Received-SPF: pass (google.com: domain of linux-kernel+bounces-65360-linux.lists.archive=gmail.com@vger.kernel.org designates 139.178.88.99 as permitted sender) client-ip=139.178.88.99;
Date: Wed, 14 Feb 2024 15:46:33 +0100
From: Michal Hocko <mhocko@suse.com>
To: Johannes Weiner <hannes@cmpxchg.org>
Cc: Suren Baghdasaryan <surenb@google.com>, akpm@linux-foundation.org,
	kent.overstreet@linux.dev, vbabka@suse.cz, roman.gushchin@linux.dev,
	mgorman@suse.de, dave@stgolabs.net, willy@infradead.org,
	liam.howlett@oracle.com, corbet@lwn.net, void@manifault.com,
	peterz@infradead.org, juri.lelli@redhat.com,
	catalin.marinas@arm.com, will@kernel.org, arnd@arndb.de,
	tglx@linutronix.de, mingo@redhat.com, dave.hansen@linux.intel.com,
	x86@kernel.org, peterx@redhat.com, david@redhat.com,
	axboe@kernel.dk, mcgrof@kernel.org, masahiroy@kernel.org,
	nathan@kernel.org, dennis@kernel.org, tj@kernel.org,
	muchun.song@linux.dev, rppt@kernel.org, paulmck@kernel.org,
	pasha.tatashin@soleen.com, yosryahmed@google.com, yuzhao@google.com,
	dhowells@redhat.com, hughd@google.com, andreyknvl@gmail.com,
	keescook@chromium.org, ndesaulniers@google.com, vvvvvv@google.com,
	gregkh@linuxfoundation.org, ebiggers@google.com, ytcoode@gmail.com,
	vincent.guittot@linaro.org, dietmar.eggemann@arm.com,
	rostedt@goodmis.org, bsegall@google.com, bristot@redhat.com,
	vschneid@redhat.com, cl@linux.com, penberg@kernel.org,
	iamjoonsoo.kim@lge.com, 42.hyeyoo@gmail.com, glider@google.com,
	elver@google.com, dvyukov@google.com, shakeelb@google.com,
	songmuchun@bytedance.com, jbaron@akamai.com, rientjes@google.com,
	minchan@google.com, kaleshsingh@google.com, kernel-team@android.com,
	linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
	iommu@lists.linux.dev, linux-arch@vger.kernel.org,
	linux-fsdevel@vger.kernel.org, linux-mm@kvack.org,
	linux-modules@vger.kernel.org, kasan-dev@googlegroups.com,
	cgroups@vger.kernel.org
Subject: Re: [PATCH v3 00/35] Memory allocation profiling
Message-ID: <ZczSSZOWMlqfvDg8@tiehlicka>
References: <20240212213922.783301-1-surenb@google.com>
 <20240214062020.GA989328@cmpxchg.org>
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20240214062020.GA989328@cmpxchg.org>

On Wed 14-02-24 01:20:20, Johannes Weiner wrote:
[...]
> I agree we should discuss how the annotations are implemented on a
> technical basis, but my take is that we need something like this.

I do not think there is any disagreement on usefulness of a better
memory allocation tracking. At least for me the primary problem is the
implementation. At LFSMM last year we have heard that existing tracing
infrastructure hasn't really been explored much. Cover letter doesn't
really talk much about those alternatives so it is really hard to
evaluate whether the proposed solution is indeed our best way to
approach this.

> In a codebase of our size, I don't think the allocator should be
> handing out memory without some basic implied tracking of where it's
> going. It's a liability for production environments, and it can hide
> bad memory management decisions in drivers and other subsystems for a
> very long time.

Fully agreed! It is quite common to see oom reports with a large portion
of memory unaccounted and this really presents additional cost on the
debugging side.

-- 
Michal Hocko
SUSE Labs