From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Nicholas A. Bellinger" Subject: [PATCH 8/9] vhost/scsi: Drop unnecessary wait_for_tasks=true usage with transport_generic_free_cmd Date: Fri, 7 Jun 2013 21:34:23 +0000 Message-ID: <1370640864-15568-9-git-send-email-nab@linux-iscsi.org> References: <1370640864-15568-1-git-send-email-nab@linux-iscsi.org> Return-path: Received: from mail.linux-iscsi.org ([67.23.28.174]:48638 "EHLO linux-iscsi.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756873Ab3FGVr6 (ORCPT ); Fri, 7 Jun 2013 17:47:58 -0400 In-Reply-To: <1370640864-15568-1-git-send-email-nab@linux-iscsi.org> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: target-devel Cc: linux-scsi , Christoph Hellwig , Roland Dreier , Kent Overstreet , Asias He , "Michael S. Tsirkin" , Or Gerlitz , Moussa Ba , Nicholas Bellinger From: Nicholas Bellinger This patch changes vhost_scsi_free_cmd() to call transport_generic_free_cmd() with wait_for_tasks=false in order to avoid the extra se_cmd->t_state_lock access for the wait_for_tasks=true case. This is unnecessary because vhost_scsi_free_cmd() is only ever called by vhost_scsi_complete_cmd_work() after TCM completion handoff, and by vhost_scsi_handle_vq() exception code before TCM submission handoff, so there is never a case where se_cmd is still active from TCM's perspective when transport_generic_free_cmd() is called. Cc: Christoph Hellwig Cc: Roland Dreier Cc: Kent Overstreet Cc: Asias He Cc: Michael S. Tsirkin Cc: Or Gerlitz Cc: Moussa Ba Signed-off-by: Nicholas Bellinger --- drivers/vhost/scsi.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c index 7014202..aacf71e 100644 --- a/drivers/vhost/scsi.c +++ b/drivers/vhost/scsi.c @@ -557,7 +557,7 @@ static void vhost_scsi_free_cmd(struct tcm_vhost_cmd *tv_cmd) struct se_cmd *se_cmd = &tv_cmd->tvc_se_cmd; /* TODO locking against target/backend threads? */ - transport_generic_free_cmd(se_cmd, 1); + transport_generic_free_cmd(se_cmd, 0); if (tv_cmd->tvc_sgl_count) { u32 i; -- 1.7.2.5