Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753054AbbLIRtX (ORCPT ); Wed, 9 Dec 2015 12:49:23 -0500 Received: from mail-pf0-f178.google.com ([209.85.192.178]:33313 "EHLO mail-pf0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752932AbbLIRtS (ORCPT ); Wed, 9 Dec 2015 12:49:18 -0500 From: Yang Shi To: akpm@linux-foundation.org, rostedt@goodmis.org, mingo@redhat.com Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, linaro-kernel@lists.linaro.org, yang.shi@linaro.org Subject: [RFC V4] Add gup trace points support Date: Wed, 9 Dec 2015 09:29:17 -0800 Message-Id: <1449682164-9933-1-git-send-email-yang.shi@linaro.org> X-Mailer: git-send-email 2.0.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2790 Lines: 72 v4: * Adopted Steven's suggestion to use "unsigned int" for nr_pages to save space in ring buffer since it is unlikely to have more than 0xffffffff pages are touched by gup in one invoke * Remove unnecessray type cast v3: * Adopted suggestion from Dave Hansen to move the gup header include to the last * Adopted comments from Steven: - Use DECLARE_EVENT_CLASS and DEFINE_EVENT - Just keep necessary TP_ARGS * Moved archtichture specific fall-backable fast version trace point after the do while loop since it may jump to the slow version. * Not implement recording return value since Steven plans to have it in generic tracing code v2: * Adopted commetns from Steven - remove all reference to tsk->comm since it is unnecessary for non-sched trace points - reduce arguments for __get_user_pages trace point and update mm/gup.c accordingly * Added Ralf's acked-by for patch 4/7. Some background about why I think this might be useful. When I was profiling some hugetlb related program, I got page-faults event doubled when hugetlb is enabled. When I looked into the code, I found page-faults come from two places, do_page_fault and gup. So, I tried to figure out which play a role (or both) in my use case. But I can't find existing finer tracing event for sub page-faults in current mainline kernel. So, I added the gup trace points support to have finer tracing events for page-faults. The below events are added: __get_user_pages __get_user_pages_fast fixup_user_fault Both __get_user_pages and fixup_user_fault call handle_mm_fault. Just added trace points to raw version __get_user_pages since all variants will call it finally to do real work. Although __get_user_pages_fast doesn't call handle_mm_fault, it might be useful to have it to distinguish between slow and fast version. Yang Shi (7): trace/events: Add gup trace events mm/gup: add gup trace points x86: mm/gup: add gup trace points mips: mm/gup: add gup trace points s390: mm/gup: add gup trace points sh: mm/gup: add gup trace points sparc64: mm/gup: add gup trace points arch/mips/mm/gup.c | 7 +++++++ arch/s390/mm/gup.c | 6 ++++++ arch/sh/mm/gup.c | 7 +++++++ arch/sparc/mm/gup.c | 7 +++++++ arch/x86/mm/gup.c | 7 +++++++ include/trace/events/gup.h | 63 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ mm/gup.c | 8 ++++++++ 7 files changed, 105 insertions(+) create mode 100644 include/trace/events/gup.h -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/