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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel…
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…/git/tj/percpu

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
  sched: move rq_weight data array out of .percpu
  percpu: allow pcpu_alloc() to be called with IRQs off
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@torvalds
torvalds committed Oct 29, 2009
2 parents 9532fae + 4a6cc4b commit 8633322
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Showing 2 changed files with 28 additions and 24 deletions.
22 changes: 11 additions & 11 deletions kernel/sched.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1564,11 +1564,7 @@ static unsigned long cpu_avg_load_per_task(int cpu)

#ifdef CONFIG_FAIR_GROUP_SCHED

struct update_shares_data {
unsigned long rq_weight[NR_CPUS];
};

static DEFINE_PER_CPU(struct update_shares_data, update_shares_data);
static __read_mostly unsigned long *update_shares_data;

static void __set_se_shares(struct sched_entity *se, unsigned long shares);

Expand All @@ -1578,12 +1574,12 @@ static void __set_se_shares(struct sched_entity *se, unsigned long shares);
static void update_group_shares_cpu(struct task_group *tg, int cpu,
unsigned long sd_shares,
unsigned long sd_rq_weight,
struct update_shares_data *usd)
unsigned long *usd_rq_weight)
{
unsigned long shares, rq_weight;
int boost = 0;

rq_weight = usd->rq_weight[cpu];
rq_weight = usd_rq_weight[cpu];
if (!rq_weight) {
boost = 1;
rq_weight = NICE_0_LOAD;
Expand Down Expand Up @@ -1618,7 +1614,7 @@ static void update_group_shares_cpu(struct task_group *tg, int cpu,
static int tg_shares_up(struct task_group *tg, void *data)
{
unsigned long weight, rq_weight = 0, shares = 0;
struct update_shares_data *usd;
unsigned long *usd_rq_weight;
struct sched_domain *sd = data;
unsigned long flags;
int i;
Expand All @@ -1627,11 +1623,11 @@ static int tg_shares_up(struct task_group *tg, void *data)
return 0;

local_irq_save(flags);
usd = &__get_cpu_var(update_shares_data);
usd_rq_weight = per_cpu_ptr(update_shares_data, smp_processor_id());

for_each_cpu(i, sched_domain_span(sd)) {
weight = tg->cfs_rq[i]->load.weight;
usd->rq_weight[i] = weight;
usd_rq_weight[i] = weight;

/*
* If there are currently no tasks on the cpu pretend there
Expand All @@ -1652,7 +1648,7 @@ static int tg_shares_up(struct task_group *tg, void *data)
shares = tg->shares;

for_each_cpu(i, sched_domain_span(sd))
update_group_shares_cpu(tg, i, shares, rq_weight, usd);
update_group_shares_cpu(tg, i, shares, rq_weight, usd_rq_weight);

local_irq_restore(flags);

Expand Down Expand Up @@ -9407,6 +9403,10 @@ void __init sched_init(void)
#endif /* CONFIG_USER_SCHED */
#endif /* CONFIG_GROUP_SCHED */

#if defined CONFIG_FAIR_GROUP_SCHED && defined CONFIG_SMP
update_shares_data = __alloc_percpu(nr_cpu_ids * sizeof(unsigned long),
__alignof__(unsigned long));
#endif
for_each_possible_cpu(i) {
struct rq *rq;

Expand Down
30 changes: 17 additions & 13 deletions mm/percpu.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -153,7 +153,10 @@ static int pcpu_reserved_chunk_limit;
*
* During allocation, pcpu_alloc_mutex is kept locked all the time and
* pcpu_lock is grabbed and released as necessary. All actual memory
* allocations are done using GFP_KERNEL with pcpu_lock released.
* allocations are done using GFP_KERNEL with pcpu_lock released. In
* general, percpu memory can't be allocated with irq off but
* irqsave/restore are still used in alloc path so that it can be used
* from early init path - sched_init() specifically.
*
* Free path accesses and alters only the index data structures, so it
* can be safely called from atomic context. When memory needs to be
Expand Down Expand Up @@ -366,7 +369,7 @@ static struct pcpu_chunk *pcpu_chunk_addr_search(void *addr)
* RETURNS:
* 0 if noop, 1 if successfully extended, -errno on failure.
*/
static int pcpu_extend_area_map(struct pcpu_chunk *chunk)
static int pcpu_extend_area_map(struct pcpu_chunk *chunk, unsigned long *flags)
{
int new_alloc;
int *new;
Expand All @@ -376,15 +379,15 @@ static int pcpu_extend_area_map(struct pcpu_chunk *chunk)
if (chunk->map_alloc >= chunk->map_used + 2)
return 0;

spin_unlock_irq(&pcpu_lock);
spin_unlock_irqrestore(&pcpu_lock, *flags);

new_alloc = PCPU_DFL_MAP_ALLOC;
while (new_alloc < chunk->map_used + 2)
new_alloc *= 2;

new = pcpu_mem_alloc(new_alloc * sizeof(new[0]));
if (!new) {
spin_lock_irq(&pcpu_lock);
spin_lock_irqsave(&pcpu_lock, *flags);
return -ENOMEM;
}

Expand All @@ -393,7 +396,7 @@ static int pcpu_extend_area_map(struct pcpu_chunk *chunk)
* could have happened inbetween, so map_used couldn't have
* grown.
*/
spin_lock_irq(&pcpu_lock);
spin_lock_irqsave(&pcpu_lock, *flags);
BUG_ON(new_alloc < chunk->map_used + 2);

size = chunk->map_alloc * sizeof(chunk->map[0]);
Expand Down Expand Up @@ -1047,6 +1050,7 @@ static void *pcpu_alloc(size_t size, size_t align, bool reserved)
struct pcpu_chunk *chunk;
const char *err;
int slot, off;
unsigned long flags;

if (unlikely(!size || size > PCPU_MIN_UNIT_SIZE || align > PAGE_SIZE)) {
WARN(true, "illegal size (%zu) or align (%zu) for "
Expand All @@ -1055,13 +1059,13 @@ static void *pcpu_alloc(size_t size, size_t align, bool reserved)
}

mutex_lock(&pcpu_alloc_mutex);
spin_lock_irq(&pcpu_lock);
spin_lock_irqsave(&pcpu_lock, flags);

/* serve reserved allocations from the reserved chunk if available */
if (reserved && pcpu_reserved_chunk) {
chunk = pcpu_reserved_chunk;
if (size > chunk->contig_hint ||
pcpu_extend_area_map(chunk) < 0) {
pcpu_extend_area_map(chunk, &flags) < 0) {
err = "failed to extend area map of reserved chunk";
goto fail_unlock;
}
Expand All @@ -1079,7 +1083,7 @@ static void *pcpu_alloc(size_t size, size_t align, bool reserved)
if (size > chunk->contig_hint)
continue;

switch (pcpu_extend_area_map(chunk)) {
switch (pcpu_extend_area_map(chunk, &flags)) {
case 0:
break;
case 1:
Expand All @@ -1096,24 +1100,24 @@ static void *pcpu_alloc(size_t size, size_t align, bool reserved)
}

/* hmmm... no space left, create a new chunk */
spin_unlock_irq(&pcpu_lock);
spin_unlock_irqrestore(&pcpu_lock, flags);

chunk = alloc_pcpu_chunk();
if (!chunk) {
err = "failed to allocate new chunk";
goto fail_unlock_mutex;
}

spin_lock_irq(&pcpu_lock);
spin_lock_irqsave(&pcpu_lock, flags);
pcpu_chunk_relocate(chunk, -1);
goto restart;

area_found:
spin_unlock_irq(&pcpu_lock);
spin_unlock_irqrestore(&pcpu_lock, flags);

/* populate, map and clear the area */
if (pcpu_populate_chunk(chunk, off, size)) {
spin_lock_irq(&pcpu_lock);
spin_lock_irqsave(&pcpu_lock, flags);
pcpu_free_area(chunk, off);
err = "failed to populate";
goto fail_unlock;
Expand All @@ -1125,7 +1129,7 @@ static void *pcpu_alloc(size_t size, size_t align, bool reserved)
return __addr_to_pcpu_ptr(chunk->base_addr + off);

fail_unlock:
spin_unlock_irq(&pcpu_lock);
spin_unlock_irqrestore(&pcpu_lock, flags);
fail_unlock_mutex:
mutex_unlock(&pcpu_alloc_mutex);
if (warn_limit) {
Expand Down

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