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Code Issues Releases Wiki Activity

powerpc: remove cpu_online_cores_map function

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This function builds the cores online map with on-stack cpumasks which
can cause high stack usage with large NR_CPUS.

It is not used in any performance sensitive paths, so instead just check
for first thread sibling.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Tested-by: Sachin Sant <sachinp@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211105035042.1398309-1-npiggin@gmail.com
This commit is contained in:
Nicholas Piggin 2021-11-05 13:50:41 +10:00 committed by Michael Ellerman
parent af3fdce4ab
commit b350111bf7
3 changed files with 8 additions and 41 deletions
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33
arch/powerpc/include/asm/cputhreads.h
View file

@ -32,44 +32,11 @@ extern cpumask_t threads_core_mask;
#define threads_core_mask (*get_cpu_mask(0))
#endif
/* cpu_thread_mask_to_cores - Return a cpumask of one per cores
* hit by the argument
*
* @threads: a cpumask of online threads
*
* This function returns a cpumask which will have one online cpu's
* bit set for each core that has at least one thread set in the argument.
*
* This can typically be used for things like IPI for tlb invalidations
* since those need to be done only once per core/TLB
*/
static inline cpumask_t cpu_thread_mask_to_cores(const struct cpumask *threads)
{
cpumask_t tmp, res;
int i, cpu;
cpumask_clear(&res);
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);
if (cpu < nr_cpu_ids)
cpumask_set_cpu(cpu, &res);
}
}
return res;
}
static inline int cpu_nr_cores(void)
{
return nr_cpu_ids >> threads_shift;
}
static inline cpumask_t cpu_online_cores_map(void)
{
return cpu_thread_mask_to_cores(cpu_online_mask);
}
#ifdef CONFIG_SMP
int cpu_core_index_of_thread(int cpu);
int cpu_first_thread_of_core(int core);

10
arch/powerpc/platforms/powernv/idle.c
View file

@ -146,9 +146,13 @@ EXPORT_SYMBOL_GPL(pnv_get_supported_cpuidle_states);
static void pnv_fastsleep_workaround_apply(void *info)
{
int cpu = smp_processor_id();
int rc;
int *err = info;
if (cpu_first_thread_sibling(cpu) != cpu)
return;
rc = opal_config_cpu_idle_state(OPAL_CONFIG_IDLE_FASTSLEEP,
OPAL_CONFIG_IDLE_APPLY);
if (rc)
@ -175,7 +179,6 @@ static ssize_t store_fastsleep_workaround_applyonce(struct device *dev,
struct device_attribute *attr, const char *buf,
size_t count)
{
cpumask_t primary_thread_mask;
int err;
u8 val;
@ -200,10 +203,7 @@ static ssize_t store_fastsleep_workaround_applyonce(struct device *dev,
power7_fastsleep_workaround_exit = false;
cpus_read_lock();
primary_thread_mask = cpu_online_cores_map();
on_each_cpu_mask(&primary_thread_mask,
pnv_fastsleep_workaround_apply,
&err, 1);
on_each_cpu(pnv_fastsleep_workaround_apply, &err, 1);
cpus_read_unlock();
if (err) {
pr_err("fastsleep_workaround_applyonce change failed while running pnv_fastsleep_workaround_apply");

6
arch/powerpc/platforms/powernv/opal-imc.c
View file

@ -200,13 +200,13 @@ static void disable_nest_pmu_counters(void)
static void disable_core_pmu_counters(void)
{
cpumask_t cores_map;
int cpu, rc;
cpus_read_lock();
/* Disable the IMC Core functions */
cores_map = cpu_online_cores_map();
for_each_cpu(cpu, &cores_map) {
for_each_online_cpu(cpu) {
if (cpu_first_thread_sibling(cpu) != cpu)
continue;
rc = opal_imc_counters_stop(OPAL_IMC_COUNTERS_CORE,
get_hard_smp_processor_id(cpu));
if (rc)