Re: [PATCH] mm-slab: allocate kmem_cache with __GFP_REPEAT
From: Pekka Enberg <penberg@kernel.org>
Date: 2011-07-20 13:42:41
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On Wed, 20 Jul 2011, Konstantin Khlebnikov wrote:
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The changelog isn't that convincing, really. This is kmem_cache_create() so I'm surprised we'd ever get NULL here in practice. Does this fix some problem you're seeing? If this is really an issue, I'd blame the page allocator as GFP_KERNEL should just work.nf_conntrack creates separate slab-cache for each net-namespace, this patch of course not eliminates the chance of failure, but makes it more acceptable.
I'm still surprised you are seeing failures. mm/slab.c hasn't changed significantly in a long time. Why hasn't anyone reported this before? I'd still be inclined to shift the blame to the page allocator... Mel, Christoph? On Wed, 20 Jul 2011, Konstantin Khlebnikov wrote:
struct kmem_size for slub is more compact, it uses pecpu-pointers instead of dumb NR_CPUS-size array. probably better to fix this side...
So how big is 'struct kmem_cache' for your configuration anyway? Fixing the per-cpu data structures would be nice but I'm guessing it'll be slightly painful for mm/slab.c. Pekka -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>