From patchwork Fri Sep 25 11:57:27 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lucas Stach X-Patchwork-Id: 7263651 Return-Path: X-Original-To: patchwork-dri-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 0535EBEEC1 for ; Fri, 25 Sep 2015 11:58:32 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 1E6B620B17 for ; Fri, 25 Sep 2015 11:58:31 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by mail.kernel.org (Postfix) with ESMTP id 7923120AFD for ; Fri, 25 Sep 2015 11:58:26 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id EFC5CA541; Fri, 25 Sep 2015 04:58:09 -0700 (PDT) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from metis.ext.pengutronix.de (metis.ext.4.pengutronix.de [92.198.50.35]) by gabe.freedesktop.org (Postfix) with ESMTPS id BD6066F095 for ; Fri, 25 Sep 2015 04:58:04 -0700 (PDT) Received: from weser.hi.4.pengutronix.de ([10.1.0.109] helo=weser.pengutronix.de.) by metis.ext.pengutronix.de with esmtp (Exim 4.80) (envelope-from ) id 1ZfRda-0004Em-CH; Fri, 25 Sep 2015 13:58:02 +0200 From: Lucas Stach To: Russell King , Christian Gmeiner Subject: [PATCH 15/48] staging: etnaviv: etnaviv_gem_fault: reduce struct_mutex exposure Date: Fri, 25 Sep 2015 13:57:27 +0200 Message-Id: <1443182280-15868-16-git-send-email-l.stach@pengutronix.de> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1443182280-15868-1-git-send-email-l.stach@pengutronix.de> References: <20150916080435.GA21084@n2100.arm.linux.org.uk> <1443182280-15868-1-git-send-email-l.stach@pengutronix.de> X-SA-Exim-Connect-IP: 10.1.0.109 X-SA-Exim-Mail-From: l.stach@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: dri-devel@lists.freedesktop.org Cc: dri-devel@lists.freedesktop.org X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Russell King Reduce the exposure of struct_mutex to an absolute minimum. We only need to take this lock over the call to etnaviv_gem_get_pages() as vm_insert_page() already does a properly synchronised update of the PTE (using the pte table lock.) Reducing the code covered by this lock allows for more parallel execution in SMP environments. Signed-off-by: Russell King --- drivers/staging/etnaviv/etnaviv_gem.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/drivers/staging/etnaviv/etnaviv_gem.c b/drivers/staging/etnaviv/etnaviv_gem.c index 69360c899b78..522e5a6c3612 100644 --- a/drivers/staging/etnaviv/etnaviv_gem.c +++ b/drivers/staging/etnaviv/etnaviv_gem.c @@ -221,8 +221,10 @@ int etnaviv_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf) pgoff_t pgoff; int ret; - /* Make sure we don't parallel update on a fault, nor move or remove - * something from beneath our feet + /* + * Make sure we don't parallel update on a fault, nor move or remove + * something from beneath our feet. Note that vm_insert_page() is + * specifically coded to take care of this, so we don't have to. */ ret = mutex_lock_interruptible(&dev->struct_mutex); if (ret) @@ -230,9 +232,11 @@ int etnaviv_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf) /* make sure we have pages attached now */ pages = etnaviv_gem_get_pages(to_etnaviv_bo(obj)); + mutex_unlock(&dev->struct_mutex); + if (IS_ERR(pages)) { ret = PTR_ERR(pages); - goto out_unlock; + goto out; } /* We don't use vmf->pgoff since that has the fake offset: */ @@ -246,8 +250,6 @@ int etnaviv_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf) ret = vm_insert_page(vma, (unsigned long)vmf->virtual_address, page); -out_unlock: - mutex_unlock(&dev->struct_mutex); out: switch (ret) { case -EAGAIN: