From patchwork Sun Nov 10 18:57:47 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 11236305 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 7993D14E5 for ; Sun, 10 Nov 2019 18:58:44 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 6075120842 for ; Sun, 10 Nov 2019 18:58:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6075120842 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=chris-wilson.co.uk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=intel-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id F20F46E7B0; Sun, 10 Nov 2019 18:58:34 +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 DC3066E7AD for ; Sun, 10 Nov 2019 18:58:28 +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 19151886-1500050 for multiple; Sun, 10 Nov 2019 18:58:10 +0000 From: Chris Wilson To: intel-gfx@lists.freedesktop.org Date: Sun, 10 Nov 2019 18:57:47 +0000 Message-Id: <20191110185806.17413-6-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191110185806.17413-1-chris@chris-wilson.co.uk> References: <20191110185806.17413-1-chris@chris-wilson.co.uk> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH 06/25] drm/i915/userptr: Handle unlocked gup retries X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" Enable gup to retry and fault the pages outside of the mmap_sem lock in our worker. As we are inside our worker, outside of any critical path, we can allow the mmap_sem lock to be dropped in order to service a page fault; this in turn allows the mm to populate the page using a slow fault handler. Testcase: igt/gem_userptr/userfault Signed-off-by: Chris Wilson Cc: Tvrtko Ursulin --- drivers/gpu/drm/i915/gem/i915_gem_userptr.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c index ee65c6acf0e2..5e87126def2f 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c @@ -459,26 +459,31 @@ __i915_gem_userptr_get_pages_worker(struct work_struct *_work) if (pvec != NULL) { struct mm_struct *mm = obj->userptr.mm->mm; unsigned int flags = 0; + int locked = 0; if (!i915_gem_object_is_readonly(obj)) flags |= FOLL_WRITE; ret = -EFAULT; if (mmget_not_zero(mm)) { - down_read(&mm->mmap_sem); while (pinned < npages) { + if (!locked) { + down_read(&mm->mmap_sem); + locked = 1; + } ret = get_user_pages_remote (work->task, mm, obj->userptr.ptr + pinned * PAGE_SIZE, npages - pinned, flags, - pvec + pinned, NULL, NULL); + pvec + pinned, NULL, &locked); if (ret < 0) break; pinned += ret; } - up_read(&mm->mmap_sem); + if (locked) + up_read(&mm->mmap_sem); mmput(mm); } }