Messages in this thread | | | Subject | Re: [PATCH] Do not pass the SLAB flags as GFP in slob kmem_cache_create | From | Matt Mackall <> | Date | Wed, 10 Dec 2008 13:57:50 -0600 |
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On Wed, 2008-12-10 at 22:34 +0300, Cyrill Gorcunov wrote: > [Catalin Marinas - Wed, Dec 10, 2008 at 05:36:33PM +0000] > | It looks like the kmem_cache_create() function in the slob allocator > | passes the SLAB flags as GFP flags to the slob_alloc() function. The > | patch changes this call to pass GFP_KERNEL as the other allocators seem > | to do. > | > | Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> > | Cc: Matt Mackall <mpm@selenic.com> > | --- > | mm/slob.c | 2 +- > | 1 files changed, 1 insertions(+), 1 deletions(-) > | > | diff --git a/mm/slob.c b/mm/slob.c > | index ff5a98d..dce9258 100644 > | --- a/mm/slob.c > | +++ b/mm/slob.c > | @@ -538,7 +538,7 @@ struct kmem_cache *kmem_cache_create(const char *name, size_t size, > | struct kmem_cache *c; > | > | c = slob_alloc(sizeof(struct kmem_cache), > | - flags, ARCH_KMALLOC_MINALIGN, -1); > | + GFP_KERNEL, ARCH_KMALLOC_MINALIGN, -1); > | > | if (c) { > | c->name = name; > | > > Hi Catalin, > > this would make the following line in slob_alloc > > ... > if (unlikely((gfp & __GFP_ZERO) && b)) > memset(b, 0, size); > ... > > useless. Not sure if it will be good :)
I think that's fine. Notice that this is not the allocation of an object, but the allocation of a cache descriptor. We save the flags inside the descriptor so that when the user calls kmem_cache_alloc, we can pass them along to slob_alloc, where GFP_ZERO can take effect.
So, if we're comfortable with the idea that we can only create caches in 'normal' contexts, then I think the patch is fine.
-- Mathematics is the supreme nostalgia of our time.
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