Merge branch 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu

* 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (30 commits)
  gameport: use this_cpu_read instead of lookup
  x86: udelay: Use this_cpu_read to avoid address calculation
  x86: Use this_cpu_inc_return for nmi counter
  x86: Replace uses of current_cpu_data with this_cpu ops
  x86: Use this_cpu_ops to optimize code
  vmstat: User per cpu atomics to avoid interrupt disable / enable
  irq_work: Use per cpu atomics instead of regular atomics
  cpuops: Use cmpxchg for xchg to avoid lock semantics
  x86: this_cpu_cmpxchg and this_cpu_xchg operations
  percpu: Generic this_cpu_cmpxchg() and this_cpu_xchg support
  percpu,x86: relocate this_cpu_add_return() and friends
  connector: Use this_cpu operations
  xen: Use this_cpu_inc_return
  taskstats: Use this_cpu_ops
  random: Use this_cpu_inc_return
  fs: Use this_cpu_inc_return in buffer.c
  highmem: Use this_cpu_xx_return() operations
  vmstat: Use this_cpu_inc_return for vm statistics
  x86: Support for this_cpu_add, sub, dec, inc_return
  percpu: Generic support for this_cpu_add, sub, dec, inc_return
  ...

Fixed up conflicts: in arch/x86/kernel/{apic/nmi.c, apic/x2apic_uv_x.c, process.c}
as per Tejun.

1 files changed, 18 insertions, 19 deletions

diff --git a/fs/buffer.c b/fs/buffer.c
index 5930e38..2219a76 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -1270,12 +1270,10 @@ static inline void check_irqs_on(void)
 static void bh_lru_install(struct buffer_head *bh)
 {
 	struct buffer_head *evictee = NULL;
-	struct bh_lru *lru;
 
 	check_irqs_on();
 	bh_lru_lock();
-	lru = &__get_cpu_var(bh_lrus);
-	if (lru->bhs[0] != bh) {
+	if (__this_cpu_read(bh_lrus.bhs[0]) != bh) {
 		struct buffer_head *bhs[BH_LRU_SIZE];
 		int in;
 		int out = 0;
@@ -1283,7 +1281,8 @@ static void bh_lru_install(struct buffer_head *bh)
 		get_bh(bh);
 		bhs[out++] = bh;
 		for (in = 0; in < BH_LRU_SIZE; in++) {
-			struct buffer_head *bh2 = lru->bhs[in];
+			struct buffer_head *bh2 =
+				__this_cpu_read(bh_lrus.bhs[in]);
 
 			if (bh2 == bh) {
 				__brelse(bh2);
@@ -1298,7 +1297,7 @@ static void bh_lru_install(struct buffer_head *bh)
 		}
 		while (out < BH_LRU_SIZE)
 			bhs[out++] = NULL;
-		memcpy(lru->bhs, bhs, sizeof(bhs));
+		memcpy(__this_cpu_ptr(&bh_lrus.bhs), bhs, sizeof(bhs));
 	}
 	bh_lru_unlock();
 
@@ -1313,23 +1312,22 @@ static struct buffer_head *
 lookup_bh_lru(struct block_device *bdev, sector_t block, unsigned size)
 {
 	struct buffer_head *ret = NULL;
-	struct bh_lru *lru;
 	unsigned int i;
 
 	check_irqs_on();
 	bh_lru_lock();
-	lru = &__get_cpu_var(bh_lrus);
 	for (i = 0; i < BH_LRU_SIZE; i++) {
-		struct buffer_head *bh = lru->bhs[i];
+		struct buffer_head *bh = __this_cpu_read(bh_lrus.bhs[i]);
 
 		if (bh && bh->b_bdev == bdev &&
 				bh->b_blocknr == block && bh->b_size == size) {
 			if (i) {
 				while (i) {
-					lru->bhs[i] = lru->bhs[i - 1];
+					__this_cpu_write(bh_lrus.bhs[i],
+						__this_cpu_read(bh_lrus.bhs[i - 1]));
 					i--;
 				}
-				lru->bhs[0] = bh;
+				__this_cpu_write(bh_lrus.bhs[0], bh);
 			}
 			get_bh(bh);
 			ret = bh;
@@ -3203,22 +3201,23 @@ static void recalc_bh_state(void)
 	int i;
 	int tot = 0;
 
-	if (__get_cpu_var(bh_accounting).ratelimit++ < 4096)
+	if (__this_cpu_inc_return(bh_accounting.ratelimit) - 1 < 4096)
 		return;
-	__get_cpu_var(bh_accounting).ratelimit = 0;
+	__this_cpu_write(bh_accounting.ratelimit, 0);
 	for_each_online_cpu(i)
 		tot += per_cpu(bh_accounting, i).nr;
 	buffer_heads_over_limit = (tot > max_buffer_heads);
 }
-	
+
 struct buffer_head *alloc_buffer_head(gfp_t gfp_flags)
 {
 	struct buffer_head *ret = kmem_cache_zalloc(bh_cachep, gfp_flags);
 	if (ret) {
 		INIT_LIST_HEAD(&ret->b_assoc_buffers);
-		get_cpu_var(bh_accounting).nr++;
+		preempt_disable();
+		__this_cpu_inc(bh_accounting.nr);
 		recalc_bh_state();
-		put_cpu_var(bh_accounting);
+		preempt_enable();
 	}
 	return ret;
 }
@@ -3228,9 +3227,10 @@ void free_buffer_head(struct buffer_head *bh)
 {
 	BUG_ON(!list_empty(&bh->b_assoc_buffers));
 	kmem_cache_free(bh_cachep, bh);
-	get_cpu_var(bh_accounting).nr--;
+	preempt_disable();
+	__this_cpu_dec(bh_accounting.nr);
 	recalc_bh_state();
-	put_cpu_var(bh_accounting);
+	preempt_enable();
 }
 EXPORT_SYMBOL(free_buffer_head);
 
@@ -3243,9 +3243,8 @@ static void buffer_exit_cpu(int cpu)
 		brelse(b->bhs[i]);
 		b->bhs[i] = NULL;
 	}
-	get_cpu_var(bh_accounting).nr += per_cpu(bh_accounting, cpu).nr;
+	this_cpu_add(bh_accounting.nr, per_cpu(bh_accounting, cpu).nr);
 	per_cpu(bh_accounting, cpu).nr = 0;
-	put_cpu_var(bh_accounting);
 }
 
 static int buffer_cpu_notify(struct notifier_block *self,