[Mageia-sysadm] 2010.1 kernel with the vmscan fix

[Buchan Milne]

On Sunday, 24 October 2010 07:28:55 Thomas Backlund wrote:
> Hi,
> there is now a kernel-2.6.33.7-2.1mnb for 2010.1 at:
> 
> http://tmb.mine.nu/Mandriva/2010.1/
> http://tmb2.mine.nu/Mandriva/2010.1/
> 
> With the fix:
> - vmscan: raise the bar to PAGEOUT_IO_SYNC stalls
>    (Fixes "system goes unresponsive under memory pressure and lots of
>     dirty/writeback pages" bug. (http://lkml.org/lkml/2010/4/4/86))
> 
> 
> This was also suggested by blino to help the BS

This is definitely a huge improvement:

[root at tiger ~]# uname -r
2.6.33.7-desktop-2.1mnb
[root at tiger ~]# time dd if=/media/smartdrive/isos/mandriva/mandriva-linux-
free-2010-spring-i586/mandriva-linux-free-2010-spring-i586.iso 
of=/dev/sdc;uptime
9107456+0 records in
9107456+0 records out
4663017472 bytes (4.7 GB) copied, 7075.81 s, 659 kB/s
4.83user 60.63system 1:57:55elapsed 0%CPU (0avgtext+0avgdata 3216maxresident)k
18186800inputs+9107456outputs (1major+260minor)pagefaults 0swaps
 11:38:07 up 17:35, 21 users,  load average: 4.57, 5.00, 5.23

While this was running, the system was quite responsive, in fact I didn't 
notice that it was under load, whereas before, with dd'ing an ISO from a USB 
hard drive to a slow USB flash disk, load average was higher, and my system 
was almost unusable (even just switching between running applications was 
tedious). Unfortunately, due to a 20-month-old having learned how to operate 
switches, I booted into this kernel without notice, so I didn't validate my 
previous experience on the previous kernel with exactly the same operation, 
but I am quite sure I have experienced it before on 2.6.33.x.

Regards,
Buchan