lkml.org 
[lkml]   [2013]   [Sep]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: ipc-msg broken again on 3.11-rc7?
On 09/03/2013 10:44 AM, Vineet Gupta wrote:
>> b) Could you check that it is not just a performance regression?
>> Does ./msgctl08 1000 16 hang, too?
> Nope that doesn't hang. The minimal configuration that hangs reliably is msgctl
> 50000 2
>
> With this config there are 3 processes.
> ...
> 555 554 root S 1208 0.4 0 0.0 ./msgctl08 50000 2
> 554 551 root S 1208 0.4 0 0.0 ./msgctl08 50000 2
> 551 496 root S 1208 0.4 0 0.0 ./msgctl08 50000 2
> ...
>
> [ARCLinux]$ cat /proc/551/stack
> [<80aec3c6>] do_wait+0xa02/0xc94
> [<80aecad2>] SyS_wait4+0x52/0xa4
> [<80ae24fc>] ret_from_system_call+0x0/0x4
>
> [ARCLinux]$ cat /proc/555/stack
> [<80c2950e>] SyS_msgrcv+0x252/0x420
> [<80ae24fc>] ret_from_system_call+0x0/0x4
>
> [ARCLinux]$ cat /proc/554/stack
> [<80c28c82>] do_msgsnd+0x116/0x35c
> [<80ae24fc>] ret_from_system_call+0x0/0x4
>
> Is this a case of lost wakeup or some such. I'm running with some more diagnostics
> and will report soon ...
What is the output of ipcs -q? Is the queue full or empty when it hangs?
I.e. do we forget to wake up a receiver or forget to wake up a sender?

--
Manfred


\
 
 \ /
  Last update: 2013-09-03 11:21    [W:0.102 / U:0.080 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site