Received: by 2002:a25:8b91:0:0:0:0:0 with SMTP id j17csp260121ybl; Tue, 10 Dec 2019 22:27:02 -0800 (PST) X-Google-Smtp-Source: APXvYqzz2IQMu9AJQAaGo6YKSlS25trRFerU+9ySj9qVHtC/hS2/NpnQL9NV/FWJBM7IJNUNFlVk X-Received: by 2002:a54:468b:: with SMTP id k11mr1494538oic.134.1576045622080; Tue, 10 Dec 2019 22:27:02 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1576045622; cv=none; d=google.com; s=arc-20160816; b=eKeAKlu6VqtJBULDi6n/IesX/PDOu/+i0KYCoTaY0XIPhl5UzEaHMagki1IFYnmhhB GTysuL0DSMfxO/fYKAFH/sJ5mhusSY6EcriuzD4rvNYpUmPM9kRym7L8zFlPXXGU2Ult wMYxv9wkvIBLVu92DZeZv6KMHN9XHCTGGDZysN9qpZWTA2VvIpQ4/GfJCQlO32AMdtdb R7tA4jQ+Gd7C187nPG2cSa3eaIKfzKCkiHaVfwMxprgmFjNVqUjEAvUi1VbkXNsn58Ws T3bzFS9oTEZDeizeNtiIRHQUrPfdf6sqHg03SYlSaJ7VJJwHd4pSIVcG/dpx3gV7GOad B33Q== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:mime-version:message-id:date:references :in-reply-to:subject:cc:to:from; bh=nC4QUTWRbZ6VDaRN0cJX0b+NhOzp/XRki9uIY3mrsF8=; b=t7vuQTrYkfSvQb2yUG74N5+LswhDlk3CWOwJcFR05dfRlFWAmLWQrjNajupmoAnhik Gspy+FgqfklDo8iUCaq3ybUPQcRChrbJ2t+FS/9zhpdQgvV9f0zUInD6KmlyUynk+JEZ mYUVxJJkOhGIGqAlnzEYcLVVEtkWlzXG2nrvNc3BP8m2o8ds0jTrQEUYTnuEoWuUhgbZ Vgrc6xwh7D55LZau4Cj10+l4YrCEddIV4dHIGunuWuDcGKTDqkMdh1aYcPCRIQV69/ad TaKGfXB5cCd5v0vzSy/OotwKdOOzM6fVKmn747aXbs+B0g4vo0O8HFPM8r57cJqXCARW 2lrg== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=intel.com Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id p69si600098oic.32.2019.12.10.22.26.49; Tue, 10 Dec 2019 22:27:02 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=intel.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727187AbfLKG0R (ORCPT + 99 others); Wed, 11 Dec 2019 01:26:17 -0500 Received: from mga07.intel.com ([134.134.136.100]:19962 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726676AbfLKG0R (ORCPT ); Wed, 11 Dec 2019 01:26:17 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga105.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 10 Dec 2019 22:26:16 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.69,301,1571727600"; d="scan'208";a="225400285" Received: from um.fi.intel.com (HELO um) ([10.237.72.57]) by orsmga002.jf.intel.com with ESMTP; 10 Dec 2019 22:26:14 -0800 From: Alexander Shishkin To: Peter Zijlstra Cc: Arnaldo Carvalho de Melo , Ingo Molnar , linux-kernel@vger.kernel.org, Jiri Olsa Subject: Re: [PATCH 2/2] perf/x86/intel/bts: Fix the use of page_private() In-Reply-To: <20191211002334.GS2844@hirez.programming.kicks-ass.net> References: <20191205142853.28894-1-alexander.shishkin@linux.intel.com> <20191205142853.28894-3-alexander.shishkin@linux.intel.com> <20191211002334.GS2844@hirez.programming.kicks-ass.net> Date: Wed, 11 Dec 2019 08:26:13 +0200 Message-ID: <87h827cr96.fsf@ashishki-desk.ger.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Peter Zijlstra writes: >> static size_t buf_size(struct page *page) >> { >> - return 1 << (PAGE_SHIFT + page_private(page)); >> + return 1 << (PAGE_SHIFT + buf_nr_pages(page)); > > Hurmph, shouldn't that be: > > return buf_nr_pages(page) * PAGE_SIZE; > > ? True, that one's broken.