Messages in this thread | | | Date | Sun, 23 Feb 2003 19:49:41 +0100 (CET) | From | Ingo Molnar <> | Subject | Re: [patch] procfs/procps threading performance speedup, 2.5.62 |
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On 22 Feb 2003, Albert Cahalan wrote:
> > architecture-wise there is a difference, and i'd be > > the last one arguing against a tree-based approach to > > thread groups. It's much easier to find threads belonging > > to a single 'process' via /proc this way - although no > > functionality in procps has or requires such a feature currently. > > Nope, the /proc/123/threads/246/stat approach is required. Without this, > procps is forced to read _all_ tasks to group threads together. This is > slow, prone to race conditions, more vulnerable to kernel bugs, and a > memory hog.
actually, what you mention does not happen in practice. We coded it up and it works, and with tons of threads around it performs a few orders of magnitudes faster than any other stuff available so far. So the question here is 'only' interface/approach cleanliness, not actual performance difference. Sure, we could shave off another millisec or two, but the performance problems are off the radar already.
> Note that the recent /proc/*/wchan addition was botched.
(fyi, i have nothing to do with that change, so spare your insults for someone else.)
> (next time, discuss such changes with an experienced procps developer > first)
(given that this whole area was left alone in a state like this for years i'm not quite sure how you can still sit so high on your horse.)
Ingo
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