Messages in this thread | | | Date | Mon, 29 Jul 2002 10:01:26 +0200 (CEST) | From | Roman Zippel <> | Subject | Re: Patch: linux-2.5.29 __downgrade_write() for CONFIG_RWSEM_GENERIC_SPINLOCK |
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Hi,
On Mon, 29 Jul 2002, David Howells wrote:
> > You don't really need that extra argument, testing sem->activity should do > > the same job. > > If you exchange the wakewrite (or sem->activity) test and the > > waiter->flags you can fold it into the next test (this means all the extra > > work would only be done, if we have a writer waiting at the top). > > The reason for doing it this way is that it allows the compiler to discard > parts of the function when inlining it since the value is set at compile time > rather than being worked out at runtime. The value itself should be > disappeared entirely by the compiler.
Did you look at the code? gcc should be able to optimize that itself.
bye, Roman
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