Messages in this thread | | | Date | Wed, 25 Dec 2013 11:56:15 +0800 | From | Fengguang Wu <> | Subject | Re: [sched] perf-stat.cpu-migrations changes in dd write test |
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On Wed, Dec 25, 2013 at 11:30:27AM +0800, Alex Shi wrote: > On 12/23/2013 01:24 PM, Fengguang Wu wrote: > > On Mon, Dec 23, 2013 at 01:19:04PM +0800, Alex Shi wrote: > >> On 12/22/2013 08:30 AM, fengguang.wu@intel.com wrote: > >>> Alex, > >>> > >>> We noticed some perf-stat.cpu-migrations changes by your commit > >> > >> Thanks for your wonder testing, Fengguang! > >> How many CPU in your system and how many dd task running? > > > > For the case > > > > kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd > > > > It's a KVM with 4 CPUs, 16G memory. There are 4 virtual disks, on top > > of each disk there runs 10 dd tasks. > > I don't know much of kvm. Where the data get from, VM guest or VM host?
The data are collected in the VM guest.
Thanks, Fengguang
> Looks like any guest cpu usage will be counted as user usage in vmstat. > and Does the CS and cpu migration reducing cause dd performance increase? > > > > Thanks, > > Fengguang > > > >>> > >>> 6eb8b571283e64e96ca1a91aad085f9e08f857f0 is the first bad commit > >>> commit 6eb8b571283e64e96ca1a91aad085f9e08f857f0 > >>> Author: Alex Shi <alex.shi@linaro.org> > >>> Date: Tue Nov 19 20:29:51 2013 +0800 > >>> > >>> sched: remove rq->cpu_load[load_idx] array > >>> > >>> Since load_idx effect removed in load balance, we don't need the > >>> load_idx decays in scheduler. that will save some process in sched_tick > >>> and others places. > >>> > >>> Signed-off-by: Alex Shi <alex.shi@linaro.org> > >>> > >>> > >>> Here are the changed stats comparing to its parent commit: > >>> > >>> 1de157d718f6494 6eb8b571283e64e96ca1 > >>> --------------- ------------------------- > >>> 37779 ~40% +115.2% 81288 ~50% kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd > >>> 37779 +115.2% 81288 TOTAL proc-vmstat.pgscan_direct_normal > >>> > >>> kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd: proc-vmstat.pgscan_direct_normal > >>> > >>> 160000 ++----------------------------------------------------------------+ > >>> | | > >>> 140000 ++ O > >>> | | > >>> 120000 ++ | > >>> | O | > >>> 100000 ++ | > >>> | | > >>> 80000 ++ O | > >>> | ..* > >>> 60000 ++ .... | > >>> | .... | > >>> 40000 *+............... O .... | > >>> O *............... ........*. | > >>> 20000 ++-------------------------------*--------------------------------+ > >>> > >>> > >>> 1de157d718f6494 6eb8b571283e64e96ca1 > >>> --------------- ------------------------- > >>> 121579 ~ 6% -50.8% 59852 ~13% kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd > >>> 121579 -50.8% 59852 TOTAL softirqs.SCHED > >>> > >>> kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd: softirqs.SCHED > >>> > >>> 140000 ++----------------------------------------------------------------+ > >>> 130000 ++ ....*........... ....*....... | > >>> | ........ .... ........ ...... | > >>> 120000 *+... *.... ..| > >>> 110000 ++ * > >>> | | > >>> 100000 ++ | > >>> 90000 ++ | > >>> 80000 ++ | > >>> | | > >>> 70000 ++ O O | > >>> 60000 ++ O | > >>> | O > >>> 50000 O+ | > >>> 40000 ++----------------------------------------------------------------+ > >>> > >>> > >>> 1de157d718f6494 6eb8b571283e64e96ca1 > >>> --------------- ------------------------- > >>> 5636 ~ 4% -22.1% 4392 ~17% kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd > >>> 5636 -22.1% 4392 TOTAL proc-vmstat.nr_tlb_remote_flush > >>> > >>> kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd: proc-vmstat.nr_tlb_remote_flush > >>> > >>> 6500 ++------------------------------------------------------------------+ > >>> | | > >>> 6000 ++ ........*............ | > >>> *........ .... | > >>> 5500 ++ O *................*................| > >>> | * > >>> 5000 ++ O | > >>> | | > >>> 4500 ++ O | > >>> | | > >>> 4000 ++ | > >>> | O > >>> 3500 O+ | > >>> | | > >>> 3000 ++------------------------------------------------------------------+ > >>> > >>> > >>> 1de157d718f6494 6eb8b571283e64e96ca1 > >>> --------------- ------------------------- > >>> 5679 ~ 4% -21.9% 4437 ~17% kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd > >>> 5679 -21.9% 4437 TOTAL proc-vmstat.nr_tlb_remote_flush_received > >>> > >>> > >>> > >>> 6500 ++------------------------------------------------------------------+ > >>> | | > >>> 6000 ++ ........*........ | > >>> *........ ...... | > >>> | .. ........*................| > >>> 5500 ++ O *........ * > >>> | | > >>> 5000 ++ O | > >>> | | > >>> 4500 ++ O | > >>> | | > >>> | | > >>> 4000 ++ | > >>> | O > >>> 3500 O+------------------------------------------------------------------+ > >>> > >>> > >>> 1de157d718f6494 6eb8b571283e64e96ca1 > >>> --------------- ------------------------- > >>> 167 ~11% +19.4% 200 ~ 4% kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd > >>> 167 +19.4% 200 TOTAL uptime.idle > >>> > >>> kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd: uptime.idle > >>> > >>> 220 ++-------------------------------------------------------------------+ > >>> | O > >>> 210 ++ | > >>> 200 O+ O | > >>> | ..*..... O | > >>> 190 ++ .... O ... | > >>> 180 ++ .... .... | > >>> | .... .... | > >>> 170 *+. . .* > >>> 160 ++ *...... .... | > >>> | .... ... | > >>> 150 ++ .... ... | > >>> 140 ++ .. .... | > >>> | *. | > >>> 130 ++-------------------------------------------------------------------+ > >>> > >>> > >>> 1de157d718f6494 6eb8b571283e64e96ca1 > >>> --------------- ------------------------- > >>> 154781 ~ 5% -66.8% 51449 ~ 8% kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd > >>> 154781 -66.8% 51449 TOTAL perf-stat.cpu-migrations > >>> > >>> kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd: perf-stat.cpu-migrations > >>> > >>> 180000 ++----------------------------------------------------------------+ > >>> | ....*........... | > >>> 160000 ++ ........ .... ........*...............| > >>> *.... *........ * > >>> 140000 ++ | > >>> | | > >>> 120000 ++ | > >>> | | > >>> 100000 ++ | > >>> | | > >>> 80000 ++ | > >>> | | > >>> 60000 ++ O | > >>> | O O O > >>> 40000 O+----------------------------------------------------------------+ > >>> > >>> > >>> 1de157d718f6494 6eb8b571283e64e96ca1 > >>> --------------- ------------------------- > >>> 1943 ~ 3% -7.8% 1792 ~ 4% kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd > >>> 1943 -7.8% 1792 TOTAL vmstat.system.cs > >>> > >>> kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd: vmstat.system.cs > >>> > >>> 2050 ++------------------------------------------------------------------+ > >>> | ........*................*..... | > >>> 2000 ++ .*........ ... | > >>> 1950 ++ .... ... | > >>> | ... .... | > >>> 1900 ++ ... .| > >>> 1850 ++.... O O * > >>> *. | > >>> 1800 ++ O O > >>> 1750 ++ | > >>> | | > >>> 1700 ++ | > >>> 1650 O+ | > >>> | | > >>> 1600 ++------------------------------------------------------------------+ > >>> > >>> > >>> 1de157d718f6494 6eb8b571283e64e96ca1 > >>> --------------- ------------------------- > >>> 1216177 ~ 3% -9.4% 1101605 ~ 7% kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd > >>> 1216177 -9.4% 1101605 TOTAL perf-stat.context-switches > >>> > >>> kbuildx/micro/dd-write/4HDD-JBOD-cfq-ext4-10dd: perf-stat.context-switches > >>> > >>> 1.3e+06 ++--------------------------------------------------------------+ > >>> | ..*............... | > >>> 1.25e+06 ++ ...... *...............*....... | > >>> | ..... ...... | > >>> 1.2e+06 *+. O ..| > >>> 1.15e+06 ++ O * > >>> | O | > >>> 1.1e+06 ++ | > >>> | O > >>> 1.05e+06 ++ | > >>> 1e+06 ++ | > >>> | | > >>> 950000 O+ | > >>> | | > >>> 900000 ++--------------------------------------------------------------+ > >>> > >>> > >> > >> > >> -- > >> Thanks > >> Alex > > > -- > Thanks > Alex
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