Messages in this thread Patch in this message |  | | From | Yury Norov <> | Subject | [PATCH 3/7] cpumask: switch for_each_cpu{,_not} to use for_each_bit() | Date | Mon, 19 Sep 2022 14:05:55 -0700 |
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The difference between for_each_cpu() and for_each_set_bit() is that the latter uses cpumask_next() instead of find_next_bit(), and so calls cpumask_check().
This check is useless because the iterator value is not provided by user. It generates false-positives for the very last iteration of for_each_cpu().
Signed-off-by: Yury Norov <yury.norov@gmail.com> --- include/linux/cpumask.h | 12 +++--------- include/linux/find.h | 5 +++++ 2 files changed, 8 insertions(+), 9 deletions(-)
diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h index a1cd4eb1a3d6..3a9566f1373a 100644 --- a/include/linux/cpumask.h +++ b/include/linux/cpumask.h @@ -243,9 +243,7 @@ unsigned int cpumask_next_and(int n, const struct cpumask *src1p, * After the loop, cpu is >= nr_cpu_ids. */ #define for_each_cpu(cpu, mask) \ - for ((cpu) = -1; \ - (cpu) = cpumask_next((cpu), (mask)), \ - (cpu) < nr_cpu_ids;) + for_each_set_bit(cpu, cpumask_bits(mask), nr_cpumask_bits) /** * for_each_cpu_not - iterate over every cpu in a complemented mask @@ -255,9 +253,7 @@ unsigned int cpumask_next_and(int n, const struct cpumask *src1p, * After the loop, cpu is >= nr_cpu_ids. */ #define for_each_cpu_not(cpu, mask) \ - for ((cpu) = -1; \ - (cpu) = cpumask_next_zero((cpu), (mask)), \ - (cpu) < nr_cpu_ids;) + for_each_clear_bit(cpu, cpumask_bits(mask), nr_cpumask_bits) #if NR_CPUS == 1 static inline @@ -310,9 +306,7 @@ unsigned int __pure cpumask_next_wrap(int n, const struct cpumask *mask, int sta * After the loop, cpu is >= nr_cpu_ids. */ #define for_each_cpu_and(cpu, mask1, mask2) \ - for ((cpu) = -1; \ - (cpu) = cpumask_next_and((cpu), (mask1), (mask2)), \ - (cpu) < nr_cpu_ids;) + for_each_and_bit(cpu, cpumask_bits(mask1), cpumask_bits(mask2), nr_cpumask_bits) /** * cpumask_any_but - return a "random" in a cpumask, but not this one. diff --git a/include/linux/find.h b/include/linux/find.h index b100944daba0..128615a3f93e 100644 --- a/include/linux/find.h +++ b/include/linux/find.h @@ -390,6 +390,11 @@ unsigned long find_next_bit_le(const void *addr, unsigned (bit) < (size); \ (bit) = find_next_bit((addr), (size), (bit) + 1)) +#define for_each_and_bit(bit, addr1, addr2, size) \ + for ((bit) = find_next_and_bit((addr1), (addr2), (size), 0); \ + (bit) < (size); \ + (bit) = find_next_and_bit((addr1), (addr2), (size), (bit) + 1)) + /* same as for_each_set_bit() but use bit as value to start with */ #define for_each_set_bit_from(bit, addr, size) \ for ((bit) = find_next_bit((addr), (size), (bit)); \ -- 2.34.1
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