[PATCH 3.12 106/133] net: rds: fix per-cpu helper usage

Greg Kroah-Hartman
2014-02-04T21:09:36Z

From: Gerald Schaefer <gerald.schaefer@de.ibm.com>

[ Upstream commit c196403b79aa241c3fefb3ee5bb328aa7c5cc860 ]

commit ae4b46e9d "net: rds: use this_cpu_* per-cpu helper" broke per-cpu
handling for rds. chpfirst is the result of __this_cpu_read(), so it is
an absolute pointer and not __percpu. Therefore, __this_cpu_write()
should not operate on chpfirst, but rather on cache->percpu->first, just
like __this_cpu_read() did before.

Signed-off-byd Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/rds/ib_recv.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)

--- a/net/rds/ib_recv.c
+++ b/net/rds/ib_recv.c
@@ -421,8 +421,7 @@ static void rds_ib_recv_cache_put(struct
struct rds_ib_refill_cache *cache)
{
unsigned long flags;
- struct list_head *old;
- struct list_head __percpu *chpfirst;
+ struct list_head *old, *chpfirst;

local_irq_save(flags);

@@ -432,7 +431,7 @@ static void rds_ib_recv_cache_put(struct
else /* put on front */
list_add_tail(new_item, chpfirst);

- __this_cpu_write(chpfirst, new_item);
+ __this_cpu_write(cache->percpu->first, new_item);
__this_cpu_inc(cache->percpu->count);

if (__this_cpu_read(cache->percpu->count) < RDS_IB_RECYCLE_BATCH_COUNT)
@@ -452,7 +451,7 @@ static void rds_ib_recv_cache_put(struct
} while (old);

- __this_cpu_write(chpfirst, NULL);
+ __this_cpu_write(cache->percpu->first, NULL);
__this_cpu_write(cache->percpu->count, 0);
end:
local_irq_restore(flags);