aboutsummaryrefslogtreecommitdiff
path: root/include/asm-x86_64/tlbflush.h
AgeCommit message (Collapse)Author
2005-09-12[PATCH] x86-64: Increase TLB flush array sizeAndi Kleen
The generic TLB flush functions kept upto 506 pages per CPU to avoid too frequent IPIs. This value was done for the L1 cache of older x86 CPUs, but with modern CPUs it does not make much sense anymore. TLB flushing is slow enough that using the L2 cache is fine. This patch increases the flush array on x86-64 to cache 5350 pages. That is roughly 20MB with 4K pages. It speeds up large munmaps in multithreaded processes on SMP considerably. The cost is roughly 42k of memory per CPU, which is reasonable. I only increased it on x86-64 for now, but it would probably make sense to increase it everywhere. Embedded architectures with SMP may keep it smaller to save some memory per CPU. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-28[PATCH] x86_64: Fix some comments in tlbflush.hAndi Kleen
Were either outdated or misleading. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-27[PATCH] seccomp: tsc disableAndrea Arcangeli
I believe at least for seccomp it's worth to turn off the tsc, not just for HT but for the L2 cache too. So it's up to you, either you turn it off completely (which isn't very nice IMHO) or I recommend to apply this below patch. This has been tested successfully on x86-64 against current cogito repository (i686 compiles so I didn't bother testing ;). People selling the cpu through cpushare may appreciate this bit for a peace of mind. There's no way to get any timing info anymore with this applied (gettimeofday is forbidden of course). The seccomp environment is completely deterministic so it can't be allowed to get timing info, it has to be deterministic so in the future I can enable a computing mode that does a parallel computing for each task with server side transparent checkpointing and verification that the output is the same from all the 2/3 seller computers for each task, without the buyer even noticing (for now the verification is left to the buyer client side and there's no checkpointing, since that would require more kernel changes to track the dirty bits but it'll be easy to extend once the basic mode is finished). Eliminating a cold-cache read of the cr4 global variable will save one cacheline during the tlb flush while making the code per-cpu-safe at the same time. Thanks to Mikael Pettersson for noticing the tlb flush wasn't per-cpu-safe. The global tlb flush can run from irq (IPI calling do_flush_tlb_all) but it'll be transparent to the switch_to code since the IPI won't make any change to the cr4 contents from the point of view of the interrupted code and since it's now all per-cpu stuff, it will not race. So no need to disable irqs in switch_to slow path. Signed-off-by: Andrea Arcangeli <andrea@cpushare.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-16Linux-2.6.12-rc2Linus Torvalds
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!