Messages in this thread |  | | Date | Wed, 26 Sep 2001 11:24:44 -0700 (PDT) | From | Linus Torvalds <> | Subject | Re: Locking comment on shrink_caches() |
| |
On Wed, 26 Sep 2001, Dave Jones wrote: > On Wed, 26 Sep 2001, Alan Cox wrote: > > > VIA Cyrix CIII (original generation 0.18u) > > > > nothing: 28 cycles > > locked add: 29 cycles > > cpuid: 72 cycles > > Interesting. From a newer C3.. > > nothing: 30 cycles > locked add: 31 cycles > cpuid: 79 cycles > > Only slightly worse, but I'd not expected this.
That difference can easily be explained by the compiler and options.
You should use "gcc -O2" at least, in order to avoid having gcc do unnecessary spills to memory in between the timings. And there may be some versions of gcc that en dup spilling even then.
Linus
- 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/
|  |