On Tue, Apr 10, 2012 at 3:00 PM, Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > On Mon, 9 Apr 2012 14:59:00 -0500 > Will Drewry <wad@xxxxxxxxxxxx> wrote: > >> >> I think this gives userspace an easy way of causing page allocation >> >> failure warnings, by permitting large kmalloc() attempts. __Add >> >> __GFP_NOWARN? >> > >> > Max is 32kb. sk_attach_filter() in net/core/filter.c is worse, >> > it allocates up to 512kb before even checking the length. >> > >> > What about using GFP_USER (and adding __GFP_NOWARN to GFP_USER) instead? >> >> It looks like GFP_USER|__GFP_NOWARN would make sense here. I'll change it. > > I'm not really sure why GFP_USER exists. It's very rarely used, and > most usages are probably inappropriate. To me it means "same as > GFP_HIGHUSER, only don't use highmem". That's relevant to blockdev > pagecache and nothing else as far as I can tell. And good luck working > out what the __GFP_HARDWALL does ;) I was wildly speculating about it, but maybe I should stop doing that. > This is a regular old allocation of kernel memory - the thing to use > here is GFP_KERNEL|__GFP_NOWARN. Sounds good - I've just changed the patchset to that effect. > (I'm surprised that we didn't remove __GFP_NOWARN ages ago - warning by > default is pretty obnoxious. But the warning continues to be > occasionally useful and false positives are rare). > -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
