Messages in this thread | | | From | Oliver Neukum <> | Subject | Re: [2.6 patch] i386: always use 4k stacks | Date | Fri, 16 Dec 2005 20:14:35 +0100 |
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Am Freitag, 16. Dezember 2005 20:02 schrieb Arjan van de Ven: > > > > > So what about arches where single-page stacks aren't viable (for example > > x86_64)? Are we just screwed? > > > x86 is specially handicapped due to the fact that the stacks need to be > in the lowmem zone. Even if you have 8Gb ram, the lowmem zone is still > 800Mb and a bit, and this gets to be under a high pressure, like > hyper-fragmentation. Same for bounce buffers etc etc. > > note that the order thing is by far not the only advantage, pure memory > usage alone and cache locality also are wins. The memory usage halves > for kernel stacks after all (which means you can do more threads in > java, or use the memory for disk cache ;)
1. Cache usage depends on actual stack usage. How much you allocate doesn't matter 2. You are surely getting a cache effect by using interrupt stacks. Which is larger? 3. When you use kmalloc instead of the stack you are reducing locality.
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