> A bisection doesn't require any special skills, but may give busy > maintainers a single change to eyeball vs the entire lot.
They have been couple of merges which makes git revert difficult but I will try to produce patch files for kernel/sched directory only with git diff v4.4-rc4..fe19159 -- sched and let you the outcome. On Sat, Dec 12, 2015 at 8:04 AM, Mike Galbraith <umgwanakikb...@gmail.com> wrote: > (it's always a good idea to CC subsystem maintainers when reporting) > > On Fri, 2015-12-11 at 15:17 +0100, Jirka Hladky wrote: >> Hello, >> >> we are doing performance testing of the new kernel scheduler (commit >> 53528695ff6d8b77011bc818407c13e30914a946). In most cases we see >> performance improvements compared to 4.3 kernel with the exception of >> stream benchmark when running on 4 NUMA node server. >> >> When we run 4 stream benchmark processes on 4 NUMA node server and we >> compare the total performance we see drop about 24% compared to 4.3 >> kernel. This is caused by the fact that 2 stream benchmarks are >> running on the same NUMA node while 1 NUMA node does not run any >> stream benchmark. With kernel 4.3, load is distributed evenly among >> all 4 NUMA nodes. When two stream benchmarks are running on the same >> NUMA node then the runtime is almost twice as long compared to one >> stream bench running on one NUMA node. See log files [1] bellow. >> >> Please see the graph comparing stream benchmark results between >> kernel >> 4.3 and 4.4rc4 (for legend see [2] bellow). >> https://jhladky.fedorapeople.org/sched_stream_kernel_4.3vs4.4rc4/Stre >> am_benchmark_on_4_NUMA_node_server_4.3vs4.4rc4_kernel.png >> >> Could you please help us to identify the root cause of this >> regression? We don't have the skills to fix the problem ourselves but >> we will be more than happy to test any proposed patch for this issue. > > A bisection doesn't require any special skills, but may give busy > maintainers a single change to eyeball vs the entire lot. > > -Mike -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
