From mboxrd@z Thu Jan 1 00:00:00 1970 From: mathieu.desnoyers@efficios.com (Mathieu Desnoyers) Date: Wed, 11 Aug 2010 10:13:42 -0400 Subject: [ltt-dev] [UST PATCH] UST synchronization fix Message-ID: <20100811141342.GA24267@Krystal> Missing smp_wmb() at subbuffer switch. Signed-off-by: Mathieu Desnoyers --- git/ust/libust/buffers.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) Index: ust/libust/buffers.c =================================================================== --- ust/libust/buffers.c 2010-08-10 16:16:39.000000000 -0400 +++ ust/libust/buffers.c 2010-08-10 16:19:59.000000000 -0400 @@ -858,7 +858,7 @@ static void ltt_reserve_switch_old_subbu * This compiler barrier is upgraded into a smp_wmb() by the IPI * sent by get_subbuf() when it does its smp_rmb(). */ - barrier(); + smp_wmb(); uatomic_add(&buf->commit_count[oldidx].cc, padding_size); commit_count = uatomic_read(&buf->commit_count[oldidx].cc); ltt_check_deliver(chan, buf, offsets->old - 1, commit_count, oldidx); @@ -887,7 +887,7 @@ static void ltt_reserve_switch_new_subbu * This compiler barrier is upgraded into a smp_wmb() by the IPI * sent by get_subbuf() when it does its smp_rmb(). */ - barrier(); + smp_wmb(); uatomic_add(&buf->commit_count[beginidx].cc, ltt_subbuffer_header_size()); commit_count = uatomic_read(&buf->commit_count[beginidx].cc); /* Check if the written buffer has to be delivered */ @@ -932,7 +932,7 @@ static void ltt_reserve_end_switch_curre * This compiler barrier is upgraded into a smp_wmb() by the IPI * sent by get_subbuf() when it does its smp_rmb(). */ - barrier(); + smp_wmb(); uatomic_add(&buf->commit_count[endidx].cc, padding_size); commit_count = uatomic_read(&buf->commit_count[endidx].cc); ltt_check_deliver(chan, buf, -- Mathieu Desnoyers Operating System Efficiency R&D Consultant EfficiOS Inc. http://www.efficios.com