[PATCH RESEND 0/2] percpu_ida: Couple of tweaks

[PATCH RESEND 0/2] percpu_ida: Couple of tweaks

[Alexander Gordeev]

Hello,

The patches are against 3.15-rc2

Cc: Kent Overstreet <kmo@daterainc.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org>

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(-)

-- 
1.7.7.6

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

[Alexander Gordeev]

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 <agordeev@redhat.com>
Cc: Kent Overstreet <kmo@daterainc.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org>
Acked-by: Kent Overstreet <kmo@daterainc.com>

Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
---
 lib/percpu_ida.c |   12 +++++++-----
 1 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/lib/percpu_ida.c b/lib/percpu_ida.c
index 93d145e..472ff08 100644
--- a/lib/percpu_ida.c
+++ b/lib/percpu_ida.c
@@ -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);
 
-- 
1.7.7.6

[PATCH RESEND 2/2] percpu_ida: Sanity check initialization parameters

[Alexander Gordeev]

Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
Cc: Kent Overstreet <kmo@daterainc.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org>
Acked-by: Kent Overstreet <kmo@daterainc.com>
---
 lib/percpu_ida.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/lib/percpu_ida.c b/lib/percpu_ida.c
index 472ff08..f474f03 100644
--- a/lib/percpu_ida.c
+++ b/lib/percpu_ida.c
@@ -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);
-- 
1.7.7.6