Re: [3.6 regression?] THP + migration/compaction livelock (I think)

From: Marc Duponcheel
Date: Fri Nov 16 2012 - 19:24:56 EST


Hi David, others

Results seem OK

recap: I have 2 6core 64bit opterons and I make -j13

I do

# echo always >/sys/kernel/mm/transparent_hugepage/enabled
# while [ 1 ]
do
sleep 10
date
echo = vmstat
egrep "(thp|compact)" /proc/vmstat
echo = khugepaged stack
cat /proc/501/stack
done > /tmp/49361.xxxx
# emerge icedtea
(where 501 = pidof khugepaged)

for xxxx = base = 3.6.6
and xxxx = test = 3.6.6 + diff you provided

I attach
/tmp/49361.base.gz
and
/tmp/49361.test.gz

Note:

with xxx=base, I could see
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
8617 root 20 0 3620m 41m 10m S 988.3 0.5 6:19.06 javac
1 root 20 0 4208 588 556 S 0.0 0.0 0:03.25 init
already during configure and I needed to kill -9 javac

with xxx=test, I could see
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
9275 root 20 0 2067m 474m 10m S 304.2 5.9 0:32.81 javac
710 root 0 -20 0 0 0 S 0.3 0.0 0:01.07 kworker/0:1H
later when processing >700 java files

Also note that with xxx=test compact_blocks_moved stays 0

hope this helps

Thanks

have a nice day

On 2012 Nov 15, Marc Duponcheel wrote:
> Hi David
>
> Thanks for the changeset
>
> I will test 3.6.6 without&with this weekend.
>
> Have a nice day

--
Marc Duponcheel
Velodroomstraat 74 - 2600 Berchem - Belgium
+32 (0)478 68.10.91 - marc@xxxxxxxxxx

Attachment: 49361.base.gz
Description: Binary data

Attachment: 49361.test.gz
Description: Binary data