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=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 5BEE3C282D8 for ; Fri, 1 Feb 2019 10:04:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 299B821872 for ; Fri, 1 Feb 2019 10:04:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="2Urk20sR" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728575AbfBAKES (ORCPT ); Fri, 1 Feb 2019 05:04:18 -0500 Received: from merlin.infradead.org ([205.233.59.134]:43876 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725765AbfBAKES (ORCPT ); Fri, 1 Feb 2019 05:04:18 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=97/9n2CCeAYRmqzj2PHTmcvZtFuC6J6rYX8ZULmEc98=; b=2Urk20sRg0ghbTdcCm3X0+1eH XHE1H73s11sgwzDm5viiVGJ0MYZFPqTnuaXTEUVYD79Gq01OnhhDW9ONN4Ou/THf+92iI8fBPLWu6 CAWRCwRG3woTsPl+RheNQCDpwuPnqPl1028HjhF7ogrfAO3YTgaDH4Ycx9Bl18mljyeFer4QLEn5T uUox4O33+17cxAfoy4ZNROmJpNfm1SGLJLt+xcVKsrOxG+J96h/Kq+p6RNAEO74aJz3/wdfOD97sj Ztjkb13PQFKBOnIjEOa9PFGmhTxv11ni7cALWi5pIhZChvjmIk69ILEIsBXiYKb1bcJCrDN/zYPwi NU9SaTjJA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1gpVg0-0007EU-9I; Fri, 01 Feb 2019 10:04:00 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id DBF5D202E51F5; Fri, 1 Feb 2019 11:03:58 +0100 (CET) Date: Fri, 1 Feb 2019 11:03:58 +0100 From: Peter Zijlstra To: kan.liang@linux.intel.com Cc: acme@kernel.org, tglx@linutronix.de, mingo@redhat.com, linux-kernel@vger.kernel.org, eranian@google.com, jolsa@redhat.com, namhyung@kernel.org, ak@linux.intel.com, luto@amacapital.net, Vlastimil Babka , kirill@shutemov.name, Will Deacon Subject: Re: [PATCH V4 01/13] perf/core, x86: Add PERF_SAMPLE_DATA_PAGE_SIZE Message-ID: <20190201100358.GD31552@hirez.programming.kicks-ass.net> References: <1548966486-49963-1-git-send-email-kan.liang@linux.intel.com> <20190201092240.GB31498@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190201092240.GB31498@hirez.programming.kicks-ass.net> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Feb 01, 2019 at 10:22:40AM +0100, Peter Zijlstra wrote: > +static u64 __perf_get_page_size(struct mm_struct *mm, unsigned long addr) > { > + pgd_t *pgd; > + p4d_t *p4d; > + pud_t *pud; > + pmd_t *pmd; > + > + pgd = pgd_offset(mm, addr); > + if (pgd_none(*pgd)) > + return 0; > + > + p4d = p4d_offset(pgd, addr); > + if (p4d_none(*p4d)) > + return 0; > + > + if (p4d_large(*p4d)); > + return 1ULL << P4D_SHIFT; > + > + if (!p4d_present(*p4d)) > + return 0; > + > + pud = pud_offset(p4d, addr); > + if (pud_none(*pud)) > + return 0; > + > + if (pud_large(*pud)) > + return 1ULL << PUD_SHIFT; Will just mentioned a lovely feature where some archs have multi entry large pages. Possible something like: if (pud_large(*pud)) { struct page *page = pud_page(*pud); int order = PUD_SHIFT; if (PageHuge(page)) { page = compound_head(page); order += compound_order(page); } return 1ULL << order; } works correctly. > + > + if (!pud_present(*pud)) > + return 0; > + > + pmd = pmd_offset(pud, addr); > + if (pmd_none(*pmd)) > + return 0; > + > + if (pmd_large(*pmd)) > + return 1ULL << PMD_SHIFT; And same here I suppose.. > + > + if (!pmd_present(*pmd)) > + return 0; > + > + return 1ULL << PAGE_SHIFT; > +}