[pacman-dev] pacman -Qs first-run performance

[Philipp Überbacher]

Excerpts from Philipp Überbacher's message of 2011-09-01 21:03:47 +0200:
> Excerpts from Dan McGee's message of 2011-09-01 20:41:27 +0200:
> > On Thu, Sep 1, 2011 at 1:22 PM, Philipp Überbacher
> > <hollunder at lavabit.com> wrote:
> > > Excerpts from Dan McGee's message of 2011-09-01 19:54:34 +0200:
> > >  free -m
> > >             total       used       free     shared    buffers     cached
> > > Mem:          2002       1080        922          0         17        299
> > > -/+ buffers/cache:        763       1239
> > > Swap:         2055         98       1956
> > Wow- what are you running on a laptop that is keeping 763 MB of RAM
> > pegged? Although there appears to be something else in play here.
> 
> At least half of that is due to firefox, a music player with a lot of
> songs in the playlist (aqualung), smplayer and the mail client (sup)
> should account for most of the rest.
> 
> > >  hdparm -Tt /dev/sda
> > >
> > > /dev/sda:
> > >  Timing cached reads:   1426 MB in  2.00 seconds = 712.73 MB/sec
> > >  Timing buffered disk reads: 166 MB in  3.01 seconds =  55.09 MB/sec
> > This is a bit slow, but nothing that should impact your performance that much.
> > 
> > >  echo 3 > /proc/sys/vm/drop_caches; time pacman -Qs foobarbaz; time pacman -Qs foobarbaz
> > >
> > > real    1m45.235s
> > > user    0m0.127s
> > > sys     0m0.590s
> > >
> > > real    0m0.097s
> > > user    0m0.043s
> > > sys     0m0.023s
> > Can you repeat this and use /usr/bin/time instead of just plain
> > "time"? You may have to install the "time" package.
> 
> Ah, yes, that was necessary for /usr/bin/time to work.
> 
> > echo 3 > /proc/sys/vm/drop_caches; /usr/bin/time pacman -Qs foobarbaz;
> > /usr/bin/time pacman -Qs foobarbaz
> 
>  echo 3 > /proc/sys/vm/drop_caches; /usr/bin/time pacman -Qs foobarbaz; /usr/bin/time pacman -Qs foobarbaz
> Command exited with non-zero status 1
> 0.08user 0.62system 0:48.48elapsed 1%CPU (0avgtext+0avgdata 3428maxresident)k
> 173016inputs+0outputs (16major+2353minor)pagefaults 0swaps
> Command exited with non-zero status 1
> 0.02user 0.03system 0:00.08elapsed 78%CPU (0avgtext+0avgdata 3428maxresident)k
> 0inputs+0outputs (0major+2369minor)pagefaults 0swaps
> 
>  echo 3 > /proc/sys/vm/drop_caches; /usr/bin/time pacman -Ss foobarbaz; /usr/bin/time pacman -Ss foobarbaz
> Command exited with non-zero status 1
> 0.19user 0.03system 0:01.51elapsed 14%CPU (0avgtext+0avgdata 8440maxresident)k
> 9864inputs+0outputs (16major+2177minor)pagefaults 0swaps
> Command exited with non-zero status 1
> 0.19user 0.01system 0:00.27elapsed 76%CPU (0avgtext+0avgdata 8444maxresident)k
> 0inputs+0outputs (0major+2194minor)pagefaults 0swaps
> 
> > Once you do that (but please get the numbers first!), try running
> > `pacman-optimize` then rerunning the above test.
> 
>  echo 3 > /proc/sys/vm/drop_caches; /usr/bin/time pacman -Qs foobarbaz; /usr/bin/time pacman -Qs foobarbaz
> Command exited with non-zero status 1
> 0.07user 0.46system 0:30.68elapsed 1%CPU (0avgtext+0avgdata 3428maxresident)k
> 31752inputs+0outputs (16major+2353minor)pagefaults 0swaps
> Command exited with non-zero status 1
> 0.02user 0.04system 0:00.09elapsed 74%CPU (0avgtext+0avgdata 3428maxresident)k
> 0inputs+0outputs (0major+2369minor)pagefaults 0swaps
> 
>  echo 3 > /proc/sys/vm/drop_caches; /usr/bin/time pacman -Ss foobarbaz; /usr/bin/time pacman -Ss foobarbaz
> Command exited with non-zero status 1
> 0.19user 0.02system 0:01.57elapsed 14%CPU (0avgtext+0avgdata 8440maxresident)k
> 8832inputs+0outputs (16major+2178minor)pagefaults 0swaps
> Command exited with non-zero status 1
> 0.20user 0.00system 0:00.26elapsed 80%CPU (0avgtext+0avgdata 8440maxresident)k
> 0inputs+0outputs (0major+2193minor)pagefaults 0swaps
>  
> > Finally, what is the output of df -h for whatever drive /var/lib is
> > on? Is it near capacity? And what filesystem with what mount options?
> 
> from df -h
> /dev/disk/by-uuid/456aa338-0417-43ca-85b2-a03d1b36ec1e ext4       21G   13G  6.2G  68% /
> 
> from mtab
> /dev/disk/by-uuid/456aa338-0417-43ca-85b2-a03d1b36ec1e / ext4 rw,noatime,user_xattr,acl,barrier=1,nodelalloc,data=ordered 0 0
> 
> > >  echo 3 > /proc/sys/vm/drop_caches; time pacman -Ss foobarbaz; time pacman -Ss foobarbaz
> > >
> > > real    0m1.299s
> > > user    0m0.200s
> > > sys     0m0.023s
> > >
> > > real    0m0.252s
> > > user    0m0.200s
> > > sys     0m0.010s
> > 
> > At least this one is OK.
> > 
> > -Dan
> 
> Ok, thanks a lot Dan and everyone else.
> 
> Regards,
> Philipp

So what do you guys think,
is it simply the combination of slow HD and many packages or is there
something wrong with my system that could be fixed by changing some
config?

Regards,
Philipp