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Date:   Sun, 4 Nov 2018 11:16:12 +0200
From:   Mike Rapoport <rppt@linux.ibm.com>
To:     Sasha Levin <sashal@kernel.org>
Cc:     Dexuan Cui <decui@microsoft.com>, Roman Gushchin <guro@fb.com>,
        "linux-mm@kvack.org" <linux-mm@kvack.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Kernel Team <Kernel-team@fb.com>,
        Shakeel Butt <shakeelb@google.com>,
        Michal Hocko <mhocko@kernel.org>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Tejun Heo <tj@kernel.org>, Rik van Riel <riel@surriel.com>,
        Konstantin Khlebnikov <koct9i@gmail.com>,
        Matthew Wilcox <willy@infradead.org>,
        "Stable@vger.kernel.org" <Stable@vger.kernel.org>
Subject: Re: Will the recent memory leak fixes be backported to longterm
 kernels?
References: <PU1P153MB0169CB6382E0F047579D111DBFCF0@PU1P153MB0169.APCP153.PROD.OUTLOOK.COM>
 <20181102005816.GA10297@tower.DHCP.thefacebook.com>
 <PU1P153MB0169FE681EF81BCE81B005A1BFCF0@PU1P153MB0169.APCP153.PROD.OUTLOOK.COM>
 <20181102160122.GH194472@sasha-vm>
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On Fri, Nov 02, 2018 at 12:01:22PM -0400, Sasha Levin wrote:
> On Fri, Nov 02, 2018 at 02:45:42AM +0000, Dexuan Cui wrote:
> >>From: Roman Gushchin <guro@fb.com>
> >>Sent: Thursday, November 1, 2018 17:58
> >>
> >>On Fri, Nov 02, 2018 at 12:16:02AM +0000, Dexuan Cui wrote:
> >>Hello, Dexuan!
> >>
> >>A couple of issues has been revealed recently, here are fixes
> >>(hashes are from the next tree):
> >>
> >>5f4b04528b5f mm: don't reclaim inodes with many attached pages
> >>5a03b371ad6a mm: handle no memcg case in memcg_kmem_charge()
> >>properly
> >>
> >>These two patches should be added to the serie.
> >
> >Thanks for the new info!
> >
> >>Re stable backporting, I'd really wait for some time. Memory reclaim is a
> >>quite complex and fragile area, so even if patches are correct by themselves,
> >>they can easily cause a regression by revealing some other issues (as it was
> >>with the inode reclaim case).
> >
> >I totally agree. I'm now just wondering if there is any temporary workaround,
> >even if that means we have to run the kernel with some features disabled or
> >with a suboptimal performance?
> 
> I'm not sure what workload you're seeing it on, but if you could merge
> these 7 patches and see that it solves the problem you're seeing and
> doesn't cause any regressions it'll be a useful test for the rest of us.

AFAIK, with Roman's patches backported to Ubuntu version of 4.15, the
problem reported at [1] is solved.

[1] https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1792349
 
> --
> Thanks,
> Sasha
> 

-- 
Sincerely yours,
Mike.