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[73.93.239.127]) by smtp.gmail.com with ESMTPSA id c6sm396906pgl.38.2020.12.02.10.27.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 02 Dec 2020 10:27:44 -0800 (PST) From: Yang Shi To: guro@fb.com, ktkhai@virtuozzo.com, shakeelb@google.com, david@fromorbit.com, hannes@cmpxchg.org, mhocko@suse.com, akpm@linux-foundation.org Cc: shy828301@gmail.com, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 1/9] mm: vmscan: simplify nr_deferred update code Date: Wed, 2 Dec 2020 10:27:17 -0800 Message-Id: <20201202182725.265020-2-shy828301@gmail.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20201202182725.265020-1-shy828301@gmail.com> References: <20201202182725.265020-1-shy828301@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable 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: Currently if (next_deferred - scanned) =3D 0, the code would just read th= e current nr_deferred otherwise add the delta back. Both needs atomic operation an= yway, it seems there is not too much gain by distinguishing the two cases, so just= add the delta back even though the delta is 0. This would simply the code for th= e following patches too. Signed-off-by: Yang Shi --- mm/vmscan.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 7b4e31eac2cf..7d6186a07daf 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -528,14 +528,10 @@ static unsigned long do_shrink_slab(struct shrink_c= ontrol *shrinkctl, next_deferred =3D 0; /* * move the unused scan count back into the shrinker in a - * manner that handles concurrent updates. If we exhausted the - * scan, there is no need to do an update. + * manner that handles concurrent updates. */ - if (next_deferred > 0) - new_nr =3D atomic_long_add_return(next_deferred, - &shrinker->nr_deferred[nid]); - else - new_nr =3D atomic_long_read(&shrinker->nr_deferred[nid]); + new_nr =3D atomic_long_add_return(next_deferred, + &shrinker->nr_deferred[nid]); =20 trace_mm_shrink_slab_end(shrinker, nid, freed, nr, new_nr, total_scan); return freed; --=20 2.26.2