Re: [RFC][PATCH 0/5] Signal scalability series

From: Tejun Heo
Date: Fri Sep 30 2011 - 19:56:36 EST


Hello,

On Fri, Sep 30, 2011 at 09:00:23PM +0100, Matt Fleming wrote:
> On Fri, 2011-09-30 at 18:52 +0200, Oleg Nesterov wrote:
> Well, sighand->siglock is seriously overused. It protects so much and I
> think it's pretty confusing. It took me long enough to figure out how
> many locks were really needed. But that's beside the point, having a
> single lock doesn't scale at all, and that's what this series is about.

But scalability for what? What are the use cases here? Do we care
enough about benefits to those use cases to accept the increased
complexity? Having locks with broad coverage isn't necessarily evil.
If things are simpler that way and the protected paths aren't that
hot, who cares? If splitting the locking makes things simpler, sure
but that doesn't look like the case here, so we need pretty strong
rationale to justify the added complexity.

Thank you.

--
tejun
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