Re: [patch] Real-Time Preemption, -RT-2.6.9-rc4-mm1-U8

[Scott Wood]

On Thu, Oct 21, 2004 at 10:10:17PM +0400, Eugeny S. Mints wrote:
> Scott Wood wrote:
> >If you keep it in priority order, then you're paying the O(n) cost
> >every time you acquire a lock.  If you keep it unordered and only
> >search it when you need to recalculate a task's priority after a lock
> >has been released (or priorities have been changed), you pay the cost
> >much less often.  Plus, the number of locks held by any given thread
> >should generally be very small.
> As to locks held by any given thread - it's not always true - take a 
> look at mm/filemap.c locks nesting map in comments.

I guess it depends on the definition of "very small" and "generally".
:-)

A nesting of 5 locks is pushing the limits of "very small", but it's
still no big deal to iterate over once in a while.

-Scott
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