Re: [patch 1/3] move WARN_ON() out of line

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From: Arjan van de Ven
Date: Thursday, January 3, 2008 - 9:22 am

Ingo Molnar wrote:

I can see that; I'll play with that


the asm generated for this is 2 movl instructions for immediate to register.
Doing fancy tricks ... it may well end up bigger and gain nothing.

function calls are *CHEAP*.

passing the condition is actually near free (remember we have regparm!), it's likely to be
in a register already anyway.

Doing the test inline makes stuff bigger, and also spreads the branch prediction pain around
rather than having one nicely predictable place...


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Messages in current thread:
[patch 1/3] move WARN_ON() out of line, Arjan van de Ven, (Wed Jan 2, 5:56 pm)
Re: [patch 1/3] move WARN_ON() out of line, Olof Johansson, (Wed Jan 2, 9:58 pm)
Re: [patch 1/3] move WARN_ON() out of line, Ingo Molnar, (Thu Jan 3, 2:25 am)
Re: [patch 1/3] move WARN_ON() out of line, Arjan van de Ven, (Thu Jan 3, 9:22 am)
Re: [patch 1/3] move WARN_ON() out of line, Arjan van de Ven, (Thu Jan 3, 2:03 pm)
Re: [patch 1/3] move WARN_ON() out of line, Arjan van de Ven, (Thu Jan 3, 2:06 pm)
Re: [patch 1/3] move WARN_ON() out of line, Herbert Xu, (Fri Jan 4, 7:35 pm)
Re: [patch 1/3] move WARN_ON() out of line, Jeremy Fitzhardinge, (Fri Jan 4, 11:41 pm)
Re: [patch 1/3] move WARN_ON() out of line, Jeremy Fitzhardinge, (Fri Jan 4, 11:42 pm)
Re: [patch 1/3] move WARN_ON() out of line, Arjan van de Ven, (Sat Jan 5, 11:01 am)
Re: [patch 1/3] move WARN_ON() out of line, Arjan van de Ven, (Sat Jan 5, 11:08 am)
Re: [patch 1/3] move WARN_ON() out of line, Arjan van de Ven, (Sat Jan 5, 11:33 am)
Re: [patch 1/3] move WARN_ON() out of line, Arjan van de Ven, (Sat Jan 5, 11:37 am)
Re: [patch 1/3] move WARN_ON() out of line, Jeremy Fitzhardinge, (Sat Jan 5, 11:45 am)
Re: [patch 1/3] move WARN_ON() out of line, Arjan van de Ven, (Sat Jan 5, 1:02 pm)