Re: [PATCH 2/3] vmscan: make mapped executable pages the first class citizen
From: Nai Xia
Date: Mon Jun 08 2009 - 13:25:54 EST
On Mon, Jun 8, 2009 at 3:39 PM, Wu Fengguang<fengguang.wu@xxxxxxxxx> wrote:
> On Wed, May 20, 2009 at 07:20:24PM +0800, Andi Kleen wrote:
>> One scenario that might be useful to test is what happens when some very large
>> processes, all mapped and executable exceed memory and fight each other
>> for the working set. Do you have regressions then compared to without
>> the patches?
>
> I managed to carry out some stress tests for memory tight desktops.
> The outcome is encouraging: clock time and major faults are reduced
> by 50%, and pswpin numbers are reduced to ~1/3.
>
> Here is the test scenario.
> - nfsroot gnome desktop with 512M physical memory
> - run some programs, and switch between the existing windows after
> starting each new program.
I think this is a story of VM_EXEC pages fighting against other kind of pages,
but as Andi said, did you test real regression case of VM_EXEC pages fighting
against each other?
"
One scenario that might be useful to test is what happens when some very large
processes, all mapped and executable exceed memory and fight each other
for the working set. Do you have regressions then compared to without
the patches?
-Andi
"
My experices with Compcache(http://code.google.com/p/compcache/) show that
it also has similar improvement in similar case on LTSP
(http://code.google.com/p/compcache/wiki/Performance).
But it does has a non-trivial performance loss even when doing kernel
compilation.
I am not a little surprised when Andrew said it "There must be some cost
somewhere".
So you have found the spots where your patch doing great,
make double sure it will not do something bad in all places,
and that will be perfect. :-)
>
> The progress timing (seconds) is:
>
> before after programs
> 0.02 0.02 N xeyes
> 0.75 0.76 N firefox
> 2.02 1.88 N nautilus
> 3.36 3.17 N nautilus --browser
> 5.26 4.89 N gthumb
> 7.12 6.47 N gedit
> 9.22 8.16 N xpdf /usr/share/doc/shared-mime-info/shared-mime-info-spec.pdf
> 13.58 12.55 N xterm
> 15.87 14.57 N mlterm
> 18.63 17.06 N gnome-terminal
> 21.16 18.90 N urxvt
> 26.24 23.48 N gnome-system-monitor
> 28.72 26.52 N gnome-help
> 32.15 29.65 N gnome-dictionary
> 39.66 36.12 N /usr/games/sol
> 43.16 39.27 N /usr/games/gnometris
> 48.65 42.56 N /usr/games/gnect
> 53.31 47.03 N /usr/games/gtali
> 58.60 52.05 N /usr/games/iagno
> 65.77 55.42 N /usr/games/gnotravex
> 70.76 61.47 N /usr/games/mahjongg
> 76.15 67.11 N /usr/games/gnome-sudoku
> 86.32 75.15 N /usr/games/glines
> 92.21 79.70 N /usr/games/glchess
> 103.79 88.48 N /usr/games/gnomine
> 113.84 96.51 N /usr/games/gnotski
> 124.40 102.19 N /usr/games/gnibbles
> 137.41 114.93 N /usr/games/gnobots2
> 155.53 125.02 N /usr/games/blackjack
> 179.85 135.11 N /usr/games/same-gnome
> 224.49 154.50 N /usr/bin/gnome-window-properties
> 248.44 162.09 N /usr/bin/gnome-default-applications-properties
> 282.62 173.29 N /usr/bin/gnome-at-properties
> 323.72 188.21 N /usr/bin/gnome-typing-monitor
> 363.99 199.93 N /usr/bin/gnome-at-visual
> 394.21 206.95 N /usr/bin/gnome-sound-properties
> 435.14 224.49 N /usr/bin/gnome-at-mobility
> 463.05 234.11 N /usr/bin/gnome-keybinding-properties
> 503.75 248.59 N /usr/bin/gnome-about-me
> 554.00 276.27 N /usr/bin/gnome-display-properties
> 615.48 304.39 N /usr/bin/gnome-network-preferences
> 693.03 342.01 N /usr/bin/gnome-mouse-properties
> 759.90 388.58 N /usr/bin/gnome-appearance-properties
> 937.90 508.47 N /usr/bin/gnome-control-center
> 1109.75 587.57 N /usr/bin/gnome-keyboard-properties
> 1399.05 758.16 N : oocalc
> 1524.64 830.03 N : oodraw
> 1684.31 900.03 N : ooimpress
> 1874.04 993.91 N : oomath
> 2115.12 1081.89 N : ooweb
> 2369.02 1161.99 N : oowriter
>
> Note that the oo* commands are actually commented out.
>
> The vmstat numbers are (some relevant ones are marked with *):
>
> before after
> nr_free_pages 1293 3898
> nr_inactive_anon 59956 53460
> nr_active_anon 26815 30026
> nr_inactive_file 2657 3218
> nr_active_file 2019 2806
> nr_unevictable 4 4
> nr_mlock 4 4
> nr_anon_pages 26706 27859
> *nr_mapped 3542 4469
> nr_file_pages 72232 67681
> nr_dirty 1 0
> nr_writeback 123 19
> nr_slab_reclaimable 3375 3534
> nr_slab_unreclaimable 11405 10665
> nr_page_table_pages 8106 7864
> nr_unstable 0 0
> nr_bounce 0 0
> *nr_vmscan_write 394776 230839
> nr_writeback_temp 0 0
> numa_hit 6843353 3318676
> numa_miss 0 0
> numa_foreign 0 0
> numa_interleave 1719 1719
> numa_local 6843353 3318676
> numa_other 0 0
> *pgpgin 5954683 2057175
> *pgpgout 1578276 922744
> *pswpin 1486615 512238
> *pswpout 394568 230685
> pgalloc_dma 277432 56602
> pgalloc_dma32 6769477 3310348
> pgalloc_normal 0 0
> pgalloc_movable 0 0
> pgfree 7048396 3371118
> pgactivate 2036343 1471492
> pgdeactivate 2189691 1612829
> pgfault 3702176 3100702
> *pgmajfault 452116 201343
> pgrefill_dma 12185 7127
> pgrefill_dma32 334384 653703
> pgrefill_normal 0 0
> pgrefill_movable 0 0
> pgsteal_dma 74214 22179
> pgsteal_dma32 3334164 1638029
> pgsteal_normal 0 0
> pgsteal_movable 0 0
> pgscan_kswapd_dma 1081421 1216199
> pgscan_kswapd_dma32 58979118 46002810
> pgscan_kswapd_normal 0 0
> pgscan_kswapd_movable 0 0
> pgscan_direct_dma 2015438 1086109
> pgscan_direct_dma32 55787823 36101597
> pgscan_direct_normal 0 0
> pgscan_direct_movable 0 0
> pginodesteal 3461 7281
> slabs_scanned 564864 527616
> kswapd_steal 2889797 1448082
> kswapd_inodesteal 14827 14835
> pageoutrun 43459 21562
> allocstall 9653 4032
> pgrotated 384216 228631
> htlb_buddy_alloc_success 0 0
> htlb_buddy_alloc_fail 0 0
> unevictable_pgs_culled 0 0
> unevictable_pgs_scanned 0 0
> unevictable_pgs_rescued 0 0
> unevictable_pgs_mlocked 4 4
> unevictable_pgs_munlocked 0 0
> unevictable_pgs_cleared 0 0
> unevictable_pgs_stranded 0 0
> unevictable_pgs_mlockfreed 0 0
>
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