"Michael S. Tsirkin" <mst@xxxxxxxxxx> writes: > On Wed, Mar 06, 2013 at 04:22:09PM +1100, Rusty Russell wrote: >> We use inline and get gcc to do the right thing inlining the >> "indirect" traversal functions. This also means we don't need to >> clean the sgs. >> >> for i in `seq 50`; do /usr/bin/time -f 'Wall time:%e' ./vringh_test --indirect --eventidx --parallel --fast-vringh; done 2>&1 | stats --trim-outliers: >> >> Before: >> Using CPUS 0 and 3 >> Guest: notified 0, pinged 39014-39063(39062) >> Host: notified 39014-39063(39062), pinged 0 >> Wall time:1.900000-2.350000(1.921875) >> >> After: >> Using CPUS 0 and 3 >> Guest: notified 0, pinged 39062-39063(39063) >> Host: notified 39062-39063(39063), pinged 0 >> Wall time:1.760000-2.220000(1.789167) >> >> Signed-off-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx> > > It's pretty cool that gcc is able to optimize it like this. > Which gcc version did you use here? Gcc has done this for quite a while now... I reported a bug about it in 2008: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35728 This was i686-linux-gnu-gcc-4.7 (Ubuntu/Linaro 4.7.2-2ubuntu1) 4.7.2. Cheers, Rusty. _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
