Messages in this thread | | | Date | Wed, 18 Sep 2002 23:15:47 +0200 | From | Andries Brouwer <> | Subject | Re: [patch] lockless, scalable get_pid(), for_each_process() elimination, 2.5.35-BK |
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On Wed, Sep 18, 2002 at 01:29:14PM -0700, William Lee Irwin III wrote:
> I've seen no change in behavior with large PID_MAX.
Of course not. But people keep blaming the wrong routine. I have said it a thousand times - nothing is wrong with get_pid().
Now proc_pid_readdir() takes a million times as long, so it would be much more reasonable if people talked about it instead. With 20000 processes it will visit 10^7 process structs for one ps.
> It doesn't sound like you read the patch at all.
I looked at it and searched for base.c but didnt find it, so concluded that the real problem was not addressed.
> > In procfs we have a very quadratic algorithm in proc_pid_readdir()/ > > get_pid_list(). Not a potential hiccup after 2^30 processes that some > > may want to smoothe, but every single "ls /proc" or "ps". > > What shall we do with /proc for all these people with 10^5 processes? > > Andries > > That is actually one of the easiest ways to take out one of my machines > while it's running 10K or so tasks, mentioned a bit ago in this thread.
OK. So we now agree.
But it looks like your patch doesnt change this? Or did I overlook sth?
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