Messages in this thread | | | Date | Sun, 15 Jun 2003 03:23:32 -0700 | From | William Lee Irwin III <> | Subject | 2.5.71-wli-1 |
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I pounded out a few patches to make my boxen run a little smoother. This runs great on my big fat PAE boxen and on my craptop. It may very well prove useful to others as well.
This will compile for i386 only, though I'm interested in merging the fixes so other arches compile and so on.
To preemptively answer the question, I suspect a couple of these are more than -mm cares to absorb at the moment. Of course, if that turns out not to be the case, I'll send things in promptly.
Against virgin 2.5.71.
Available from: ftp://ftp.kernel.org/pub/linux/kernel/people/wli/kernels/2.5.71/linux-2.5.71-wli-1.bz2
1: O(1) rmqueue_bulk() rmqueue_bulk() currently does list walking and various kinds of iteration every time in what's obviously a fast path. This batches up prepped groups of pages in internal buddy allocator lists so rmqueue_bulk() has O(1) expected time. free_pages_bulk() is likewise trimmed down from O(group) to O(1) expected time.
2: trivial flow.c compilefix The same thing everyone else has posted a dozen times.
3: lowmem_page_address() micro-optimization Use page_to_pfn() instead of open-coding page_zone() etc. so micro-optimized arch implementations of page_to_pfn() can micro-optimize lowmem_page_address() in turn.
4: highpmd Shove i386 pmd's into highmem, brute-force. make -j bzImage now incurs near-negligible lowmem pressure on my NUMA-Q. A very comfortable feeling indeed. This was really a very mechanical job, and it fits very smoothly into the core. This is the patch that breaks non-i386 arches' compiles, though it's obvious how to fix it, i.e. pmd_offset_map() etc. and pgd_page() changes.
5: trivial /proc/ BKL removals Relatively unimportant, apart from the fact the BKL is annoying and obscuring what's being locked in and around /proc/ due to the BKL's inherent "wtf did they just lock" nature. There isn't anything significant to audit around the specific codepaths invoved, as one wrapped a call to a function that wrapped its entire body in the BKL and the other wrapped a variable (nr_threads) actually protected by the tasklist_lock, but considered valid to access with no locking for reporting.
6: i386 pagetable cache Use the tlb.h hooks to properly cache pre-zeroed pagetable and pmd pages as well as to function properly with highpte/highpmd. Slick implementation techniques make this O(1) in all cases, with no list iterations, and no nonsense in general. One might say this removes some nonsense, as they're trivially cacheable.
7: pgd_ctor() Use slab ctors to cache preconstructed pgd's. This is worth more on non-PAE machines, as significant amounts of bitblitting are incurred when the things are a whole page in size. A form of this is already in -mm, but this version works with highpmd.
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