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=-14.3 required=3.0 tests=DKIMWL_WL_MED,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_IN_DEF_DKIM_WL 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 B495BC3A59E for ; Wed, 4 Sep 2019 05:38:44 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 4D6E820870 for ; Wed, 4 Sep 2019 05:38:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="F1CINYHy" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4D6E820870 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id B6A366B0007; Wed, 4 Sep 2019 01:38:43 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B1ADA6B0008; Wed, 4 Sep 2019 01:38:43 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A57976B000A; Wed, 4 Sep 2019 01:38:43 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0161.hostedemail.com [216.40.44.161]) by kanga.kvack.org (Postfix) with ESMTP id 843A06B0007 for ; Wed, 4 Sep 2019 01:38:43 -0400 (EDT) Received: from smtpin20.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with SMTP id 2513E824CA3E for ; Wed, 4 Sep 2019 05:38:43 +0000 (UTC) X-FDA: 75896133726.20.chess33_4c0898c142026 X-HE-Tag: chess33_4c0898c142026 X-Filterd-Recvd-Size: 9962 Received: from mail-wm1-f66.google.com (mail-wm1-f66.google.com [209.85.128.66]) by imf41.hostedemail.com (Postfix) with ESMTP for ; Wed, 4 Sep 2019 05:38:42 +0000 (UTC) Received: by mail-wm1-f66.google.com with SMTP id t17so1783514wmi.2 for ; Tue, 03 Sep 2019 22:38:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=DjkIYBZ84wViixpo736u9BuUnFigJEHvSnUL+P/PBcU=; b=F1CINYHyzlUuWZl/czJ2J2eXoJ6RO+aZjWVtRRvpQ04XNip4g1qvS0SnTm7MmvFS1y KTr7bBI5MOxx+H9tbQgMgTKNDeirqidEiQWdHM89bcFP84N1uP0D1OJL318t8mxafI9d 6UFhEQsMAEsmzotDK/cUepM1Js+mpP9wFQ4jdq8o+TbgsrMTeMzKlynQMg5rPBKU5DeL EEVxthZVl8ZNhLB+7KXynM4h/jFTP7LAQ15SE3BQYZlDbcXL6IfzlAJbAOJswPmcsXTJ 5mWWyU+nuBCPrtP9IFWLawEU53OQuWdaio5HmNoxHn89B5GZ39pSvwLVxK8wlHcnkbv3 VtLw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=DjkIYBZ84wViixpo736u9BuUnFigJEHvSnUL+P/PBcU=; b=JWZ3CEO351dR3qBFMdIWNvVPQoqWkLYaV7/XW51zv0/q3D2Sr9E7DhKGmuylXN6UcD YMqIM/IYs8/0zqw9MgXvn1b8Lqrvf7xUcwPKAeZvPl5Fv/ExyAHjtcNsnaM1hPIeZWST 5uE4LXbmLHttSNJ6+2bi0g/ed8i47GvAYBDTAJ1sOwLxOHl5bFDMFkHIWcEQuzz1x+t4 NEiy/V2/s5WJvwl1X0k+nb3OCAILGI9epedmJL/HbuzYzsZuphmxfhBYBtCTnQgQHg8D lwV4Tu6Anbr0IWMLNVVoWYintfo/gxACriSWvCLuI9uiyX8DeNbSx5XyWrSsbOEuqGXi 4Law== X-Gm-Message-State: APjAAAUBE8BDpZ8z6H4avhGy5CoJNBTxJOmfhf15k8GCN6AAe/lTNCZM sONtViBlGMmya22p5mHqwID1g7IQR/mj9aT/ke9l0w== X-Google-Smtp-Source: APXvYqzFPPpVWAqotpZJ/8I6yBwvNX3PeJCESPEiyFpyvXZYHeO7T3dOG/NOPNEfyRJ0xEytKCyVCGrAuk59O0c0BqQ= X-Received: by 2002:a1c:80d0:: with SMTP id b199mr2723540wmd.102.1567575520837; Tue, 03 Sep 2019 22:38:40 -0700 (PDT) MIME-Version: 1.0 References: <20190903200905.198642-1-joel@joelfernandes.org> <20190904050240.GD144846@google.com> In-Reply-To: <20190904050240.GD144846@google.com> From: Suren Baghdasaryan Date: Tue, 3 Sep 2019 22:38:29 -0700 Message-ID: Subject: Re: [PATCH v2] mm: emit tracepoint when RSS changes by threshold To: Joel Fernandes Cc: LKML , Tim Murray , Carmen Jackson , mayankgupta@google.com, Daniel Colascione , Steven Rostedt , Minchan Kim , Andrew Morton , kernel-team , "Aneesh Kumar K.V" , Dan Williams , Jerome Glisse , linux-mm , Matthew Wilcox , Michal Hocko , Ralph Campbell , Vlastimil Babka Content-Type: text/plain; charset="UTF-8" X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, Sep 3, 2019 at 10:02 PM Joel Fernandes wrote: > > On Tue, Sep 03, 2019 at 09:44:51PM -0700, Suren Baghdasaryan wrote: > > On Tue, Sep 3, 2019 at 1:09 PM Joel Fernandes (Google) > > wrote: > > > > > > Useful to track how RSS is changing per TGID to detect spikes in RSS and > > > memory hogs. 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 so I'm posting it upstream. > > > > > > 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) > > > > > > --- > > > > > > v1->v2: Added more commit message. > > > > > > 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 > > > > IIUC the counter has to change by 128 pages (512kB assuming 4kB pages) > > before the change gets traced. Would it make sense to make this step > > size configurable? For a system with limited memory size change of > > 512kB might be considerable while on systems with plenty of memory > > that might be negligible. Not even mentioning possible difference in > > page sizes. Maybe something like > > /sys/kernel/debug/tracing/rss_step_order with > > TRACE_MM_COUNTER_THRESHOLD=(1< > I would not want to complicate this more to be honest. It is already a bit > complex, and I am not sure about the win in making it as configurable as you > seem to want. The "threshold" thing is just a slight improvement, it is not > aiming to be optimal. If in your tracing, this granularity is an issue, we > can visit it then. I guess that can be done as a separate patch later on if necessary. > > thanks, > > - Joel > > > > > > +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 > > > > > > -- > > > To unsubscribe from this group and stop receiving emails from it, send an email to kernel-team+unsubscribe@android.com. > > > > > -- > To unsubscribe from this group and stop receiving emails from it, send an email to kernel-team+unsubscribe@android.com. >