The patch titled Subject: cpumask: introduce for_each_cpu_and_from() has been added to the -mm mm-nonmm-unstable branch. Its filename is cpumask-introduce-for_each_cpu_and_from.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/cpumask-introduce-for_each_cpu_and_from.patch This patch will later appear in the mm-nonmm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Yury Norov <yury.norov@xxxxxxxxx> Subject: cpumask: introduce for_each_cpu_and_from() Date: Thu, 28 Dec 2023 12:09:28 -0800 Patch series "lib/group_cpus: rework grp_spread_init_one() and make it O(1)", v4. grp_spread_init_one() implementation is sub-optimal because it traverses bitmaps from the beginning, instead of picking from the previous iteration. Fix it and use find_bit API where appropriate. While here, optimize cpumasks allocation and drop unneeded cpumask_empty() call. This patch (of 9): Similarly to for_each_cpu_and(), introduce a for_each_cpu_and_from(), which is handy when it's needed to traverse 2 cpumasks or bitmaps, starting from a given position. Link: https://lkml.kernel.org/r/20231228200936.2475595-1-yury.norov@xxxxxxxxx Link: https://lkml.kernel.org/r/20231228200936.2475595-2-yury.norov@xxxxxxxxx Signed-off-by: Yury Norov <yury.norov@xxxxxxxxx> Cc: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> Cc: Ming Lei <ming.lei@xxxxxxxxxx> Cc: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/cpumask.h | 11 +++++++++++ include/linux/find.h | 3 +++ 2 files changed, 14 insertions(+) --- a/include/linux/cpumask.h~cpumask-introduce-for_each_cpu_and_from +++ a/include/linux/cpumask.h @@ -333,6 +333,17 @@ unsigned int __pure cpumask_next_wrap(in for_each_and_bit(cpu, cpumask_bits(mask1), cpumask_bits(mask2), small_cpumask_bits) /** + * for_each_cpu_and_from - iterate over every cpu in both masks starting from a given cpu + * @cpu: the (optionally unsigned) integer iterator + * @mask1: the first cpumask pointer + * @mask2: the second cpumask pointer + * + * After the loop, cpu is >= nr_cpu_ids. + */ +#define for_each_cpu_and_from(cpu, mask1, mask2) \ + for_each_and_bit_from(cpu, cpumask_bits(mask1), cpumask_bits(mask2), small_cpumask_bits) + +/** * for_each_cpu_andnot - iterate over every cpu present in one mask, excluding * those present in another. * @cpu: the (optionally unsigned) integer iterator --- a/include/linux/find.h~cpumask-introduce-for_each_cpu_and_from +++ a/include/linux/find.h @@ -563,6 +563,9 @@ unsigned long find_next_bit_le(const voi (bit) = find_next_and_bit((addr1), (addr2), (size), (bit)), (bit) < (size);\ (bit)++) +#define for_each_and_bit_from(bit, addr1, addr2, size) \ + for (; (bit) = find_next_and_bit((addr1), (addr2), (size), (bit)), (bit) < (size); (bit)++) + #define for_each_andnot_bit(bit, addr1, addr2, size) \ for ((bit) = 0; \ (bit) = find_next_andnot_bit((addr1), (addr2), (size), (bit)), (bit) < (size);\ _ Patches currently in -mm which might be from yury.norov@xxxxxxxxx are cpumask-introduce-for_each_cpu_and_from.patch lib-group_cpus-optimize-inner-loop-in-grp_spread_init_one.patch lib-group_cpus-relax-atomicity-requirement-in-grp_spread_init_one.patch lib-group_cpus-optimize-outer-loop-in-grp_spread_init_one.patch lib-group_cpus-dont-zero-cpumasks-in-group_cpus_evenly-on-allocation.patch lib-group_cpus-drop-unneeded-cpumask_empty-call-in-__group_cpus_evenly.patch cpumask-define-cleanup-function-for-cpumasks.patch lib-group_cpus-rework-group_cpus_evenly.patch lib-group_cpus-simplify-group_cpus_evenly-for-more.patch