Messages in this thread | | | Subject | Re: [PATCH] no need to check for NULL before calling kfree() -fs/ext2/ | Date | Sun, 27 Mar 2005 21:20:14 -0400 | From | Horst von Brand <> |
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Dave Jones <davej@redhat.com> said: > On Sun, Mar 27, 2005 at 05:12:58PM +0200, Jan Engelhardt wrote: > > > Well, kfree inlined was already mentioned but forgotten again. > > What if this was used: > > > > inline static void kfree_WRAP(void *addr) { > > if(likely(addr != NULL)) { > > kfree_real(addr); > > } > > return; > > } > > > > And remove the NULL-test in kfree_real()? Then we would have:
> Am I the only person who is completely fascinated by the > effort being spent here micro-optimising something thats > almost never in a path that needs optimising ? > I'd be amazed if any of this masturbation showed the tiniest > blip on a real workload, or even on a benchmark other than > one crafted specifically to test kfree in a loop.
Right.
> That each occurance of this 'optimisation' also saves a handful > of bytes in generated code is it's only real benefit afaics.
No. It clears up the calls to kfree() a bit too in the source. Not really important, sure. . > Even then, if a functions cache performance is better off because > we trimmed a few bytes from the tail of a function, I'd be > completely amazed. > > I guess April 1st came early this year.
Got (at) you! ;-) -- Dr. Horst H. von Brand User #22616 counter.li.org Departamento de Informatica Fono: +56 32 654431 Universidad Tecnica Federico Santa Maria +56 32 654239 Casilla 110-V, Valparaiso, Chile Fax: +56 32 797513 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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