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Date:   Wed, 4 Sep 2019 01:15:49 -0400
From:   Joel Fernandes <joel@joelfernandes.org>
To:     Daniel Colascione <dancol@google.com>
Cc:     Suren Baghdasaryan <surenb@google.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Tim Murray <timmurray@google.com>,
        Carmen Jackson <carmenjackson@google.com>,
        Mayank Gupta <mayankgupta@google.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Minchan Kim <minchan@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        kernel-team <kernel-team@android.com>,
        "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>,
        Dan Williams <dan.j.williams@intel.com>,
        Jerome Glisse <jglisse@redhat.com>,
        linux-mm <linux-mm@kvack.org>,
        Matthew Wilcox <willy@infradead.org>,
        Michal Hocko <mhocko@suse.cz>,
        Ralph Campbell <rcampbell@nvidia.com>,
        Vlastimil Babka <vbabka@suse.cz>
Subject: Re: [PATCH v2] mm: emit tracepoint when RSS changes by threshold
Message-ID: <20190904051549.GB256568@google.com>
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On Tue, Sep 03, 2019 at 09:51:20PM -0700, Daniel Colascione wrote:
> On Tue, Sep 3, 2019 at 9:45 PM Suren Baghdasaryan <surenb@google.com> wrote:
> >
> > On Tue, Sep 3, 2019 at 1:09 PM Joel Fernandes (Google)
> > <joel@joelfernandes.org> 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.
> 
> It's also worth being able to turn off the per-task memory counter
> caching, otherwise you'll have two levels of batching before the
> counter gets updated, IIUC.

I prefer to keep split RSS accounting turned on if it is available. I think
discussing split RSS accounting is a bit out of scope of this patch as well.
Any improvements on that front can be a follow-up.

Curious, has split RSS accounting shown you any issue with this patch?

thanks,

 - Joel