yum 3.2.23 more than 10x slower than 3.2.21?!

[Roberto Ragusa]

Hi,

yum got really slower a few days ago on F10, so I investigated and found that:

(3.2.23) #yum list updates
real    1m28.446s
user    1m24.553s
sys     0m0.546s

(3.2.21) #yum list updates
real    0m7.621s
user    0m6.673s
sys     0m0.390s

this is with a few repositories, no net access, no disk access (everything
is cached), trivially reproduceable. No yum plugins (just downloadonly), no
PackageKit installed.

About 90 seconds of 100% CPU (2.4GHz Core 2) is a disaster.

What the ${REPLACE_WITH_RUDE_WORD} is it the new version doing?
Is it raytracing something in background? :-)
A quick strace of the process appeared to be read()ing a lot of stuff
and gettimeofday()ing a lot.

gettimeofday({1246010546, 912877}, NULL) = 0
pread64(29, "\0\0\0\0\1\0\0\0A\35\0\0\0\0\0\0B\35\0\0\1\0\346?\0\7\0\0\0B\0\0E"..., 16384, 122699776) = 16384
pread64(29, "\0\0\0\0\1\0\0\0B\35\0\0A\35\0\0\0\0\0\0\1\0F\t\0\7\0\0\0\0\0\0\0"..., 16384, 122716160) = 16384
gettimeofday({1246010546, 913336}, NULL) = 0
gettimeofday({1246010546, 913696}, NULL) = 0
pread64(29, "\0\0\0\0\1\0\0\0\243\1\0\0\0\0\0\0^\25\0\0\1\0\346?\0\7\0\0\0G\0\0="..., 16384, 6864896) = 16384
pread64(29, "\0\0\0\0\1\0\0\0^\25\0\0\243\1\0\0\0\0\0\0\1\0\306\1\0\7\0cpio\0g"..., 16384, 89620480) = 16384
gettimeofday({1246010546, 926442}, NULL) = 0
gettimeofday({1246010546, 926872}, NULL) = 0
pread64(29, "\0\0\0\0\1\0\0\0\335\23\0\0\0\0\0\0\375\32\0\0\1\0\346?\0\7\0\0\0H\0\1l"..., 16384, 83312640) = 16384
pread64(29, "\0\0\0\0\1\0\0\0\375\32\0\0\335\23\0\0\235\32\0\0\1\0\346?\0\007202c8e5"..., 16384, 113197056) = 16384
pread64(29, "\0\0\0\0\1\0\0\0\235\32\0\0\375\32\0\0^\33\0\0\1\0\346?\0\7\377\377\377\377\377\377\377"..., 16384, 111624192) = 16384
pread64(29, "\0\0\0\0\1\0\0\0^\33\0\0\235\32\0\0^\35\0\0\1\0\346?\0\7\0- Add "..., 16384, 114786304) = 16384

Can someone else reproduce this?
I'm not an expert at profiling python.

Best regards.
-- 
   Roberto Ragusa    mail at robertoragusa.it