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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3C963C433EF for ; Fri, 22 Apr 2022 22:25:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232159AbiDVW2s (ORCPT ); Fri, 22 Apr 2022 18:28:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36738 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234313AbiDVW2g (ORCPT ); Fri, 22 Apr 2022 18:28:36 -0400 Received: from smtp-fw-6002.amazon.com (smtp-fw-6002.amazon.com [52.95.49.90]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BF7721A0B23; Fri, 22 Apr 2022 14:22:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1650662580; x=1682198580; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=pIf8XjvVOLM926gmhXXRBBK1J3Op2QCT6Rw8kAViYLM=; b=n7DOI4VDYzR+FeJr/AzEpv/QIIzjQ9Nn9PxTsWFlWxh11NG5JXfc/f8Q hKAhxt841hKGcu9DFnMfK7AZs5/cVzfTTmlQzQH/EYyyapUByYoCtzIQw lxKRo99HXJzd6IRJTO5dhYuXuzmPYyfJM+mnG5uIGiqLVcWPRNt56JF3q k=; X-IronPort-AV: E=Sophos;i="5.90,282,1643673600"; d="scan'208";a="195599088" Received: from iad12-co-svc-p1-lb1-vlan2.amazon.com (HELO email-inbound-relay-iad-1a-b27d4a00.us-east-1.amazon.com) ([10.43.8.2]) by smtp-border-fw-6002.iad6.amazon.com with ESMTP; 22 Apr 2022 21:22:58 +0000 Received: from EX13MTAUWB001.ant.amazon.com (iad12-ws-svc-p26-lb9-vlan3.iad.amazon.com [10.40.163.38]) by email-inbound-relay-iad-1a-b27d4a00.us-east-1.amazon.com (Postfix) with ESMTPS id 9E8C68129B; Fri, 22 Apr 2022 21:22:52 +0000 (UTC) Received: from EX13D02UWB001.ant.amazon.com (10.43.161.240) by EX13MTAUWB001.ant.amazon.com (10.43.161.207) with Microsoft SMTP Server (TLS) id 15.0.1497.32; Fri, 22 Apr 2022 21:22:51 +0000 Received: from EX13MTAUWA001.ant.amazon.com (10.43.160.58) by EX13D02UWB001.ant.amazon.com (10.43.161.240) with Microsoft SMTP Server (TLS) id 15.0.1497.32; Fri, 22 Apr 2022 21:22:51 +0000 Received: from dev-dsk-alisaidi-1d-b9a0e636.us-east-1.amazon.com (172.19.181.128) by mail-relay.amazon.com (10.43.160.118) with Microsoft SMTP Server id 15.0.1497.32 via Frontend Transport; Fri, 22 Apr 2022 21:22:52 +0000 Received: by dev-dsk-alisaidi-1d-b9a0e636.us-east-1.amazon.com (Postfix, from userid 5131138) id 8D417D86; Fri, 22 Apr 2022 21:22:50 +0000 (UTC) From: Ali Saidi To: CC: , , , , , , , , , , , , , , , , , , , , , , Subject: Re: [PATCH v5 2/5] perf: Add SNOOP_PEER flag to perf mem data struct Date: Fri, 22 Apr 2022 21:22:49 +0000 Message-ID: <20220422212249.22463-1-alisaidi@amazon.com> X-Mailer: git-send-email 2.32.0 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-perf-users@vger.kernel.org On Fri, 22 Apr 2022 21:43:28, Kan Liang wrote: > On 4/22/2022 2:49 PM, Ali Saidi wrote: > > On Wed, 20 Apr 2022 18:43:28, Kan Liang wrote: > >> On 4/8/2022 3:53 PM, Ali Saidi wrote: > >>> Add a flag to the perf mem data struct to signal that a request caused a > >>> cache-to-cache transfer of a line from a peer of the requestor and > >>> wasn't sourced from a lower cache level. > >> > >> It sounds similar to the Forward state. Why can't the > >> PERF_MEM_SNOOPX_FWD be reused? > > > > Is there a definition of SNOOPX_FWD i can refer to? Happy to use this instead if > > the semantics align between architectures. > > > > + Andi > > As my understanding, the SNOOPX_FWD means the Forward state, which is a > non-modified (clean) cache-to-cache copy. > https://en.wikipedia.org/wiki/MESIF_protocol In this case the semantics are different. We know the line was transferred from another peer cache, but don't know if it was clean, dirty, or if the receiving core now has exclusive ownership of it. Thanks, Ali