From patchwork Wed Jan 30 09:54:59 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 10788121 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id EE11B13B4 for ; Wed, 30 Jan 2019 09:55:21 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D917829E85 for ; Wed, 30 Jan 2019 09:55:21 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id CD3732E124; Wed, 30 Jan 2019 09:55:21 +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=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, 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 7DDAB29E85 for ; Wed, 30 Jan 2019 09:55:21 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 273656EAFA; Wed, 30 Jan 2019 09:55:19 +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 8D3946EAF1; Wed, 30 Jan 2019 09:55:14 +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 15400302-1500050 for multiple; Wed, 30 Jan 2019 09:55:02 +0000 From: Chris Wilson To: intel-gfx@lists.freedesktop.org Date: Wed, 30 Jan 2019 09:54:59 +0000 Message-Id: <20190130095500.23596-7-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190130095500.23596-1-chris@chris-wilson.co.uk> References: <20190130095500.23596-1-chris@chris-wilson.co.uk> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH i-g-t 7/8] i915/gem_sync: Make switch-default asymmetric 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: , Cc: igt-dev@lists.freedesktop.org Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Virus-Scanned: ClamAV using ClamSMTP To make the demonstration of the cheeky preemption more impactful, make the second context a nop to contrast the first being 1024 MI_STORE_DWORD_IMM. Then if we execute and wait on the second context before executing the first, the client latency is even more drastically reduced. To more clearly show any effect on wait reordering, measure the alternative path and present both. Signed-off-by: Chris Wilson --- tests/i915/gem_sync.c | 40 +++++++++++++++++++++++++++++----------- 1 file changed, 29 insertions(+), 11 deletions(-) diff --git a/tests/i915/gem_sync.c b/tests/i915/gem_sync.c index fb209977d..3e4feff32 100644 --- a/tests/i915/gem_sync.c +++ b/tests/i915/gem_sync.c @@ -651,7 +651,7 @@ switch_ring(int fd, unsigned ring, int num_children, int timeout) struct drm_i915_gem_relocation_entry reloc[1024]; struct drm_i915_gem_execbuffer2 execbuf; } contexts[2]; - double start, elapsed; + double elapsed, baseline; unsigned long cycles; for (int i = 0; i < ARRAY_SIZE(contexts); i++) { @@ -679,7 +679,7 @@ switch_ring(int fd, unsigned ring, int num_children, int timeout) c->object[1].handle = gem_create(fd, sz); c->object[1].relocs_ptr = to_user_pointer(c->reloc); - c->object[1].relocation_count = 1024; + c->object[1].relocation_count = 1024 * i; batch = gem_mmap__cpu(fd, c->object[1].handle, 0, sz, PROT_WRITE | PROT_READ); @@ -688,7 +688,7 @@ switch_ring(int fd, unsigned ring, int num_children, int timeout) memset(c->reloc, 0, sizeof(c->reloc)); b = batch; - for (int r = 0; r < 1024; r++) { + for (int r = 0; r < c->object[1].relocation_count; r++) { uint64_t offset; c->reloc[r].presumed_offset = c->object[0].offset; @@ -722,26 +722,44 @@ switch_ring(int fd, unsigned ring, int num_children, int timeout) } cycles = 0; - elapsed = 0; - start = gettime(); - do { + baseline = 0; + igt_until_timeout(timeout) { do { double this; - gem_execbuf(fd, &contexts[0].execbuf); gem_execbuf(fd, &contexts[1].execbuf); + gem_execbuf(fd, &contexts[0].execbuf); this = gettime(); gem_sync(fd, contexts[1].object[1].handle); - elapsed += gettime() - this; + gem_sync(fd, contexts[0].object[1].handle); + baseline += gettime() - this; + } while (++cycles & 1023); + } + baseline /= cycles; + + cycles = 0; + elapsed = 0; + igt_until_timeout(timeout) { + do { + double this; + gem_execbuf(fd, &contexts[1].execbuf); + gem_execbuf(fd, &contexts[0].execbuf); + + this = gettime(); gem_sync(fd, contexts[0].object[1].handle); + elapsed += gettime() - this; + + gem_sync(fd, contexts[1].object[1].handle); } while (++cycles & 1023); - } while ((gettime() - start) < timeout); - igt_info("%s%sompleted %ld cycles: %.3f us\n", + } + elapsed /= cycles; + + igt_info("%s%sompleted %ld cycles: %.3f us, baseline %.3f us\n", names[child % num_engines] ?: "", names[child % num_engines] ? " c" : "C", - cycles, elapsed*1e6/cycles); + cycles, elapsed*1e6, baseline*1e6); for (int i = 0; i < ARRAY_SIZE(contexts); i++) { gem_close(fd, contexts[i].object[1].handle);