* core man page %e
@ 2020-05-30 10:39 Jonny Grant
2020-06-01 10:21 ` Jonny Grant
2020-06-09 10:18 ` Michael Kerrisk (man-pages)
0 siblings, 2 replies; 6+ messages in thread
From: Jonny Grant @ 2020-05-30 10:39 UTC (permalink / raw)
To: Michael Kerrisk, linux-man
Hello mtk
I've noticed "%e-%s.core" often gives something other than the filename and the name is truncated to 16 bytes:-
ThreadPoolServi-5.core
Chrome_InProcUt-5.core
This was set:
sysctl -w kernel.core_pattern="%e-%s.core"
In multithreaded applications it looks like %e is giving something other than the filename, perhaps a thread entry-point
symbol name.
https://www.man7.org/linux/man-pages/man5/core.5.html
%e executable filename (without path prefix)
Could this be updated to:
%e executable filename or thread name truncated to 16 bytes
Cheers, Jonny
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: core man page %e
2020-05-30 10:39 core man page %e Jonny Grant
@ 2020-06-01 10:21 ` Jonny Grant
2020-06-09 8:25 ` Michael Kerrisk (man-pages)
2020-06-09 10:18 ` Michael Kerrisk (man-pages)
1 sibling, 1 reply; 6+ messages in thread
From: Jonny Grant @ 2020-06-01 10:21 UTC (permalink / raw)
To: Michael Kerrisk, linux-man
Hi Mtk,
BTW, if I add "%P-%e-%s.core" every core starts with the same
"P1000-"
The man page shows:
%P PID of dumped process, as seen in the initial PID namespace
(since Linux 3.12)
Do you see similar? I was only needing something to make the filename unique, so %t is enough.
Cheers, Jonny
On 30/05/2020 11:39, Jonny Grant wrote:
> Hello mtk
>
> I've noticed "%e-%s.core" often gives something other than the filename and the name is truncated to 16 bytes:-
>
> ThreadPoolServi-5.core
> Chrome_InProcUt-5.core
>
> This was set:
> sysctl -w kernel.core_pattern="%e-%s.core"
>
>
>
> In multithreaded applications it looks like %e is giving something other than the filename, perhaps a thread entry-point
> symbol name.
>
> https://www.man7.org/linux/man-pages/man5/core.5.html
>
> %e executable filename (without path prefix)
>
> Could this be updated to:
>
> %e executable filename or thread name truncated to 16 bytes
>
> Cheers, Jonny
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: core man page %e
2020-06-01 10:21 ` Jonny Grant
@ 2020-06-09 8:25 ` Michael Kerrisk (man-pages)
2020-06-09 11:00 ` Jonny Grant
0 siblings, 1 reply; 6+ messages in thread
From: Michael Kerrisk (man-pages) @ 2020-06-09 8:25 UTC (permalink / raw)
To: Jonny Grant, linux-man; +Cc: mtk.manpages
On 6/1/20 12:21 PM, Jonny Grant wrote:
> Hi Mtk,
>
> BTW, if I add "%P-%e-%s.core" every core starts with the same
> "P1000-"
>
> The man page shows:
> %P PID of dumped process, as seen in the initial PID namespace
> (since Linux 3.12)
>
> Do you see similar? I was only needing something to make the filename
> unique, so %t is enough.
I don't see the same. What do you see when you verify the change with:
sysctl kernel.core_pattern
Thanks,
Michael
--
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: core man page %e
2020-06-09 8:25 ` Michael Kerrisk (man-pages)
@ 2020-06-09 11:00 ` Jonny Grant
0 siblings, 0 replies; 6+ messages in thread
From: Jonny Grant @ 2020-06-09 11:00 UTC (permalink / raw)
To: Michael Kerrisk (man-pages), linux-man
On 09/06/2020 09:25, Michael Kerrisk (man-pages) wrote:
> On 6/1/20 12:21 PM, Jonny Grant wrote:
>> Hi Mtk,
>>
>> BTW, if I add "%P-%e-%s.core" every core starts with the same
>> "P1000-"
>>
>> The man page shows:
>> %P PID of dumped process, as seen in the initial PID namespace
>> (since Linux 3.12)
>>
>> Do you see similar? I was only needing something to make the filename
>> unique, so %t is enough.
> I don't see the same. What do you see when you verify the change with:
>
> sysctl kernel.core_pattern
>
> Thanks,
>
> Michael
>
It must be some mistake I made, can't reproduce it today
Jonny
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: core man page %e
2020-05-30 10:39 core man page %e Jonny Grant
2020-06-01 10:21 ` Jonny Grant
@ 2020-06-09 10:18 ` Michael Kerrisk (man-pages)
2020-06-09 11:35 ` Jonny Grant
1 sibling, 1 reply; 6+ messages in thread
From: Michael Kerrisk (man-pages) @ 2020-06-09 10:18 UTC (permalink / raw)
To: Jonny Grant, linux-man; +Cc: mtk.manpages
Hello Jonny,
On 5/30/20 12:39 PM, Jonny Grant wrote:
> Hello mtk
>
> I've noticed "%e-%s.core" often gives something other than the
> filename and the name is truncated to 16 bytes:-
>
> ThreadPoolServi-5.core
> Chrome_InProcUt-5.core
>
> This was set:
> sysctl -w kernel.core_pattern="%e-%s.core"
>
>
>
> In multithreaded applications it looks like %e is giving something
> other than the filename, perhaps a thread entry-point symbol name.>
> https://www.man7.org/linux/man-pages/man5/core.5.html
>
> %e executable filename (without path prefix)
>
> Could this be updated to:
>
> %e executable filename or thread name truncated to 16 bytes
I changed it to this:
%e The process or thread's comm value, which typically is the
same as the executable filename (without path prefix, and
truncated to a maximum of 15 characters), but may have
been modified to be something different; see the discus‐
sion of /proc/[pid]/comm and /proc/[pid]/task/[tid]/comm
in proc(5).
Thanks,
Michael
--
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: core man page %e
2020-06-09 10:18 ` Michael Kerrisk (man-pages)
@ 2020-06-09 11:35 ` Jonny Grant
0 siblings, 0 replies; 6+ messages in thread
From: Jonny Grant @ 2020-06-09 11:35 UTC (permalink / raw)
To: Michael Kerrisk (man-pages), linux-man
On 09/06/2020 11:18, Michael Kerrisk (man-pages) wrote:
> Hello Jonny,
>
> On 5/30/20 12:39 PM, Jonny Grant wrote:
>> Hello mtk
>>
>> I've noticed "%e-%s.core" often gives something other than the
>> filename and the name is truncated to 16 bytes:-
>>
>> ThreadPoolServi-5.core
>> Chrome_InProcUt-5.core
>>
>> This was set:
>> sysctl -w kernel.core_pattern="%e-%s.core"
>>
>>
>>
>> In multithreaded applications it looks like %e is giving something
>> other than the filename, perhaps a thread entry-point symbol name.>
>> https://www.man7.org/linux/man-pages/man5/core.5.html
>>
>> %e executable filename (without path prefix)
>>
>> Could this be updated to:
>>
>> %e executable filename or thread name truncated to 16 bytes
>
> I changed it to this:
>
> %e The process or thread's comm value, which typically is the
> same as the executable filename (without path prefix, and
> truncated to a maximum of 15 characters), but may have
> been modified to be something different; see the discus‐
> sion of /proc/[pid]/comm and /proc/[pid]/task/[tid]/comm
> in proc(5).
Hi Michael
That looks good.
I saw $ top -H shows these similar 15 byte truncated names. It's a shame it is such a low limit.
19697 jonny 20 0 657252 46120 29096 S 2.6 0.3 0:18.84 gnome-terminal-
19431 jonny 20 0 4823508 114384 75668 S 1.6 0.7 0:00.08 ThreadPoolForeg
Is it better to say "15 bytes" because utf8 binary filenames or thread names would be less characters?
For example:
$ ./おはようございます
$ cat /proc/892/comm
おはようご
That is 15 bytes of utf8
E3 81 8A E3 81 AF E3 82 88 E3 81 86 E3 81 94 0A
Cheers, Jonny
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2020-06-09 11:35 UTC | newest]
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2020-05-30 10:39 core man page %e Jonny Grant
2020-06-01 10:21 ` Jonny Grant
2020-06-09 8:25 ` Michael Kerrisk (man-pages)
2020-06-09 11:00 ` Jonny Grant
2020-06-09 10:18 ` Michael Kerrisk (man-pages)
2020-06-09 11:35 ` Jonny Grant
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