Messages in this thread | | | Date | Sun, 18 Mar 2007 09:59:39 -0500 | From | Bill Davidsen <> | Subject | Re: [PATCH 0/3] VM throttling: avoid blocking occasional writers |
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Andrew Morton wrote: >> On Wed, 14 Mar 2007 21:42:46 +0900 Tomoki Sekiyama <tomoki.sekiyama.qu@hitachi.com> wrote: >> >> ... >> >> >> -Solution: >> >> I consider that all of the dirty pages for the disk have been written >> back and that the disk is clean if a process cannot write 'write_chunk' >> pages in balance_dirty_pages(). >> >> To avoid using up the free memory with dirty pages by passing blocking, >> this patchset adds a new threshold named vm.dirty_limit_ratio to sysctl. >> >> It modifies balance_dirty_pages() not to block when the amount of >> Dirty+Writeback is less than vm.dirty_limit_ratio percent of the memory. >> In the other cases, writers are throttled as current Linux does. >> >> >> In this patchset, vm.dirty_limit_ratio, instead of vm.dirty_ratio, is >> used as the clamping level of Dirty+Writeback. And, vm.dirty_ratio is >> used as the level at which a writers will itself start writeback of the >> dirty pages. > > Might be a reasonable solution - let's see what Peter comes up with too. > > Comments on the patch: > > - Please don't VM_DIRTY_LIMIT_RATIO: just use CTL_UNNUMBERED and leave > sysctl.h alone. > > - The 40% default is already too high. Let's set this new upper limit to > 40% and decrease he non-blocking ratio. > > - Please update the procfs documentation in ./Docmentation/ > > - I wonder if dirty_limit_ratio is the best name we could choose. > vm_dirty_blocking_ratio, perhaps? Dunno. > I don't like it, but I dislike it less than "dirty_limit_ratio" I guess. It would probably break things to change it now, including my sysctl.conf on a number of systems :-(
-- Bill Davidsen <davidsen@tmr.com> "We have more to fear from the bungling of the incompetent than from the machinations of the wicked." - from Slashdot - 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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