Messages in this thread | | | Date | Tue, 17 Nov 2009 00:36:38 -0800 (PST) | From | David Rientjes <> | Subject | Re: [PATCH 0/7] Kill PF_MEMALLOC abuse |
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On Tue, 17 Nov 2009, KOSAKI Motohiro wrote:
> > I agree in principle with removing non-VM users of PF_MEMALLOC, but I > > think it should be left to the individual subsystem maintainers to apply > > or ack since the allocations may depend on the __GFP_NORETRY | ~__GFP_WAIT > > behavior of PF_MEMALLOC. This could be potentially dangerous for a > > PF_MEMALLOC user if allocations made by the kthread, for example, should > > never retry for orders smaller than PAGE_ALLOC_COSTLY_ORDER or block on > > direct reclaim. > > if there is so such reason. we might need to implement another MM trick. > but keeping this strage usage is not a option. All memory freeing activity > (e.g. page out, task killing) need some memory. we need to protect its > emergency memory. otherwise linux reliability decrease dramatically when > the system face to memory stress. >
Right, that's why I agree with trying to remove non-VM use of PF_MEMALLOC, but I think this patchset needs to go through the individual subsystem maintainers so they can ensure the conversion doesn't cause undesirable results if their kthreads' memory allocations depend on the __GFP_NORETRY behavior that PF_MEMALLOC ensures. Otherwise it looks good.
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