Re: [PATCH] proc: revert to show stack information in/proc/{pid}/status

[Stefani Seibold]

Am Donnerstag, den 31.12.2009, 23:12 +0900 schrieb KOSAKI Motohiro:
> Commit d899bf7b (procfs: provide stack information for threads) introduced
> to show stack information in /proc/{pid}/status. But it cause large performance
> regression. Unfortunately /proc/{pid}/status is used ps command too and ps is
> one of most important component. Because both to take mmap_sem and page table walk
> are heavily operation.
> 

/proc/<pid>/status is IMHO not a performance relevant thing. The main
reason is to provide exact information about a running process.
 
> Thus, this patch revert it. Fortunately /proc/{pid}/task/{tid}/smaps
> provide almost same information. we can use it.
> 

Completely wrong. Where does smaps provides this kind of information?
Where is there the high water mark of the stack usage?

> Cc: Stefani Seibold <stefani@xxxxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxx>
> Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
> Cc: Alexey Dobriyan <adobriyan@xxxxxxxxx>
> Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
> Cc: Randy Dunlap <randy.dunlap@xxxxxxxxxx>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
> ---

Nak: Stefani Seibold <stefani@xxxxxxxxxxx>


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