* Re: config PROC_CHILDREN
2015-07-08 14:18 ` Iago López Galeiras
@ 2015-07-08 14:46 ` Cyrill Gorcunov
2015-07-08 14:50 ` Djalal Harouni
2015-07-08 16:34 ` Jean Delvare
2 siblings, 0 replies; 8+ messages in thread
From: Cyrill Gorcunov @ 2015-07-08 14:46 UTC (permalink / raw)
To: Iago López Galeiras
Cc: Jean Delvare, LKML, Djalal Harouni, Alban Crequy, Andrew Morton
On Wed, Jul 08, 2015 at 04:18:28PM +0200, Iago López Galeiras wrote:
...
>
> > That being said, I am curious... Is this interface so expensive that it
> > really deserves a separate option, instead of always enabling it? This
> > seems to be a fairly generic feature that a lot of scripts and tools
> > could benefit from (starting with pstree I suppose.)
>
> I don't think I have enough information to answer that question. I'll CC Cyrill
> Gorcunov and Andrew Morton.
The interface is not expensive per-se but it was developed for
checkpoint/restore in first place so we've been wrapping any
new code created for this sake with CONFIG_. And we (criu
team) were the only users of this interface at those days
so it had lot of sence to keep it conditionally enabled.
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: config PROC_CHILDREN
2015-07-08 14:18 ` Iago López Galeiras
2015-07-08 14:46 ` Cyrill Gorcunov
@ 2015-07-08 14:50 ` Djalal Harouni
2015-07-08 16:33 ` Jean Delvare
2015-07-08 16:34 ` Jean Delvare
2 siblings, 1 reply; 8+ messages in thread
From: Djalal Harouni @ 2015-07-08 14:50 UTC (permalink / raw)
To: Iago López Galeiras
Cc: Jean Delvare, LKML, Djalal Harouni, Alban Crequy,
Cyrill Gorcunov, Andrew Morton
On Wed, Jul 08, 2015 at 04:18:28PM +0200, Iago López Galeiras wrote:
> On 07/04/2015 07:07 PM, Jean Delvare wrote:
> > Hi Iago,
> >
> > Please don't top-post.
> >
> > On Fri, 3 Jul 2015 11:10:45 +0200, Iago López Galeiras wrote:
> >> Hi Jean,
> >>
> >> The purpose of this option is enabling /proc/<pid>/task/<tid>/children without
> >> having to enable CHECKPOINT_RESTORE, which is hidden behind EXPERT.
> >>
> >> Regarding its lack of help, documentation is in already in place[1] but perhaps
> >> that's not clear for the user because as you say the Kconfig help text is missing.
> >>
> >> I suggest adding something like:
> >>
> >> Provides a fast way to retrieve first level children pids of a task. See
> >> <file:Documentation/filesystems/proc.txt> for more information.
> >>
> >> Do you think that's enough?
> >
> > That's a start, the reference to Documentation/filesystems/proc.txt is
> > good but I think we can do better. You need to help the user make the
> > decision. Why should he/she say Y or N? The user should NOT have to look
> > at an external documentation file if the answer is N. I would suggest
> > the following:
> >
> > Say Y if running any user-space software which takes benefit from this
> > interface. For example, rkt is such a piece of software.
>
> That makes it more clear for the user. Thanks!
>
> > That being said, I am curious... Is this interface so expensive that it
> > really deserves a separate option, instead of always enabling it? This
> > seems to be a fairly generic feature that a lot of scripts and tools
> > could benefit from (starting with pstree I suppose.)
>
> I don't think I have enough information to answer that question. I'll CC Cyrill
> Gorcunov and Andrew Morton.
IIRC, this was suggested by Andrew Morton, and it results on this patch.
http://www.spinics.net/lists/linux-fsdevel/msg86491.html
> --
>
> Iago López Galeiras
> Software developer @ Endocode AG
> iago@endocode.com
--
Djalal Harouni
http://opendz.org
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: config PROC_CHILDREN
2015-07-08 14:50 ` Djalal Harouni
@ 2015-07-08 16:33 ` Jean Delvare
0 siblings, 0 replies; 8+ messages in thread
From: Jean Delvare @ 2015-07-08 16:33 UTC (permalink / raw)
To: Djalal Harouni
Cc: Iago López Galeiras, LKML, Djalal Harouni, Alban Crequy,
Cyrill Gorcunov, Andrew Morton
Le Wednesday 08 July 2015 à 15:50 +0100, Djalal Harouni a écrit :
> On Wed, Jul 08, 2015 at 04:18:28PM +0200, Iago López Galeiras wrote:
> > On 07/04/2015 07:07 PM, Jean Delvare wrote:
> > > That being said, I am curious... Is this interface so expensive that it
> > > really deserves a separate option, instead of always enabling it? This
> > > seems to be a fairly generic feature that a lot of scripts and tools
> > > could benefit from (starting with pstree I suppose.)
> >
> > I don't think I have enough information to answer that question. I'll CC Cyrill
> > Gorcunov and Andrew Morton.
> IIRC, this was suggested by Andrew Morton, and it results on this patch.
>
> http://www.spinics.net/lists/linux-fsdevel/msg86491.html
OK, if Andrew said so... :-D
--
Jean Delvare
SUSE L3 Support
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: config PROC_CHILDREN
2015-07-08 14:18 ` Iago López Galeiras
2015-07-08 14:46 ` Cyrill Gorcunov
2015-07-08 14:50 ` Djalal Harouni
@ 2015-07-08 16:34 ` Jean Delvare
2 siblings, 0 replies; 8+ messages in thread
From: Jean Delvare @ 2015-07-08 16:34 UTC (permalink / raw)
To: Iago López Galeiras
Cc: LKML, Djalal Harouni, Alban Crequy, Cyrill Gorcunov, Andrew Morton
Le Wednesday 08 July 2015 à 16:18 +0200, Iago López Galeiras a écrit :
> On 07/04/2015 07:07 PM, Jean Delvare wrote:
> > On Fri, 3 Jul 2015 11:10:45 +0200, Iago López Galeiras wrote:
> >> The purpose of this option is enabling /proc/<pid>/task/<tid>/children without
> >> having to enable CHECKPOINT_RESTORE, which is hidden behind EXPERT.
> >>
> >> Regarding its lack of help, documentation is in already in place[1] but perhaps
> >> that's not clear for the user because as you say the Kconfig help text is missing.
> >>
> >> I suggest adding something like:
> >>
> >> Provides a fast way to retrieve first level children pids of a task. See
> >> <file:Documentation/filesystems/proc.txt> for more information.
> >>
> >> Do you think that's enough?
> >
> > That's a start, the reference to Documentation/filesystems/proc.txt is
> > good but I think we can do better. You need to help the user make the
> > decision. Why should he/she say Y or N? The user should NOT have to look
> > at an external documentation file if the answer is N. I would suggest
> > the following:
> >
> > Say Y if running any user-space software which takes benefit from this
> > interface. For example, rkt is such a piece of software.
>
> That makes it more clear for the user. Thanks!
You're welcome. Will you submit a patch, or should I take care of it?
--
Jean Delvare
SUSE L3 Support
^ permalink raw reply [flat|nested] 8+ messages in thread