesn't kill kernel threads as they do not own any memory. So the check should be safe, no? Even for userland tasks, try_to_freeze() can currently be

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-09 Thread Rafael J. Wysocki
On Wednesday, September 10, 2014 01:46:58 AM Tejun Heo wrote: Hello, On Tue, Sep 09, 2014 at 06:06:25PM +0200, Michal Hocko wrote: Even for userland tasks, try_to_freeze() can currently be anywhere in the kernel. The frequently used ones are few but there are some odd I always

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-09 Thread Cong Wang
On Tue, Sep 9, 2014 at 1:48 PM, Rafael J. Wysocki r...@rjwysocki.net wrote: On Wednesday, September 10, 2014 12:23:36 AM Tejun Heo wrote: On Tue, Sep 09, 2014 at 05:16:55PM +0200, Michal Hocko wrote: But OOM killer doesn't kill kernel threads as they do not own any memory. So the check

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-08 Thread Rafael J. Wysocki
On Monday, September 08, 2014 04:29:24 PM Cong Wang wrote: > On Mon, Sep 8, 2014 at 4:42 PM, Rafael J. Wysocki wrote: > > On Monday, September 08, 2014 04:16:15 PM Cong Wang wrote: > >> On Mon, Sep 8, 2014 at 4:23 PM, Rafael J. Wysocki > >> wrote: > >> > > >> > The reason why it matters for the

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-08 Thread Cong Wang
On Mon, Sep 8, 2014 at 4:42 PM, Rafael J. Wysocki wrote: > On Monday, September 08, 2014 04:16:15 PM Cong Wang wrote: >> On Mon, Sep 8, 2014 at 4:23 PM, Rafael J. Wysocki wrote: >> > >> > The reason why it matters for the suspend-time freezing is that we freeze >> > tasks >> > to take them out

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-08 Thread Rafael J. Wysocki
On Monday, September 08, 2014 04:16:15 PM Cong Wang wrote: > On Mon, Sep 8, 2014 at 4:23 PM, Rafael J. Wysocki wrote: > > > > The reason why it matters for the suspend-time freezing is that we freeze > > tasks > > to take them out of the picture entirely until they are thawed. Therefore > > we

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-08 Thread Cong Wang
On Mon, Sep 8, 2014 at 4:23 PM, Rafael J. Wysocki wrote: > > The reason why it matters for the suspend-time freezing is that we freeze > tasks > to take them out of the picture entirely until they are thawed. Therefore we > can't allow them to go back to the picture just for a while until they

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-08 Thread Rafael J. Wysocki
On Monday, September 08, 2014 04:00:41 PM Cong Wang wrote: > On Mon, Sep 8, 2014 at 4:15 PM, Rafael J. Wysocki wrote: > > On Tuesday, September 09, 2014 07:50:12 AM Tejun Heo wrote: > >> Hello, > >> > >> On Tue, Sep 09, 2014 at 12:48:28AM +0200, Rafael J. Wysocki wrote: > >> > Well, not exactly

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-08 Thread Cong Wang
On Mon, Sep 8, 2014 at 4:15 PM, Rafael J. Wysocki wrote: > On Tuesday, September 09, 2014 07:50:12 AM Tejun Heo wrote: >> Hello, >> >> On Tue, Sep 09, 2014 at 12:48:28AM +0200, Rafael J. Wysocki wrote: >> > Well, not exactly from anywhere. Just from where try_to_freeze() is called >> > I

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-08 Thread Rafael J. Wysocki
On Tuesday, September 09, 2014 07:50:12 AM Tejun Heo wrote: > Hello, > > On Tue, Sep 09, 2014 at 12:48:28AM +0200, Rafael J. Wysocki wrote: > > Well, not exactly from anywhere. Just from where try_to_freeze() is called > > I suppose? > > Yeap, anywhere try_to_freeze() may be called. > > >

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-08 Thread Tejun Heo
Hello, On Tue, Sep 09, 2014 at 12:48:28AM +0200, Rafael J. Wysocki wrote: > Well, not exactly from anywhere. Just from where try_to_freeze() is called > I suppose? Yeap, anywhere try_to_freeze() may be called. > Which means that if this is a user space task, it won't to a lot before dying, >

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-08 Thread Rafael J. Wysocki
On Tuesday, September 09, 2014 07:22:53 AM Tejun Heo wrote: > On Mon, Sep 08, 2014 at 11:53:34PM +0200, Rafael J. Wysocki wrote: > > But please tell me this: If TIF_MEMDIE is set and we thaw the process, > > can it do *anything* before dying or will it die immediately? > > The task could be in

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-08 Thread Tejun Heo
On Mon, Sep 08, 2014 at 11:53:34PM +0200, Rafael J. Wysocki wrote: > But please tell me this: If TIF_MEMDIE is set and we thaw the process, > can it do *anything* before dying or will it die immediately? The task could be in freezer from anywhere and there's no limit in what the task may do

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-08 Thread Rafael J. Wysocki
On Monday, September 08, 2014 01:58:30 PM Cong Wang wrote: > On Mon, Sep 8, 2014 at 1:54 PM, Rafael J. Wysocki wrote: > > On Monday, September 08, 2014 10:40:17 AM Cong Wang wrote: > >> > >> We asked you to comment on either if this patch is safe for PM freeze > >> if we don't have the

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-08 Thread Cong Wang
On Mon, Sep 8, 2014 at 1:54 PM, Rafael J. Wysocki wrote: > On Monday, September 08, 2014 10:40:17 AM Cong Wang wrote: >> >> We asked you to comment on either if this patch is safe for PM freeze >> if we don't have the cgroup_freezing() check, or if it is not safe why (so >> that >> I can put it

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-08 Thread Rafael J. Wysocki
On Monday, September 08, 2014 10:40:17 AM Cong Wang wrote: > On Fri, Sep 5, 2014 at 4:32 PM, Rafael J. Wysocki wrote: > > On Saturday, September 06, 2014 07:45:54 AM Tejun Heo wrote: > >> Hello, > >> > >> On Fri, Sep 05, 2014 at 11:12:24AM -0700, Cong Wang wrote: > >> > > Rafael, can you please

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-08 Thread Cong Wang
On Fri, Sep 5, 2014 at 4:32 PM, Rafael J. Wysocki wrote: > On Saturday, September 06, 2014 07:45:54 AM Tejun Heo wrote: >> Hello, >> >> On Fri, Sep 05, 2014 at 11:12:24AM -0700, Cong Wang wrote: >> > > Rafael, can you please help? >> > >> > Rafael is known not responsive at least for this topic.

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-08 Thread Cong Wang
On Fri, Sep 5, 2014 at 4:32 PM, Rafael J. Wysocki r...@rjwysocki.net wrote: On Saturday, September 06, 2014 07:45:54 AM Tejun Heo wrote: Hello, On Fri, Sep 05, 2014 at 11:12:24AM -0700, Cong Wang wrote: Rafael, can you please help? Rafael is known not responsive at least for this topic.

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-08 Thread Rafael J. Wysocki
On Monday, September 08, 2014 10:40:17 AM Cong Wang wrote: On Fri, Sep 5, 2014 at 4:32 PM, Rafael J. Wysocki r...@rjwysocki.net wrote: On Saturday, September 06, 2014 07:45:54 AM Tejun Heo wrote: Hello, On Fri, Sep 05, 2014 at 11:12:24AM -0700, Cong Wang wrote: Rafael, can you please

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-08 Thread Cong Wang
On Mon, Sep 8, 2014 at 1:54 PM, Rafael J. Wysocki r...@rjwysocki.net wrote: On Monday, September 08, 2014 10:40:17 AM Cong Wang wrote: We asked you to comment on either if this patch is safe for PM freeze if we don't have the cgroup_freezing() check, or if it is not safe why (so that I can

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-08 Thread Rafael J. Wysocki
On Monday, September 08, 2014 01:58:30 PM Cong Wang wrote: On Mon, Sep 8, 2014 at 1:54 PM, Rafael J. Wysocki r...@rjwysocki.net wrote: On Monday, September 08, 2014 10:40:17 AM Cong Wang wrote: We asked you to comment on either if this patch is safe for PM freeze if we don't have the

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-08 Thread Tejun Heo
On Mon, Sep 08, 2014 at 11:53:34PM +0200, Rafael J. Wysocki wrote: But please tell me this: If TIF_MEMDIE is set and we thaw the process, can it do *anything* before dying or will it die immediately? The task could be in freezer from anywhere and there's no limit in what the task may do before

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-08 Thread Rafael J. Wysocki
On Tuesday, September 09, 2014 07:22:53 AM Tejun Heo wrote: On Mon, Sep 08, 2014 at 11:53:34PM +0200, Rafael J. Wysocki wrote: But please tell me this: If TIF_MEMDIE is set and we thaw the process, can it do *anything* before dying or will it die immediately? The task could be in freezer

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-08 Thread Tejun Heo
Hello, On Tue, Sep 09, 2014 at 12:48:28AM +0200, Rafael J. Wysocki wrote: Well, not exactly from anywhere. Just from where try_to_freeze() is called I suppose? Yeap, anywhere try_to_freeze() may be called. Which means that if this is a user space task, it won't to a lot before dying, will

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-08 Thread Rafael J. Wysocki
On Tuesday, September 09, 2014 07:50:12 AM Tejun Heo wrote: Hello, On Tue, Sep 09, 2014 at 12:48:28AM +0200, Rafael J. Wysocki wrote: Well, not exactly from anywhere. Just from where try_to_freeze() is called I suppose? Yeap, anywhere try_to_freeze() may be called. Which means that

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-08 Thread Cong Wang
On Mon, Sep 8, 2014 at 4:15 PM, Rafael J. Wysocki r...@rjwysocki.net wrote: On Tuesday, September 09, 2014 07:50:12 AM Tejun Heo wrote: Hello, On Tue, Sep 09, 2014 at 12:48:28AM +0200, Rafael J. Wysocki wrote: Well, not exactly from anywhere. Just from where try_to_freeze() is called I

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-08 Thread Rafael J. Wysocki
On Monday, September 08, 2014 04:00:41 PM Cong Wang wrote: On Mon, Sep 8, 2014 at 4:15 PM, Rafael J. Wysocki r...@rjwysocki.net wrote: On Tuesday, September 09, 2014 07:50:12 AM Tejun Heo wrote: Hello, On Tue, Sep 09, 2014 at 12:48:28AM +0200, Rafael J. Wysocki wrote: Well, not exactly

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-08 Thread Cong Wang
On Mon, Sep 8, 2014 at 4:23 PM, Rafael J. Wysocki r...@rjwysocki.net wrote: The reason why it matters for the suspend-time freezing is that we freeze tasks to take them out of the picture entirely until they are thawed. Therefore we can't allow them to go back to the picture just for a

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-08 Thread Rafael J. Wysocki
On Monday, September 08, 2014 04:16:15 PM Cong Wang wrote: On Mon, Sep 8, 2014 at 4:23 PM, Rafael J. Wysocki r...@rjwysocki.net wrote: The reason why it matters for the suspend-time freezing is that we freeze tasks to take them out of the picture entirely until they are thawed.

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-08 Thread Cong Wang
On Mon, Sep 8, 2014 at 4:42 PM, Rafael J. Wysocki r...@rjwysocki.net wrote: On Monday, September 08, 2014 04:16:15 PM Cong Wang wrote: On Mon, Sep 8, 2014 at 4:23 PM, Rafael J. Wysocki r...@rjwysocki.net wrote: The reason why it matters for the suspend-time freezing is that we freeze

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-08 Thread Rafael J. Wysocki
On Monday, September 08, 2014 04:29:24 PM Cong Wang wrote: On Mon, Sep 8, 2014 at 4:42 PM, Rafael J. Wysocki r...@rjwysocki.net wrote: On Monday, September 08, 2014 04:16:15 PM Cong Wang wrote: On Mon, Sep 8, 2014 at 4:23 PM, Rafael J. Wysocki r...@rjwysocki.net wrote: The reason why

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-05 Thread Rafael J. Wysocki
On Saturday, September 06, 2014 07:45:54 AM Tejun Heo wrote: > Hello, > > On Fri, Sep 05, 2014 at 11:12:24AM -0700, Cong Wang wrote: > > > Rafael, can you please help? > > > > Rafael is known not responsive at least for this topic. :) > > :( Well, am I? I haven't commented patches in this

Re: [Patch v4 1/2] freezer: check OOM kill while being frozen

2014-09-05 Thread Tejun Heo
Hello, On Fri, Sep 05, 2014 at 11:12:24AM -0700, Cong Wang wrote: > > Rafael, can you please help? > > Rafael is known not responsive at least for this topic. :) :( > > Shouldn't the primary goal of the comment be explaining why we need > > TIF_MEMDIE check there at all anyway? The deadlock

  1   2   >