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[109.81.17.247]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-482fbb28492sm20835619f8f.31.2026.08.31.02.09.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 31 Aug 2026 02:09:41 -0700 (PDT) Date: Mon, 31 Aug 2026 11:09:40 +0200 From: Michal Hocko To: Andrew Morton Cc: Ye Liu , Ye Liu , David Rientjes , Shakeel Butt , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH] mm/oom_kill, proc: replace magic number 1000 with OOM_SCORE_ADJ_MAX Message-ID: References: <20260811033609.3992348-1-ye.liu@linux.dev> <20260829201310.648ed330984b91b1c135d8a3@linux-foundation.org> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260829201310.648ed330984b91b1c135d8a3@linux-foundation.org> On Sat 29-08-26 20:13:10, Andrew Morton wrote: > On Tue, 11 Aug 2026 11:36:08 +0800 Ye Liu wrote: > > > From: Ye Liu > > > > In oom_badness() and proc_oom_score(), the oom_score_adj normalization > > uses a hardcoded 1000, which is the value of OOM_SCORE_ADJ_MAX defined > > in include/uapi/linux/oom.h. Other code in the kernel (e.g. > > fs/proc/base.c oom_adj handling) already uses OOM_SCORE_ADJ_MAX for > > the same purpose. > > > > Replace the magic number with the macro for consistency and > > readability. No functional change. > > > > ... > > > > --- a/fs/proc/base.c > > +++ b/fs/proc/base.c > > @@ -594,7 +594,8 @@ static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns, > > * exporting for a long time so userspace might depend on it. > > */ > > if (badness != LONG_MIN) > > - points = (1000 + badness * 1000 / (long)totalpages) * 2 / 3; > > + points = (OOM_SCORE_ADJ_MAX + > > + badness * OOM_SCORE_ADJ_MAX / (long)totalpages) * 2 / 3; > > > > seq_printf(m, "%lu\n", points); > > > > diff --git a/mm/oom_kill.c b/mm/oom_kill.c > > index 5f372f6e26fa..08bff7a55db8 100644 > > --- a/mm/oom_kill.c > > +++ b/mm/oom_kill.c > > @@ -230,7 +230,7 @@ long oom_badness(struct task_struct *p, unsigned long totalpages) > > task_unlock(p); > > > > /* Normalize to oom_score_adj units */ > > - adj *= totalpages / 1000; > > + adj *= totalpages / OOM_SCORE_ADJ_MAX; > > points += adj; > > > > return points; > > AI review suggests that this is a misinterpretation of "1000"? > > https://sashiko.dev/#/patchset/20260811033609.3992348-1-ye.liu@linux.dev Sashiko is trying to be clever and it is simply wrong here. The scaling fact is indeed the same as the OOM_SCORE_ADJ_MAX. -- Michal Hocko SUSE Labs