Messages in this thread | | | Subject | Re: iozone regression with 2.6.29-rc6 | From | Lin Ming <> | Date | Mon, 02 Mar 2009 11:16:41 +0800 |
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On Mon, 2009-03-02 at 11:12 +0800, Wu, Fengguang wrote: > On Mon, Mar 02, 2009 at 10:19:04AM +0800, Lin, Ming wrote: > > On Fri, 2009-02-27 at 17:49 +0800, Peter Zijlstra wrote: > > > On Fri, 2009-02-27 at 17:13 +0800, Lin Ming wrote: > > > > bisect locates below commits, > > > > > > > > commit 1cf6e7d83bf334cc5916137862c920a97aabc018 > > > > Author: Nick Piggin <npiggin@suse.de> > > > > Date: Wed Feb 18 14:48:18 2009 -0800 > > > > > > > > mm: task dirty accounting fix > > > > > > > > YAMAMOTO-san noticed that task_dirty_inc doesn't seem to be called properly for > > > > cases where set_page_dirty is not used to dirty a page (eg. mark_buffer_dirty). > > > > > > > > Additionally, there is some inconsistency about when task_dirty_inc is > > > > called. It is used for dirty balancing, however it even gets called for > > > > __set_page_dirty_no_writeback. > > > > > > > > So rather than increment it in a set_page_dirty wrapper, move it down to > > > > exactly where the dirty page accounting stats are incremented. > > > > > > > > Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp> > > > > Signed-off-by: Nick Piggin <npiggin@suse.de> > > > > Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> > > > > Signed-off-by: Andrew Morton <akpm@linux-foundation.org> > > > > Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> > > > > > > > > > > > > below data in parenthesis is the result after above commit reverted, for example, > > > > -10% (+2%) means, > > > > iozone has ~10% regression with 2.6.29-rc6 compared with 2.6.29-rc5. > > > > and > > > > iozone has ~2% improvement with 2.6.29-rc6-revert-1cf6e7d compared with 2.6.29-rc5. > > > > > > > > > > > > 4P dual-core HT 2P qual-core 2P qual-core HT > > > > tulsa stockley Nehalem > > > > -------------------------------------------------------- > > > > iozone-rewrite -10% (+2%) -8% (0%) -10% (-7%) > > > > iozone-rand-write -50% (0%) -20% (+10%) > > > > iozone-read -13% (0%) > > > > iozone-write -28% (-1%) > > > > iozone-reread -5% (-1%) > > > > iozone-mmap-read -7% (+2%) > > > > iozone-mmap-reread -7% (+2%) > > > > iozone-mmap-rand-read -7% (+3%) > > > > iozone-mmap-rand-write -5% (0%) > > > > > > Ugh, that's unexpected.. > > > > > > So 'better' accounting leads to worse performance, which would indicate > > > we throttle more. > > > > > > I take it you machine has gobs of memory. > > > > > > Does something like the below help any? > > > > It helps some as below test result, > > The data in second parenthesis means 2.6.29-rc6-with-peter's-patch > > compared with 2.6.29-rc5. > > > > 4P dual-core HT 2P qual-core 2P qual-core HT > > tulsa stockley Nehalem > > -------------------------------------------------------- > > iozone-rewrite -10% (+2%)(-3%) -8% (0%)(0%) -10% (-7%)(-2%) > > iozone-rand-write -50% (0%)(-10%) -20% (+10%)(+3%) > > iozone-read -13% (0%)(-8%) > > iozone-write -28% (-1%)(+35%) > > iozone-reread -5% (-1%)(-1%) > > iozone-mmap-read -7% (+2%)(-7%) > > iozone-mmap-reread -7% (+2%)(-7%) > > iozone-mmap-rand-read -7% (+3%)(-7%) > > iozone-mmap-rand-write -5% (0%)(+27%) > > Thanks, Lin Ming. To better understand the situation, would you please > provide the iozone command and memory info about the servers?
iozone -i 0 -i 1 -i 2 -i 3 -i 4 -r 4k -s 64k -s 512m -s 1200m -b tmp.xls iozone -B -r 4k -s 64k -s 512m -s 1200m -b tmp.xls
4P dual-core HT tulsa /proc/meminfo ------------------------------------ MemTotal: 8189476 kB MemFree: 7915884 kB Buffers: 32676 kB Cached: 139784 kB SwapCached: 0 kB Active: 35852 kB Inactive: 145564 kB Active(anon): 9048 kB Inactive(anon): 0 kB Active(file): 26804 kB Inactive(file): 145564 kB Unevictable: 0 kB Mlocked: 0 kB SwapTotal: 0 kB SwapFree: 0 kB Dirty: 140 kB Writeback: 0 kB AnonPages: 9068 kB Mapped: 4084 kB Slab: 31180 kB SReclaimable: 14800 kB SUnreclaim: 16380 kB PageTables: 1236 kB NFS_Unstable: 0 kB Bounce: 0 kB WritebackTmp: 0 kB CommitLimit: 4094736 kB Committed_AS: 18446744073709545248 kB VmallocTotal: 34359738367 kB VmallocUsed: 286416 kB VmallocChunk: 34359449467 kB HugePages_Total: 0 HugePages_Free: 0 HugePages_Rsvd: 0 HugePages_Surp: 0 Hugepagesize: 2048 kB DirectMap4k: 4096 kB DirectMap2M: 8380416
2P qual-core stockley /proc/meminfo ----------------------------------- MemTotal: 8167260 kB MemFree: 7951068 kB Buffers: 30988 kB Cached: 123772 kB SwapCached: 0 kB Active: 34744 kB Inactive: 129296 kB Active(anon): 9412 kB Inactive(anon): 0 kB Active(file): 25332 kB Inactive(file): 129296 kB Unevictable: 0 kB Mlocked: 0 kB SwapTotal: 0 kB SwapFree: 0 kB Dirty: 272 kB Writeback: 0 kB AnonPages: 9408 kB Mapped: 4072 kB Slab: 21760 kB SReclaimable: 10612 kB SUnreclaim: 11148 kB PageTables: 1260 kB NFS_Unstable: 0 kB Bounce: 0 kB WritebackTmp: 0 kB CommitLimit: 4083628 kB Committed_AS: 18446744073709540996 kB VmallocTotal: 34359738367 kB VmallocUsed: 11216 kB VmallocChunk: 34359726459 kB HugePages_Total: 0 HugePages_Free: 0 HugePages_Rsvd: 0 HugePages_Surp: 0 Hugepagesize: 2048 kB DirectMap4k: 7168 kB DirectMap2M: 8380416 kB
2P qual-core HT Nehalem /proc/meminfo ------------------------------------- MemTotal: 6113044 kB MemFree: 5947476 kB Buffers: 17056 kB Cached: 44280 kB SwapCached: 0 kB Active: 31268 kB Inactive: 40300 kB Active(anon): 10308 kB Inactive(anon): 0 kB Active(file): 20960 kB Inactive(file): 40300 kB Unevictable: 0 kB Mlocked: 0 kB SwapTotal: 0 kB SwapFree: 0 kB Dirty: 280 kB Writeback: 0 kB AnonPages: 10328 kB Mapped: 5096 kB Slab: 27844 kB SReclaimable: 10988 kB SUnreclaim: 16856 kB PageTables: 2204 kB NFS_Unstable: 0 kB Bounce: 0 kB WritebackTmp: 0 kB CommitLimit: 3056520 kB Committed_AS: 18446744073709542732 kB VmallocTotal: 34359738367 kB VmallocUsed: 286428 kB VmallocChunk: 34359451259 kB HugePages_Total: 0 HugePages_Free: 0 HugePages_Rsvd: 0 HugePages_Surp: 0 Hugepagesize: 2048 kB DirectMap4k: 8192 kB DirectMap2M: 6275072 kB
Lin Ming
> > Thanks, > Fengguang
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