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percpu_ida: Couple of tweaks

PATCH RESEND New Alexander Gordeev 1 participant 3 messages Apr 22, 2014

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Library code Per-CPU memory allocator
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Alexander Gordeev

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#0 lore raw

cover percpu_ida: Couple of tweaks

Hello,

The patches are against 3.15-rc2

Cc Kent Overstreet <[email protected]>
Cc Peter Zijlstra <[email protected]>
Cc Jens Axboe <[email protected]>
Cc "Nicholas A. Bellinger" <[email protected]>

Alexander Gordeev (2):
percpu_ida: Move waking up waiters out of atomic contexts
percpu_ida: Sanity check initialization parameters

 lib/percpu_ida.c |   17 ++++++++++++-----
 1 files changed, 12 insertions(+), 5 deletions(-)
Signature · 1 line
1.7.7.6
author
#1 lore raw

PATCH RESEND 1/2 percpu_ida: Move waking up waiters out of atomic contexts

Currently percpu_ida_free() waikes up waiters always with local interrupts disabled and sometimes with pool->lock held. Yet, it does not appear there is any reason why it could not be done out of these atomic contexts.

Signed-off-by Alexander Gordeev <[email protected]>
Cc Kent Overstreet <[email protected]>
Cc Peter Zijlstra <[email protected]>
Cc Jens Axboe <[email protected]>
Cc "Nicholas A. Bellinger" <[email protected]>
Acked-by Kent Overstreet <[email protected]>
Signed-off-by Alexander Gordeev <[email protected]>
---
 lib/percpu_ida.c |   12 +++++++-----
 1 files changed, 7 insertions(+), 5 deletions(-)
lib/percpu_ida.c +7 -5
index 93d145e..472ff08 100644
@@ -221,6 +221,7 @@ void percpu_ida_free(struct percpu_ida *pool, unsigned tag)
 	struct percpu_ida_cpu *tags;
 	unsigned long flags;
 	unsigned nr_free;
+	bool wake_up = false;
 
 	BUG_ON(tag >= pool->nr_tags);
 

@@ -234,9 +235,8 @@ void percpu_ida_free(struct percpu_ida *pool, unsigned tag)
 	spin_unlock(&tags->lock);
 
 	if (nr_free == 1) {
-		cpumask_set_cpu(smp_processor_id(),
-				&pool->cpus_have_tags);
-		wake_up(&pool->wait);
+		cpumask_set_cpu(smp_processor_id(), &pool->cpus_have_tags);
+		wake_up = true;
 	}
 
 	if (nr_free == pool->percpu_max_size) {

@@ -250,13 +250,15 @@ void percpu_ida_free(struct percpu_ida *pool, unsigned tag)
 			move_tags(pool->freelist, &pool->nr_free,
 				  tags->freelist, &tags->nr_free,
 				  pool->percpu_batch_size);
-
-			wake_up(&pool->wait);
+			wake_up = true;
 		}
 		spin_unlock(&pool->lock);
 	}
 
 	local_irq_restore(flags);
+
+	if (wake_up)
+		wake_up(&pool->wait);
 }
 EXPORT_SYMBOL_GPL(percpu_ida_free);
Signature · 1 line
1.7.7.6
author
#2 lore raw

PATCH RESEND 2/2 percpu_ida: Sanity check initialization parameters

In reply to Alexander Gordeev
Signed-off-by Alexander Gordeev <[email protected]>
Cc Kent Overstreet <[email protected]>
Cc Peter Zijlstra <[email protected]>
Cc Jens Axboe <[email protected]>
Cc "Nicholas A. Bellinger" <[email protected]>
Acked-by Kent Overstreet <[email protected]>
---
 lib/percpu_ida.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)
lib/percpu_ida.c +5 -0
index 472ff08..f474f03 100644
@@ -293,6 +293,11 @@ int __percpu_ida_init(struct percpu_ida *pool, unsigned long nr_tags,
 {
 	unsigned i, cpu, order;
 
+	if (batch_size > max_size)
+		return -ERANGE;
+	if (!batch_size)
+		return -EINVAL;
+
 	memset(pool, 0, sizeof(*pool));
 
 	init_waitqueue_head(&pool->wait);
Signature · 1 line
1.7.7.6