lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Sun, 31 Aug 2008 10:51:46 +0200
From:	"Dushan Tcholich" <dusanc@...il.com>
To:	"Francois Romieu" <romieu@...zoreil.com>
Cc:	"Robert Hancock" <hancockr@...w.ca>, netdev@...r.kernel.org,
	LKML <linux-kernel@...r.kernel.org>
Subject: Re: ksoftirqd high cpu load on kernels 2.6.24 to 2.6.27-rc1-mm1

Hello
I found the culprit.

When using powertop I get:
Top causes for wakeups:
  35,2% (251,0)                ip : br_stp_enable_bridge (br_hello_timer_expired

So I tried to turn them off with:
brctl sethello br0 0
but the problem persisted.
If I do
brctl sethello br0 5
context switch rate drops 200 times and problem is gone.
I think that the command brctl sethello br0 0 doesn't turn off hello
messages, but sends them 250 times per second.

Thanks for your time
Dushan
On Sat, Aug 30, 2008 at 3:48 AM, Dushan Tcholich <dusanc@...il.com> wrote:
> Hello again
>
>
> On Mon, Aug 11, 2008 at 9:53 AM, Dushan Tcholich <dusanc@...il.com> wrote:
>> Hi
>>
>> On Sun, Aug 10, 2008 at 9:00 PM, Dushan Tcholich <dusanc@...il.com> wrote:
>>> Hi
>>> Sorry for answering this late, but I was short on time and couldn't
>>> get reiser4 to work with 2.6.27-rc2
>>>
>>> On Thu, Aug 7, 2008 at 8:58 PM, Francois Romieu <romieu@...zoreil.com> wrote:
>>>> Dushan Tcholich <dusanc@...il.com> :
>>>> [...]
>>>>> I googled a little and found out that oprofile is a little above my head.
>>>>> So as I thought that some driver or HW might be responsible for this I
>>>>> tried to disable various onboard HW and found out that if I disable
>>>>> onboard ethernet problem dissapears, so now I've added netdev and
>>>>> maintainer of R8169 driver to cc.
>>>>
>>>> Can you try 2.6.27-rc2 and send the content of /proc/interrupts, dmesg,
>>>> ifconfig as well as a capture of the strange output from top ?
>>>>
>>
>> I tried some more kernels and I had the same problem with 2.6.23.17
>> and 2.6.27-rc1-mm1, but I couldn't reproduce it with kernel from
>> sysresccd 1.0.1 http://www.sysresccd.org/ which is a patched version
>> of 2.6.24 i think .7 when I booted it to change fs.
>> Could it be that something in userspace is creating this?
>>
>
> I dug a little more and found out some new info.
> Unsolved bugreport with same symptoms:
> http://marc.info/?l=linux-kernel&m=119613299024398&w=2
> Problems appear if I start br0 interface, as context switch rate
> increases 200 times. If I start eth0 instead everything looks ok.
> The bugreport above had bridging enabled too.
>
> When using eth0 I get:
>  vmstat -n 1 10
> procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu----
>  r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs us sy id wa
>  2  0  17720 162288  25024 576852    0    0    21    22    6    9 10  4 85  0
>  0  0  17720 162196  25024 576880    0    0     0     0   13  473  0  0 99  0
>  0  0  17720 162196  25028 576880    0    0     0     4   36 1122  1  0 99  0
>  0  0  17720 162196  25028 576880    0    0     0     0   83  844  0  0 99  0
>  0  0  17720 162196  25028 576880    0    0     0     0   55  691  1  0 99  0
>  0  0  17720 162556  25028 576880    0    0     0     0   13  490  1  0 100  0
>  0  0  17720 162100  25028 576880    0    0     0     0   39  561  6  0 94  0
>  1  0  17720 162028  25028 576880    0    0     0     0   16 1030  4  0 96  0
>  0  0  17720 162028  25028 576880    0    0     0     0   40  597  1  0 99  0
>  0  0  17720 162028  25028 576880    0    0     0     0   12  512  2  0 97  0
>
>  top
>
> top - 03:30:07 up 6 days,  5:40,  4 users,  load average: 0.02, 0.11, 0.28
> Tasks: 149 total,   2 running, 147 sleeping,   0 stopped,   0 zombie
> Cpu(s): 12.1%us,  3.3%sy,  0.0%ni, 84.6%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
> Mem:   1033388k total,   871336k used,   162052k free,    25016k buffers
> Swap:   610460k total,    17720k used,   592740k free,   576852k cached
>
>  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
>
>    4 root      15  -5     0    0    0 S    0  0.0 554:23.44 ksoftirqd/0
>
> If I use br0 I get:
>  vmstat -n 1 10
> procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu----
>  r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs us sy id wa
>  0  0  17720 162112  25048 577120    0    0    21    22    6   11 10  4 86  0
>  0  0  17720 162152  25048 577120    0    0     0     0   14 111082  0  3 97  0
>  0  0  17720 162152  25048 577120    0    0     0     0   23 107134  1  3 96  0
>  1  0  17720 160148  25048 577120    0    0     0     0   11 109888  2  3 95  0
>  0  0  17720 162032  25048 577120    0    0     0     0   33 108163  1  2 97  0
>  0  0  17720 162032  25048 577120    0    0     0     0    7 104642  2  2 95  0
>  0  0  17720 162020  25048 577120    0    0     0     0   41 109135  0  2 98  0
>  0  0  17720 162036  25048 577120    0    0     0     0    9 105133  0  3 96  0
>  0  0  17720 162020  25048 577120    0    0     0     0   42 107605  1  2 97  0
>  1  0  17720 162032  25048 577120    0    0     0     0    5 110768  0  2 98  0
>
> top
>
> top - 03:32:03 up 6 days,  5:41,  4 users,  load average: 0.09, 0.10, 0.26
> Tasks: 148 total,   2 running, 146 sleeping,   0 stopped,   0 zombie
> Cpu(s):  4.8%us,  2.0%sy,  0.0%ni, 93.0%id,  0.0%wa,  0.0%hi,  0.2%si,  0.0%st
> Mem:   1033388k total,   871564k used,   161824k free,    25048k buffers
> Swap:   610460k total,    17720k used,   592740k free,   577120k cached
>
>  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
> 11489 dusan     20   0  235m  85m  24m R    6  8.5   1:03.51 firefox
>    4 root      15  -5     0    0    0 S   7  0.0 554:24.04 ksoftirqd/0
>
> I start br0 like this in /etc/conf.d/net
>
> bridge_br0="eth0"
> config_eth0=( "null" )
> config_br0=( "192.168.1.3/24" )
> RC_NEED_br0="net.eth0"
> brctl_br0=( "setfd 0" "sethello 0" "stp off" )
> #routes_br0=( "default gw 192.168.1.3" )
> depend_br0() {
>        need net.eth0
> }
>
> I start eth0 like this in /etc/conf.d/net
> config_eth0=( "192.168.1.3/24" )
>
>>> I've copied my root to ext3 partition and with vanilla 2.6.27-rc2 I got:
>>> -With my .config problem is still here
>>> -With only rtl8169 removed from config there is no problem
>>>
>>>> It seems rather benign though.
>>>>
>>> Well I wouldn't agree from power managment standpoint :). This nic is
>>> in a lot of laptops.
>>> 8% of 2.13GHz Core2Duo CPU is a lot :)
>>>
>>> Btw. should LKML be removed from cc?
>>> If you need any more help please ask.
>>> I hope I'm not harrasing you too much :)
>>>> --
>>>> Ueimor
>>>>
>>> Have a nice day
>>> Dushan
>>>
>> ...
>>
> Have a nice day
> Dushan
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ