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=-9.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 969F0C3A5A7 for ; Tue, 3 Sep 2019 20:05:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6A1D820882 for ; Tue, 3 Sep 2019 20:05:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=joelfernandes.org header.i=@joelfernandes.org header.b="Bc9wK/zb" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726920AbfICUFR (ORCPT ); Tue, 3 Sep 2019 16:05:17 -0400 Received: from mail-pf1-f194.google.com ([209.85.210.194]:42898 "EHLO mail-pf1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726009AbfICUFQ (ORCPT ); Tue, 3 Sep 2019 16:05:16 -0400 Received: by mail-pf1-f194.google.com with SMTP id w22so3106295pfi.9 for ; Tue, 03 Sep 2019 13:05:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=joelfernandes.org; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=29Qri/KXgUDgYfdOZ88fjJJOMZcARQYfy1B4reZQb8c=; b=Bc9wK/zblLGMuThMFStgTMR+Yuk5YZw/2OmzZKkNBCmEcFehCD/s4K1pbKKLrFQA05 mPmHzEIztfOvQcEOIKXnzaWKwPLSifbtOQKvCSKx1ILGYfhNrkkFERSz53zkUM9YgF5j 2Qzq8rXeRv4y/MaRj50LsMtZJS/kv+gom5Ifo= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=29Qri/KXgUDgYfdOZ88fjJJOMZcARQYfy1B4reZQb8c=; b=G1qClCbmsxP02ciYIzUkxCCqjQUgRqRQK8GerZErkILo1rfWDdeNZSHWt2Z1YUXHlw xYlRotwblNlQ1xHgB7NQPTkNRVBWmR7kD19pl6g7Jpn5udFYz+lUgtUxPO7q0b93hjUU /JLYyUaWKv3gkpHechmA7bJsBP//ktbgyzd3hq+hUzQ+kJugk6O9Dx444NvHR3Zp7eIg wu45l10nQmkrMMu8rNr0Q1X2lH9x9p/CMA8A7yFeMzcQqw0mf4+9nmxQmUIs270NLTD7 7LIfFz4zxqwmj3ReoDPQ6kkexDk24i0nmEfXvLZVmgVVOYnuuFFkavPmMBtNGLzlUAOh CzEQ== X-Gm-Message-State: APjAAAU2IMwjeiUwT9DSrwgHnBCnOlb7UMv/8p8Gjbapkw1oDgIxjQoK a0jjKq+rH1C1AL2jFw5aTZ3jBe6j/Rw= X-Google-Smtp-Source: APXvYqzWwyyPykUJ8+f6u/buSmFd9exUPGkAK1eD0pBWdCTcvskP3nkPl9BvPjdTnUwebYQ7ayLfuA== X-Received: by 2002:a17:90a:d990:: with SMTP id d16mr1009540pjv.55.1567541114848; Tue, 03 Sep 2019 13:05:14 -0700 (PDT) Received: from joelaf.cam.corp.google.com ([2620:15c:6:12:9c46:e0da:efbf:69cc]) by smtp.gmail.com with ESMTPSA id k36sm16606308pgl.42.2019.09.03.13.05.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 03 Sep 2019 13:05:14 -0700 (PDT) From: "Joel Fernandes (Google)" To: linux-kernel@vger.kernel.org Cc: "Joel Fernandes (Google)" , Tim Murray , carmenjackson@google.com, mayankgupta@google.com, dancol@google.com, rostedt@goodmis.org, minchan@kernel.org, akpm@linux-foundation.org, kernel-team@android.com, "Aneesh Kumar K.V" , Dan Williams , "Jerome Glisse" , linux-mm@kvack.org, Matthew Wilcox , Michal Hocko , Ralph Campbell , Vlastimil Babka Subject: [PATCH] mm: emit tracepoint when RSS changes by threshold Date: Tue, 3 Sep 2019 16:05:03 -0400 Message-Id: <20190903200503.147973-1-joel@joelfernandes.org> X-Mailer: git-send-email 2.23.0.187.g17f5b7556c-goog MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Useful to track how RSS is changing per TGID. Several Android teams have been using this patch in various kernel trees for half a year now. Many reported to me it is really useful. Initial patch developed by Tim Murray. Changes I made from original patch: o Prevent any additional space consumed by mm_struct. o Keep overhead low by checking if tracing is enabled. o Add some noise reduction and lower overhead by emitting only on threshold changes. Co-developed-by: Tim Murray Signed-off-by: Tim Murray Signed-off-by: Joel Fernandes (Google) --- Cc: carmenjackson@google.com Cc: mayankgupta@google.com Cc: dancol@google.com Cc: rostedt@goodmis.org Cc: minchan@kernel.org Cc: akpm@linux-foundation.org Cc: kernel-team@android.com include/linux/mm.h | 14 +++++++++++--- include/trace/events/kmem.h | 21 +++++++++++++++++++++ mm/memory.c | 20 ++++++++++++++++++++ 3 files changed, 52 insertions(+), 3 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index 0334ca97c584..823aaf759bdb 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1671,19 +1671,27 @@ static inline unsigned long get_mm_counter(struct mm_struct *mm, int member) return (unsigned long)val; } +void mm_trace_rss_stat(int member, long count, long value); + static inline void add_mm_counter(struct mm_struct *mm, int member, long value) { - atomic_long_add(value, &mm->rss_stat.count[member]); + long count = atomic_long_add_return(value, &mm->rss_stat.count[member]); + + mm_trace_rss_stat(member, count, value); } static inline void inc_mm_counter(struct mm_struct *mm, int member) { - atomic_long_inc(&mm->rss_stat.count[member]); + long count = atomic_long_inc_return(&mm->rss_stat.count[member]); + + mm_trace_rss_stat(member, count, 1); } static inline void dec_mm_counter(struct mm_struct *mm, int member) { - atomic_long_dec(&mm->rss_stat.count[member]); + long count = atomic_long_dec_return(&mm->rss_stat.count[member]); + + mm_trace_rss_stat(member, count, -1); } /* Optimized variant when page is already known not to be PageAnon */ diff --git a/include/trace/events/kmem.h b/include/trace/events/kmem.h index eb57e3037deb..8b88e04fafbf 100644 --- a/include/trace/events/kmem.h +++ b/include/trace/events/kmem.h @@ -315,6 +315,27 @@ TRACE_EVENT(mm_page_alloc_extfrag, __entry->change_ownership) ); +TRACE_EVENT(rss_stat, + + TP_PROTO(int member, + long count), + + TP_ARGS(member, count), + + TP_STRUCT__entry( + __field(int, member) + __field(long, size) + ), + + TP_fast_assign( + __entry->member = member; + __entry->size = (count << PAGE_SHIFT); + ), + + TP_printk("member=%d size=%ldB", + __entry->member, + __entry->size) + ); #endif /* _TRACE_KMEM_H */ /* This part must be outside protection */ diff --git a/mm/memory.c b/mm/memory.c index e2bb51b6242e..9d81322c24a3 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -72,6 +72,8 @@ #include #include +#include + #include #include #include @@ -140,6 +142,24 @@ static int __init init_zero_pfn(void) } core_initcall(init_zero_pfn); +/* + * This threshold is the boundary in the value space, that the counter has to + * advance before we trace it. Should be a power of 2. It is to reduce unwanted + * trace overhead. The counter is in units of number of pages. + */ +#define TRACE_MM_COUNTER_THRESHOLD 128 + +void mm_trace_rss_stat(int member, long count, long value) +{ + long thresh_mask = ~(TRACE_MM_COUNTER_THRESHOLD - 1); + + if (!trace_rss_stat_enabled()) + return; + + /* Threshold roll-over, trace it */ + if ((count & thresh_mask) != ((count - value) & thresh_mask)) + trace_rss_stat(member, count); +} #if defined(SPLIT_RSS_COUNTING) -- 2.23.0.187.g17f5b7556c-goog