Messages in this thread |  | | Date | Tue, 18 Oct 2022 09:36:44 +0300 | Subject | Re: [PATCH v4 0/7] sched, net: NUMA-aware CPU spreading interface | From | Tariq Toukan <> |
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On 9/23/2022 4:25 PM, Valentin Schneider wrote: > Hi folks, > > Tariq pointed out in [1] that drivers allocating IRQ vectors would benefit > from having smarter NUMA-awareness (cpumask_local_spread() doesn't quite cut > it). > > The proposed interface involved an array of CPUs and a temporary cpumask, and > being my difficult self what I'm proposing here is an interface that doesn't > require any temporary storage other than some stack variables (at the cost of > one wild macro). > > Please note that this is based on top of Yury's bitmap-for-next [2] to leverage > his fancy new FIND_NEXT_BIT() macro. > > [1]: https://lore.kernel.org/all/20220728191203.4055-1-tariqt@nvidia.com/ > [2]: https://github.com/norov/linux.git/ -b bitmap-for-next > > A note on treewide use of for_each_cpu_andnot() > =============================================== > > I've used the below coccinelle script to find places that could be patched (I > couldn't figure out the valid syntax to patch from coccinelle itself): > > ,----- > @tmpandnot@ > expression tmpmask; > iterator for_each_cpu; > position p; > statement S; > @@ > cpumask_andnot(tmpmask, ...); > > ... > > ( > for_each_cpu@p(..., tmpmask, ...) > S > | > for_each_cpu@p(..., tmpmask, ...) > { > ... > } > ) > > @script:python depends on tmpandnot@ > p << tmpandnot.p; > @@ > coccilib.report.print_report(p[0], "andnot loop here") > '----- > > Which yields (against c40e8341e3b3): > > .//arch/powerpc/kernel/smp.c:1587:1-13: andnot loop here > .//arch/powerpc/kernel/smp.c:1530:1-13: andnot loop here > .//arch/powerpc/kernel/smp.c:1440:1-13: andnot loop here > .//arch/powerpc/platforms/powernv/subcore.c:306:2-14: andnot loop here > .//arch/x86/kernel/apic/x2apic_cluster.c:62:1-13: andnot loop here > .//drivers/acpi/acpi_pad.c:110:1-13: andnot loop here > .//drivers/cpufreq/armada-8k-cpufreq.c:148:1-13: andnot loop here > .//drivers/cpufreq/powernv-cpufreq.c:931:1-13: andnot loop here > .//drivers/net/ethernet/sfc/efx_channels.c:73:1-13: andnot loop here > .//drivers/net/ethernet/sfc/siena/efx_channels.c:73:1-13: andnot loop here > .//kernel/sched/core.c:345:1-13: andnot loop here > .//kernel/sched/core.c:366:1-13: andnot loop here > .//net/core/dev.c:3058:1-13: andnot loop here > > A lot of those are actually of the shape > > for_each_cpu(cpu, mask) { > ... > cpumask_andnot(mask, ...); > } > > I think *some* of the powerpc ones would be a match for for_each_cpu_andnot(), > but I decided to just stick to the one obvious one in __sched_core_flip(). > > Revisions > ========= > > v3 -> v4 > ++++++++ > > o Rebased on top of Yury's bitmap-for-next > o Added Tariq's mlx5e patch > o Made sched_numa_hop_mask() return cpu_online_mask for the NUMA_NO_NODE && > hops=0 case > > v2 -> v3 > ++++++++ > > o Added for_each_cpu_and() and for_each_cpu_andnot() tests (Yury) > o New patches to fix issues raised by running the above > > o New patch to use for_each_cpu_andnot() in sched/core.c (Yury) > > v1 -> v2 > ++++++++ > > o Split _find_next_bit() @invert into @invert1 and @invert2 (Yury) > o Rebase onto v6.0-rc1 > > Cheers, > Valentin >
Hi,
What's the status of this? Do we have agreement on the changes needed for the next respin?
Regards, Tariq
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