From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gerald Schaefer Subject: [PATCH] net: rds: fix per-cpu helper usage Date: Thu, 16 Jan 2014 16:54:48 +0100 Message-ID: <1389887688-55632-1-git-send-email-gerald.schaefer@de.ibm.com> Cc: rds-devel@oss.oracle.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Martin Schwidefsky , Frank Blaschka , Sebastian Ott , Gerald Schaefer To: Shan Wei , Christoph Lameter , "David S. Miller" , Venkat Venkatsubra Return-path: Received: from e06smtp18.uk.ibm.com ([195.75.94.114]:56865 "EHLO e06smtp18.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751625AbaAPPyy (ORCPT ); Thu, 16 Jan 2014 10:54:54 -0500 Received: from /spool/local by e06smtp18.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 16 Jan 2014 15:54:52 -0000 Sender: netdev-owner@vger.kernel.org List-ID: 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. Cc: # 3.8+ Signed-off-byd Gerald Schaefer --- net/rds/ib_recv.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/net/rds/ib_recv.c b/net/rds/ib_recv.c index 8eb9501..b7ebe23 100644 --- a/net/rds/ib_recv.c +++ b/net/rds/ib_recv.c @@ -421,8 +421,7 @@ static void rds_ib_recv_cache_put(struct list_head *new_item, 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 list_head *new_item, 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 list_head *new_item, } 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); -- 1.8.4.5