On Wed, Jun 28, 2017 at 10:16 PM, Luc Van Oostenryck <luc.vanoostenryck@xxxxxxxxx> wrote: > > What can be win with these small changes is quite appreciable: > about 30% with some gain in speed too (but this are harder to > put numbers on it, 5% or a bit more seems quite common for > big files). I am curious about the performance difference against the full kernel source check with sparse. I have some benchmark script build for that with linux "allmodconfig". My test environment will only do sparse portion of the checking and save the result into files. The makefile is non-recursive so it is much faster than running sparse from the kernel build. A kernel no change incremental build take about 2m10s. On my non-recursive makefile for sparse it is only 4 seconds. So the overhead of make itself is very light. Any way, the two run of normal build of RC3: $ time make -f $PWD/linux-checker.make -j12 -C ../linux name=master real 2m31.778s user 18m18.019s sys 8m19.468s real 2m29.668s user 18m12.991s sys 8m12.728s two run with LIST_NODE_NR = 13 version of sparse real 2m27.166s user 18m3.866s sys 7m51.140s real 2m28.089s user 18m5.966s sys 7m49.956s So it is barely able to register a real world difference, consider the run to run variance is about 2 second as well. The number for the pure sparse run is about 1.3% difference on the full kernel allmodconfig build. Chris -- To unsubscribe from this list: send the line "unsubscribe linux-sparse" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
