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Date: Sat, 31 Jan 2009 11:03:07 -0800 (PST)
From: Davide Libenzi <davidel@xmailserver.org>
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To: Alan Cox <alan@lxorguk.ukuu.org.uk>
cc: Ingo Molnar <mingo@elte.hu>,
       Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
       Andrew Morton <akpm@linux-foundation.org>,
       Linus Torvalds <torvalds@linux-foundation.org>,
       David Miller <davem@davemloft.net>
Subject: Re: [patch 3/7] epoll keyed wakeups - introduce key-aware wakeup
 macros
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On Sat, 31 Jan 2009, Alan Cox wrote:

> > One minor worry i have: these wakeup calls are _very_ common in the 
> > kernel, and this patch adds an extra parameter to it that is unused (NULL) 
> > in 99% of the cases.
> 
> And in most of the cases it is used is constant for the waitqueue anyway
> or appears to be (eg the tty patch). I don't think we should be stacking
> extra parameters on all those zillions of calls made all over the kernel
> and for no purpose - so the existing wakeup functions should stay as is
> for performance as well as for size (which due to cache pressure is
> performance).

Besides for that, did the TTY patch look sane to you? Did I get all the 
wakeup points? TTY code always gave me the willies :)


- Davide