From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F0782C433FF for ; Mon, 5 Aug 2019 15:45:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C5B0F2086D for ; Mon, 5 Aug 2019 15:45:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="uUMttogE" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728058AbfHEPp7 (ORCPT ); Mon, 5 Aug 2019 11:45:59 -0400 Received: from mail-wr1-f67.google.com ([209.85.221.67]:40635 "EHLO mail-wr1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727259AbfHEPp7 (ORCPT ); Mon, 5 Aug 2019 11:45:59 -0400 Received: by mail-wr1-f67.google.com with SMTP id r1so84861114wrl.7 for ; Mon, 05 Aug 2019 08:45:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:subject:date:message-id:in-reply-to:references:mime-version :content-transfer-encoding; bh=rLPPYENgOoc631NZg5ylujQ9Ww/Oy03mgWH9mA4Vfho=; b=uUMttogETRTbgFeSAW6AxRt+C/hSaMGFvi3mp332QoCPwvz8IWurSQBJyJZOR7bOeh t3ZG8sKWLHmomyK1KkW6laa+1rkPlb2s6S7QLjGuLHIGU6mFCWzgKyX03MYFGac/PX3f 3FnoVZBhJNwniqasz7bjYzRcYHCGc7RShvCwvYl0KzWBYFpbx0kyIORqWht2191zBDHz Y3CTXzhkS44iwXBeQLT+vO4Z5kzpL6G5vo9DrLaozfCFZvMs+Wn9RBp8yQaEa0EJxXMd qPMg93CgzwNyEG7odpHdapiM1CXQ7Ke1wCd5xjdaY8/jfeVjVAiB9Ij2vv4o2WHx0ycg FPkQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=rLPPYENgOoc631NZg5ylujQ9Ww/Oy03mgWH9mA4Vfho=; b=G4GeJ8Ujej8hiPxTJ+mRMAJ0TgYOqBIZWbO+pm5nW3PX4T4GnAusjojbEd0CVK+iyX uBMNhANH4i265PyqITa4ujsjHBsSKGfgJMxfV4+vaLHd1cWNHv2ZkLFPHrBHOScbhmir /QRc/m32C2/6bPN2xwn9O6IOYApRZp0cT+Ipu9Bk2/oyPoTtSjgtQ48vKf36xVpyh7DL XZL7wrNcNu19oR9KY+aEsueEmXfYzTv/OczyJRINkMav8bvo8sIr00AvBr0v1JmwU3vQ kzO/A4i5Eq4NOMHT9P/JV3CdvRBBnD528940890jkiXOdJwfIqQlI8yDuPE1NhGCdkhe 1qnw== X-Gm-Message-State: APjAAAWsMSSCsdGeojAj6+/bZlPRzsM2n/yX04dEDCxOfidTsHSh47hI 6W6DjTot4L5A00xmtmHzRUBsJ45J X-Google-Smtp-Source: APXvYqzBprTtDw6edlmqIDiUmJARW7G/OtGF/lCyUR20zOiLqI+2QZmZi/Tqpnx0vU3E2ILqGfvMww== X-Received: by 2002:a5d:564e:: with SMTP id j14mr1799712wrw.1.1565019957178; Mon, 05 Aug 2019 08:45:57 -0700 (PDT) Received: from abel.fritz.box ([2a02:908:1252:fb60:fdbd:6233:4990:5a8d]) by smtp.gmail.com with ESMTPSA id 91sm171836865wrp.3.2019.08.05.08.45.56 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 05 Aug 2019 08:45:56 -0700 (PDT) From: "=?UTF-8?q?Christian=20K=C3=B6nig?=" X-Google-Original-From: =?UTF-8?q?Christian=20K=C3=B6nig?= To: intel-gfx@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, dri-devel@lists.freedesktop.org, linux-media@vger.kernel.org, chris@chris-wilson.co.uk Subject: [PATCH 2/5] dma-buf: fix busy wait for new shared fences Date: Mon, 5 Aug 2019 17:45:51 +0200 Message-Id: <20190805154554.3476-2-christian.koenig@amd.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190805154554.3476-1-christian.koenig@amd.com> References: <20190805154554.3476-1-christian.koenig@amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org When reservation_object_add_shared_fence is replacing an old fence with a new one we should not drop the old one before the new one is in place. Otherwise other cores can busy wait for the new one to appear. Signed-off-by: Christian König --- drivers/dma-buf/reservation.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/drivers/dma-buf/reservation.c b/drivers/dma-buf/reservation.c index c71b85c8c159..d59207ca72d2 100644 --- a/drivers/dma-buf/reservation.c +++ b/drivers/dma-buf/reservation.c @@ -196,6 +196,7 @@ void reservation_object_add_shared_fence(struct reservation_object *obj, struct dma_fence *fence) { struct reservation_object_list *fobj; + struct dma_fence *old; unsigned int i, count; dma_fence_get(fence); @@ -209,18 +210,16 @@ void reservation_object_add_shared_fence(struct reservation_object *obj, write_seqcount_begin(&obj->seq); for (i = 0; i < count; ++i) { - struct dma_fence *old_fence; - old_fence = rcu_dereference_protected(fobj->shared[i], - reservation_object_held(obj)); - if (old_fence->context == fence->context || - dma_fence_is_signaled(old_fence)) { - dma_fence_put(old_fence); + old = rcu_dereference_protected(fobj->shared[i], + reservation_object_held(obj)); + if (old->context == fence->context || + dma_fence_is_signaled(old)) goto replace; - } } BUG_ON(fobj->shared_count >= fobj->shared_max); + old = NULL; count++; replace: @@ -230,6 +229,7 @@ void reservation_object_add_shared_fence(struct reservation_object *obj, write_seqcount_end(&obj->seq); preempt_enable(); + dma_fence_put(old); } EXPORT_SYMBOL(reservation_object_add_shared_fence); -- 2.17.1