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From:   Qian Cai <cai@lca.pw>
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Subject: Re: [mm] 4e2c82a409: ltp.overcommit_memory01.fail
Date:   Sun, 5 Jul 2020 08:15:03 -0400
Message-Id: <FAAE2B23-2565-4F36-B278-018A5AD219EE@lca.pw>
References: <20200705044454.GA90533@shbuild999.sh.intel.com>
Cc:     kernel test robot <rong.a.chen@intel.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Michal Hocko <mhocko@suse.com>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Matthew Wilcox <willy@infradead.org>,
        Mel Gorman <mgorman@suse.de>,
        Kees Cook <keescook@chromium.org>,
        Luis Chamberlain <mcgrof@kernel.org>,
        Iurii Zaikin <yzaikin@google.com>, andi.kleen@intel.com,
        tim.c.chen@intel.com, dave.hansen@intel.com, ying.huang@intel.com,
        linux-mm@kvack.org, linux-kernel@vger.kernel.org, lkp@lists.01.org
In-Reply-To: <20200705044454.GA90533@shbuild999.sh.intel.com>
To:     Feng Tang <feng.tang@intel.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk


> On Jul 5, 2020, at 12:45 AM, Feng Tang <feng.tang@intel.com> wrote:
>=20
> I did reproduce the problem, and from the debugging, this should
> be the same root cause as lore.kernel.org/lkml/20200526181459.GD991@lca.pw=
/
> that loosing the batch cause some accuracy problem, and the solution of
> adding some sync is still needed, which is dicussed in

Well, before taking any of those patches now to fix the regression, we will n=
eed some performance data first. If it turned out the original performance g=
ain is no longer relevant anymore due to this regression fix on top, it is b=
est to drop this patchset and restore that VM_WARN_ONCE, so you can retry la=
ter once you found a better way to optimize.=