From patchwork Tue Jan 16 13:15:07 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 10166829 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 02C01600CA for ; Tue, 16 Jan 2018 13:15:25 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EA04228446 for ; Tue, 16 Jan 2018 13:15:24 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id DE53128516; Tue, 16 Jan 2018 13:15:24 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 6ADB528522 for ; Tue, 16 Jan 2018 13:15:24 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id E800B6E20E; Tue, 16 Jan 2018 13:15:23 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from fireflyinternet.com (mail.fireflyinternet.com [109.228.58.192]) by gabe.freedesktop.org (Postfix) with ESMTPS id 23C3E6E20E for ; Tue, 16 Jan 2018 13:15:21 +0000 (UTC) X-Default-Received-SPF: pass (skip=forwardok (res=PASS)) x-ip-name=78.156.65.138; Received: from haswell.alporthouse.com (unverified [78.156.65.138]) by fireflyinternet.com (Firefly Internet (M1)) with ESMTP id 10337039-1500050 for multiple; Tue, 16 Jan 2018 13:15:06 +0000 Received: by haswell.alporthouse.com (sSMTP sendmail emulation); Tue, 16 Jan 2018 13:15:08 +0000 From: Chris Wilson To: intel-gfx@lists.freedesktop.org Date: Tue, 16 Jan 2018 13:15:07 +0000 Message-Id: <20180116131507.7791-1-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.15.1 In-Reply-To: <90eb4cff-4918-4c49-fda4-345e98842bcf@linux.intel.com> References: <90eb4cff-4918-4c49-fda4-345e98842bcf@linux.intel.com> X-Originating-IP: 78.156.65.138 X-Country: code=GB country="United Kingdom" ip=78.156.65.138 Subject: [Intel-gfx] [PATCH v2] drm/i915: Shrink the request kmem_cache on allocation error X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Virus-Scanned: ClamAV using ClamSMTP If we fail to allocate a new request, make sure we recover the pages that are in the process of being freed by inserting an RCU barrier. v2: Comment before the shrink and barrier in the error path. Signed-off-by: Chris Wilson Cc: Tvrtko Ursulin Reviewed-by: Tvrtko Ursulin --- drivers/gpu/drm/i915/i915_gem_request.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_gem_request.c b/drivers/gpu/drm/i915/i915_gem_request.c index 72bdc203716f..a0f451b4a4e8 100644 --- a/drivers/gpu/drm/i915/i915_gem_request.c +++ b/drivers/gpu/drm/i915/i915_gem_request.c @@ -696,6 +696,17 @@ i915_gem_request_alloc(struct intel_engine_cs *engine, if (ret) goto err_unreserve; + /* + * We've forced the client to stall and catch up with whatever + * backlog there might have been. As we are assuming that we + * caused the mempressure, now is an opportune time to + * recover as much memory from the request pool as is possible. + * Having already penalized the client to stall, we spend + * a little extra time to re-optimise page allocation. + */ + kmem_cache_shrink(dev_priv->requests); + rcu_barrier(); /* Recover the TYPESAFE_BY_RCU pages */ + req = kmem_cache_alloc(dev_priv->requests, GFP_KERNEL); if (!req) { ret = -ENOMEM;