cpumask_first() is a more effective analogue of 'next' version if n == -1 (which means start == 0). This patch replaces 'next' with 'first' where things look trivial.
There's no cpumask_first_zero() function, so create it.
Signed-off-by: Yury Norov yury.norov@gmail.com Tested-by: Wolfram Sang wsa+renesas@sang-engineering.com --- arch/powerpc/include/asm/cputhreads.h | 2 +- block/blk-mq.c | 2 +- drivers/net/virtio_net.c | 2 +- drivers/soc/fsl/qbman/bman_portal.c | 2 +- drivers/soc/fsl/qbman/qman_portal.c | 2 +- include/linux/cpumask.h | 16 ++++++++++++++++ kernel/time/clocksource.c | 4 ++-- 7 files changed, 23 insertions(+), 7 deletions(-)
diff --git a/arch/powerpc/include/asm/cputhreads.h b/arch/powerpc/include/asm/cputhreads.h index b167186aaee4..44286df21d2a 100644 --- a/arch/powerpc/include/asm/cputhreads.h +++ b/arch/powerpc/include/asm/cputhreads.h @@ -52,7 +52,7 @@ static inline cpumask_t cpu_thread_mask_to_cores(const struct cpumask *threads) for (i = 0; i < NR_CPUS; i += threads_per_core) { cpumask_shift_left(&tmp, &threads_core_mask, i); if (cpumask_intersects(threads, &tmp)) { - cpu = cpumask_next_and(-1, &tmp, cpu_online_mask); + cpu = cpumask_first_and(&tmp, cpu_online_mask); if (cpu < nr_cpu_ids) cpumask_set_cpu(cpu, &res); } diff --git a/block/blk-mq.c b/block/blk-mq.c index 21bf4c3f0825..5b28d204d7bc 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2538,7 +2538,7 @@ static bool blk_mq_hctx_has_requests(struct blk_mq_hw_ctx *hctx) static inline bool blk_mq_last_cpu_in_hctx(unsigned int cpu, struct blk_mq_hw_ctx *hctx) { - if (cpumask_next_and(-1, hctx->cpumask, cpu_online_mask) != cpu) + if (cpumask_first_and(hctx->cpumask, cpu_online_mask) != cpu) return false; if (cpumask_next_and(cpu, hctx->cpumask, cpu_online_mask) < nr_cpu_ids) return false; diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 2ed49884565f..986cb7a73a92 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -2089,7 +2089,7 @@ static void virtnet_set_affinity(struct virtnet_info *vi) stragglers = num_cpu >= vi->curr_queue_pairs ? num_cpu % vi->curr_queue_pairs : 0; - cpu = cpumask_next(-1, cpu_online_mask); + cpu = cpumask_first(cpu_online_mask);
for (i = 0; i < vi->curr_queue_pairs; i++) { group_size = stride + (i < stragglers ? 1 : 0); diff --git a/drivers/soc/fsl/qbman/bman_portal.c b/drivers/soc/fsl/qbman/bman_portal.c index acda8a5637c5..4d7b9caee1c4 100644 --- a/drivers/soc/fsl/qbman/bman_portal.c +++ b/drivers/soc/fsl/qbman/bman_portal.c @@ -155,7 +155,7 @@ static int bman_portal_probe(struct platform_device *pdev) }
spin_lock(&bman_lock); - cpu = cpumask_next_zero(-1, &portal_cpus); + cpu = cpumask_first_zero(&portal_cpus); if (cpu >= nr_cpu_ids) { __bman_portals_probed = 1; /* unassigned portal, skip init */ diff --git a/drivers/soc/fsl/qbman/qman_portal.c b/drivers/soc/fsl/qbman/qman_portal.c index 96f74a1dc603..e23b60618c1a 100644 --- a/drivers/soc/fsl/qbman/qman_portal.c +++ b/drivers/soc/fsl/qbman/qman_portal.c @@ -248,7 +248,7 @@ static int qman_portal_probe(struct platform_device *pdev) pcfg->pools = qm_get_pools_sdqcr();
spin_lock(&qman_lock); - cpu = cpumask_next_zero(-1, &portal_cpus); + cpu = cpumask_first_zero(&portal_cpus); if (cpu >= nr_cpu_ids) { __qman_portals_probed = 1; /* unassigned portal, skip init */ diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h index c4e1b9ea0ba4..64dae70d31f5 100644 --- a/include/linux/cpumask.h +++ b/include/linux/cpumask.h @@ -123,6 +123,11 @@ static inline unsigned int cpumask_first(const struct cpumask *srcp) return 0; }
+static inline unsigned int cpumask_first_zero(const struct cpumask *srcp) +{ + return 0; +} + static inline unsigned int cpumask_first_and(const struct cpumask *srcp1, const struct cpumask *srcp2) { @@ -201,6 +206,17 @@ static inline unsigned int cpumask_first(const struct cpumask *srcp) return find_first_bit(cpumask_bits(srcp), nr_cpumask_bits); }
+/** + * cpumask_first_zero - get the first unset cpu in a cpumask + * @srcp: the cpumask pointer + * + * Returns >= nr_cpu_ids if all cpus are set. + */ +static inline unsigned int cpumask_first_zero(const struct cpumask *srcp) +{ + return find_first_zero_bit(cpumask_bits(srcp), nr_cpumask_bits); +} + /** * cpumask_first_and - return the first cpu from *srcp1 & *srcp2 * @src1p: the first input diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index b038b81f8d32..2f170383b00a 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -262,7 +262,7 @@ static void clocksource_verify_choose_cpus(void) return;
/* Make sure to select at least one CPU other than the current CPU. */ - cpu = cpumask_next(-1, cpu_online_mask); + cpu = cpumask_first(cpu_online_mask); if (cpu == smp_processor_id()) cpu = cpumask_next(cpu, cpu_online_mask); if (WARN_ON_ONCE(cpu >= nr_cpu_ids)) @@ -284,7 +284,7 @@ static void clocksource_verify_choose_cpus(void) cpu = prandom_u32() % nr_cpu_ids; cpu = cpumask_next(cpu - 1, cpu_online_mask); if (cpu >= nr_cpu_ids) - cpu = cpumask_next(-1, cpu_online_mask); + cpu = cpumask_first(cpu_online_mask); if (!WARN_ON_ONCE(cpu >= nr_cpu_ids)) cpumask_set_cpu(cpu, &cpus_chosen); }