From patchwork Wed Nov 24 20:43:35 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christophe JAILLET X-Patchwork-Id: 12637811 X-Patchwork-Delegate: jgg@ziepe.ca Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3E40EC433EF for ; Wed, 24 Nov 2021 20:44:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237232AbhKXUrU (ORCPT ); Wed, 24 Nov 2021 15:47:20 -0500 Received: from smtp02.smtpout.orange.fr ([80.12.242.124]:58216 "EHLO smtp.smtpout.orange.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236403AbhKXUrU (ORCPT ); Wed, 24 Nov 2021 15:47:20 -0500 Received: from pop-os.home ([86.243.171.122]) by smtp.orange.fr with ESMTPA id pz7BmRmGIBazopz7HmFJWk; Wed, 24 Nov 2021 21:44:05 +0100 X-ME-Helo: pop-os.home X-ME-Auth: YWZlNiIxYWMyZDliZWIzOTcwYTEyYzlhMmU3ZiQ1M2U2MzfzZDfyZTMxZTBkMTYyNDBjNDJlZmQ3ZQ== X-ME-Date: Wed, 24 Nov 2021 21:44:06 +0100 X-ME-IP: 86.243.171.122 From: Christophe JAILLET To: dledford@redhat.com, jgg@ziepe.ca Cc: linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org, Christophe JAILLET Subject: [PATCH 4/4] IB/mthca: Use non-atomic bitmap functions when possible in 'mthca_mr.c' Date: Wed, 24 Nov 2021 21:43:35 +0100 Message-Id: X-Mailer: git-send-email 2.30.2 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org In 'mthca_buddy_init()', the 'buddy->bits[n]' bitmap has just been allocated, so no concurrent accesses can occur. The other accesses to the 'buddy->bits[n]' bitmap are protected by the 'buddy->lock' spinlock, so no concurrent accesses can occur. So prefer the non-atomic '__[set|clear]_bit()' functions to save a few cycles. Signed-off-by: Christophe JAILLET --- drivers/infiniband/hw/mthca/mthca_mr.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/infiniband/hw/mthca/mthca_mr.c b/drivers/infiniband/hw/mthca/mthca_mr.c index 8892fcdbac4c..a59100c496b4 100644 --- a/drivers/infiniband/hw/mthca/mthca_mr.c +++ b/drivers/infiniband/hw/mthca/mthca_mr.c @@ -101,13 +101,13 @@ static u32 mthca_buddy_alloc(struct mthca_buddy *buddy, int order) return -1; found: - clear_bit(seg, buddy->bits[o]); + __clear_bit(seg, buddy->bits[o]); --buddy->num_free[o]; while (o > order) { --o; seg <<= 1; - set_bit(seg ^ 1, buddy->bits[o]); + __set_bit(seg ^ 1, buddy->bits[o]); ++buddy->num_free[o]; } @@ -125,13 +125,13 @@ static void mthca_buddy_free(struct mthca_buddy *buddy, u32 seg, int order) spin_lock(&buddy->lock); while (test_bit(seg ^ 1, buddy->bits[order])) { - clear_bit(seg ^ 1, buddy->bits[order]); + __clear_bit(seg ^ 1, buddy->bits[order]); --buddy->num_free[order]; seg >>= 1; ++order; } - set_bit(seg, buddy->bits[order]); + __set_bit(seg, buddy->bits[order]); ++buddy->num_free[order]; spin_unlock(&buddy->lock); @@ -158,7 +158,7 @@ static int mthca_buddy_init(struct mthca_buddy *buddy, int max_order) goto err_out_free; } - set_bit(0, buddy->bits[buddy->max_order]); + __set_bit(0, buddy->bits[buddy->max_order]); buddy->num_free[buddy->max_order] = 1; return 0;