Re: [PATCH] coredump: fix pipe coredump when core limit is 0

[Jovi Zhang]

2011/8/23 Oleg Nesterov <oleg@xxxxxxxxxx>:
> On 08/22, PÃdraig Brady wrote:
>>
>> On 08/21/2011 11:36 PM, Neil Horman wrote:
>> > Concur. ÂThe comment should be changed
>> > Neil
>> >
>> > Oleg Nesterov <oleg@xxxxxxxxxx> wrote:
>> >
>> >> On 08/21, Oleg Nesterov wrote:
>> >>>
>> >>> On 08/21, bookjovi@xxxxxxxxx wrote:
>> >>>>
>> >>>> For non-pipe case, limit 0 also means drop the coredump, so just put
>> >>>> the zero limit check at do_coredump function begining.
>> >>>
>> >>> Neil, what do you think? Should we change the code or the comment?
>> >>
>> >> Personally I think we should fix the comment. I think RLIMIT_CORE
>> >> doesn't apply in this case, limit == 1 check is very special. And
>> >> this is what linux always did, except between 725eae32 and 898b374a.
>>
>> Sorry for jumping in late here.
>> I would really like `ulimit -c 0` to completely disable core dumps,
>> including not running core_pattern, as I also mentioned here:
>> https://bugs.launchpad.net/ubuntu/+source/apport/+bug/62511
>> I noticed this in a script where ctrl-\ was taking a long
>> time to be registered as the core_pattern was run unconditionally.
>
> May be. As I said, I do not really know and personally I agree with
> everything. My only point was, this is not the bug, this is what we
> always did.
>
> This is up to Neil, I think.
>
> Oleg.
>
>
Well, so here have two questions.
1) That comments "but a limit of 0 skips the dump" definitely is wrong
right now, it don't match with reality.
2) In ispipe case, core limit 0 should skip the dump or not? this need
more discussion.
 Âfrom pipe coredump point of view, core limit is irrelevant, it
doesn't write to file system.
 Âfrom user point of view, there will be a lot of core files if we
let core limit 0 create core file, user might be boring.

I fix the comments part by below patch(thanks Oleg's comments), please
use attachment patch when merge.