Messages in this thread | | | Date | Mon, 27 Dec 2004 18:42:15 +0100 | From | Manfred Spraul <> | Subject | Re: PATCH: kmalloc packet slab |
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> > >Why 1620 bytes ? > Because then 5 objects will fit into one 8 kB memory block: 5*1620+slab control structure.
> Most drivers allocate packet_size + 2 bytes. >dev_alloc_skb adds another 16 bytes, finally alloc_skb adds >sizeof(struct skb_shared_info). > > > >(32bit): 1514b + 2b + 16b + 160b = 1692b >(64bit): 1514b + 2b + 16b + 312b = 1844b > > > Hmm. If the shared_info is that large then the patch won't help much.
Alan - what is printed in the /proc/slabinfo line for the new cache? - 1620 bytes is probably a bit too much for archs with 128 byte cache lines and 8 kB pages. If I've calculated correctly, only 4 will fit into one page. - if the shared info is really that large - is the patch actually useful?
-- Manfred
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