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[173.79.60.52]) by smtp.gmail.com with ESMTPSA id d75a77b69052e-53080ce82aesm39676931cf.31.2026.09.07.15.27.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 07 Sep 2026 15:27:18 -0700 (PDT) Date: Mon, 7 Sep 2026 18:27:14 -0400 From: Gregory Price To: Oleg Nesterov Cc: Ye Liu , Thomas Gleixner , Peter Zijlstra , "Rafael J. Wysocki" , Andrew Morton , Ingo Molnar , Will Deacon , Boqun Feng , "Paul E. McKenney" , Frederic Weisbecker , Neeraj Upadhyay , Joel Fernandes , Josh Triplett , Uladzislau Rezki , Juri Lelli , Vincent Guittot , Steven Rostedt , Masami Hiramatsu , Josh Poimboeuf , Ye Liu , Michal Hocko , mic@digikod.net, david@kernel.org, linmiaohe@huawei.com, nao.horiguchi@gmail.com, gnoack3000@gmail.com, ljs@kernel.org, sj@kernel.org, rientjes@google.com, shakeel.butt@linux.dev, xu.xin16@zte.com.cn, chengming.zhou@linux.dev, tony.luck@intel.com, reinette.chatre@intel.com, x86@kernel.org, paul@paul-moore.com, jmorris@namei.org, serge@hallyn.com, pavel@kernel.org, lance.yang@linux.dev, pmladek@suse.com, longman@redhat.com, mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com, qiang.zhang@linux.dev, dietmar.eggemann@arm.com, bsegall@google.com, mgorman@suse.de, vschneid@redhat.com, kprateek.nayak@amd.com, mark.rutland@arm.com, Dave.Martin@arm.com, james.morse@arm.com, babu.moger@amd.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, rcu@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-security-module@vger.kernel.org Subject: Re: [PATCH v2 5/8] kernel: convert process/thread iterators to for_each_*_rculock Message-ID: References: <20260907081334.1152889-1-ye.liu@linux.dev> <20260907081334.1152889-6-ye.liu@linux.dev> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Stat-Signature: rqg74x1z4qb651nqpizit7g8m8f85qb3 X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 666ADC0003 X-Rspam-User: X-HE-Tag: 1788820039-425561 X-HE-Meta: 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 JSZbD+Hg jyxklcYeUWVoA1YWDRZ35sXDD9yMkq9bQK9kFNYDT9QFWpPOl0U44s8psvPBSt9sZeoTLxoVQP9hpXayKcn7g4RWNub41iIsgp8Vkg1B2iv7pidnW5Nly5KM3e/gkSzqVOA9L3g5nhjSw/pQZb6C2odACmovmf+iIyxkLVmuAax/+eZaVP6VXlFzLPKKBzGugpcQDnmXSAUKVWsOWZQWm5noEmKA/RIXDhFfzVeMycVExDy9kkmkyobVgGezEDf38iu0u5DqqztYoA9S7KjSsKPLRQsZpHS5LPot4X495MtsglSMEgoPG1JoGHa8Pt+BzJprGfy3clkRL3rOOJyI2DufjCSSkefNDDxtDrpSVhBQMI4P8+QyF2e5HBpyLPJKzUTPsEXMSIcSrcPKf3oNNyPduCVBEDm3A08UP7uOCp9ccM4uVRvqGHWqZ78fqDlnHxQ3j16KhiNYRa/I= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Mon, Sep 07, 2026 at 11:54:41PM +0200, Oleg Nesterov wrote: > > > > This might be my - admittedly shallow - understanding of scoped_guard, > > but does scoped guard handle goto correctly? > > Yes, it does, > > > and why it's generally discouraged to mix cleanup.h and goto. > > Hmm, why? I didn't know... > one of the reasons to use cleanup.h it is to eliminate the "goto for exit cleanup" mechanism in the first place (says so in the first paragraph of cleanup.h). Later in the header is explicit says don't mix: * Lastly, given that the benefit of cleanup helpers is removal of * "goto", and that the "goto" statement can jump between scopes, the * expectation is that usage of "goto" and cleanup helpers is never * mixed in the same function. I.e. for a given routine, convert all * resources that need a "goto" cleanup to scope-based cleanup, or * convert none of them. This particular patch only does a partial conversion - so it's a bit of an anti-pattern. Reading up on scoped_guard a bit more it seems you're right it handles the issue to jump-out, but i can see why cleanup.h says "don't do that" because it's confusing to look at / hard to reason about. ~Gregory