Messages in this thread |  | | | From | Mike Waychison <> | | Date | Tue, 10 Jan 2012 17:42:24 -0800 | | Subject | Re: [PATCH v2 1/3] virtio_net: Split receive buffer alloc/add |
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On Tue, Jan 10, 2012 at 5:30 PM, Rusty Russell <rusty@rustcorp.com.au> wrote: > On Tue, 10 Jan 2012 09:41:01 -0800, Mike Waychison <mikew@google.com> wrote: >> In preparation for allocating receive buffers in the slow path without >> disabling NAPI, split the allocation and addition of receive buffers >> apart into two separate functions (per receive buffer type). >> >> While here, move the vi->num accounting into the add functions. >> >> Signed-off-by: Mike Waychison <mikew@google.com> > > Hi Mike... > > This exposes a nasty ugliness in the way virtio_net works. We > allocate an skbuff for the small packet case, and just allocate the > pages for the large packet cases, and alloc the skbuff when we fill the > pages. > > I think all the allocators should return a populated skbuff; > this uses a bit more memory in theory, but should make the code simpler. > As an added bonus, your life should get much simpler for these patches. > > I'll try to create such a patch tonight, but I'm busy finalizing my > linux.conf.au presentation, so it might take longer :( >
This seems reasonable for the "big" receive buffers, but I don't think it makes a lot of sense for "mergeable" receive buffers as best I can tell. Hopefully making this work isn't too hard though :) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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