Messages in this thread | | | Date | Thu, 7 May 2009 13:02:02 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH 1/5] mm: Add __GFP_NO_OOM_KILL flag |
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On Thu, 7 May 2009 21:33:47 +0200 "Rafael J. Wysocki" <rjw@sisk.pl> wrote:
> On Thursday 07 May 2009, Andrew Morton wrote: > > On Thu, 7 May 2009 20:09:52 +0200 > > "Rafael J. Wysocki" <rjw@sisk.pl> wrote: > > > > > > > > I'm suspecting that hibernation can allocate its pages with > > > > > > __GFP_FS|__GFP_WAIT|__GFP_NORETRY|__GFP_NOWARN, and the page allocator > > > > > > will dtrt: no oom-killings. > > > > > > > > > > > > In which case, processes_are_frozen() is not needed at all? > > > > > > > > > > __GFP_NORETRY alone causes it to fail relatively quickly, but I'll try with > > > > > the combination. > > > > > > > > OK. __GFP_WAIT is the big hammer. > > > > > > Unfortunately it fails too quickly with the combination as well, so it looks > > > like we can't use __GFP_NORETRY during hibernation. > > > > hm. > > > > So where do we stand now? > > > > I'm not a big fan of the global application-specific state change > > thing. Something like __GFP_NO_OOM_KILL has a better chance of being > > reused by other subsystems in the future, which is a good indicator. > > I'm not against __GFP_NO_OOM_KILL, but there's been some strong resistance to > adding new _GPF _FOO flags recently.
We have six or seven left - hardly a crisis.
> Is there any likelihood anyone else we'll > really need it any time soon?
Dunno - people do all sorts of crazy things. But it's more likely to be reused than a PM-specific global!
I have no strong feelings really, but slotting into the existing technique with something which might be reusable is quite a bit tidier.
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