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 X-Spam-Level: X-Spam-Status: No, score=-5.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EE5F3C433E7 for ; Fri, 9 Oct 2020 12:29:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A020D22284 for ; Fri, 9 Oct 2020 12:29:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731467AbgJIM3a (ORCPT ); Fri, 9 Oct 2020 08:29:30 -0400 Received: from mga06.intel.com ([134.134.136.31]:28196 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726011AbgJIM3a (ORCPT ); Fri, 9 Oct 2020 08:29:30 -0400 IronPort-SDR: pbTyASPO5UrvShCN3Ey+lYF4yfGclNSJMg05vEHKVFWzJ63rQm4p0CTxkXPPfQmhi9bcCbft/D UsYs2o+3ONEw== X-IronPort-AV: E=McAfee;i="6000,8403,9768"; a="227125831" X-IronPort-AV: E=Sophos;i="5.77,355,1596524400"; d="scan'208";a="227125831" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Oct 2020 05:29:29 -0700 IronPort-SDR: brXMhEC7edjubEjxgKYipSodYTOetuw4sSXc7kdr+55p2nw/DYer2MUcKjs9fK7nbAnmFn6pLm MAu2yGF63+5Q== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.77,355,1596524400"; d="scan'208";a="349813720" Received: from linux.intel.com ([10.54.29.200]) by fmsmga002.fm.intel.com with ESMTP; 09 Oct 2020 05:29:28 -0700 Received: from [10.251.2.196] (kliang2-MOBL.ccr.corp.intel.com [10.251.2.196]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by linux.intel.com (Postfix) with ESMTPS id DDB085807BA; Fri, 9 Oct 2020 05:29:26 -0700 (PDT) Subject: Re: [PATCH V9 1/4] perf/core: Add PERF_SAMPLE_DATA_PAGE_SIZE To: Peter Zijlstra Cc: mingo@redhat.com, acme@kernel.org, linux-kernel@vger.kernel.org, mark.rutland@arm.com, alexander.shishkin@linux.intel.com, jolsa@redhat.com, eranian@google.com, ak@linux.intel.com, dave.hansen@intel.com, kirill.shutemov@linux.intel.com, mpe@ellerman.id.au, benh@kernel.crashing.org, paulus@samba.org, Will Deacon , David Miller References: <20201001135749.2804-1-kan.liang@linux.intel.com> <20201001135749.2804-2-kan.liang@linux.intel.com> <20201009090927.GQ2611@hirez.programming.kicks-ass.net> From: "Liang, Kan" Message-ID: Date: Fri, 9 Oct 2020 08:29:25 -0400 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.12.1 MIME-Version: 1.0 In-Reply-To: <20201009090927.GQ2611@hirez.programming.kicks-ass.net> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/9/2020 5:09 AM, Peter Zijlstra wrote: > (we might not need the #ifdef gunk, but I've not yet dug out my cross > compilers this morning) > > --- > --- a/kernel/events/core.c > +++ b/kernel/events/core.c > @@ -7009,6 +7009,7 @@ static u64 perf_virt_to_phys(u64 virt) > */ > static u64 __perf_get_page_size(struct mm_struct *mm, unsigned long addr) > { > + struct page *page; > pgd_t *pgd; > p4d_t *p4d; > pud_t *pud; > @@ -7030,15 +7031,27 @@ static u64 __perf_get_page_size(struct m > if (!pud_present(*pud)) > return 0; > > - if (pud_leaf(*pud)) > + if (pud_leaf(*pud)) { > +#ifdef pud_page > + page = pud_page(*pud); > + if (PageHuge(page)) > + return page_size(compound_head(page)); I think the page_size() returns the Kernel Page Size of a compound page. What we want is the MMU page size. If it's for the generic code, I think it should be a problem for X86. Thanks, Kan > +#endif > return 1ULL << PUD_SHIFT; > + } > > pmd = pmd_offset(pud, addr); > if (!pmd_present(*pmd)) > return 0; > > - if (pmd_leaf(*pmd)) > + if (pmd_leaf(*pmd)) { > +#ifdef pmd_page > + page = pmd_page(*pmd); > + if (PageHuge(page)) > + return page_size(compound_head(page)); > +#endif > return 1ULL << PMD_SHIFT; > + } > > pte = pte_offset_map(pmd, addr); > if (!pte_present(*pte)) { > @@ -7046,6 +7059,10 @@ static u64 __perf_get_page_size(struct m > return 0; > } > > + page = pte_page(*pte); > + if (PageHuge(page)) > + return page_size(compound_head(page)); > + > pte_unmap(pte); > return PAGE_SIZE; > }