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Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1pnW14-009Iav-RJ; Sat, 15 Apr 2023 02:51:54 +0000 Date: Sat, 15 Apr 2023 03:51:54 +0100 From: Matthew Wilcox To: SeongJae Park Cc: akpm@linux-foundation.org, vbabka@suse.cz, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] mm/slab: break up RCU readers on SLAB_TYPESAFE_BY_RCU example code Message-ID: References: <20230415003754.1852-1-sj@kernel.org> <20230415003754.1852-3-sj@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230415003754.1852-3-sj@kernel.org> X-Rspam-User: X-Rspamd-Server: rspam03 X-Stat-Signature: brk7dci9zmc7xarsnioocerhxbmf6osa X-Rspamd-Queue-Id: A7D1B2000A X-HE-Tag: 1681527120-157130 X-HE-Meta: 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 Ve1oA+DM O593MbQeKgEZmpB1rSLNNyLwOS9zWM5vviHkJrReKl24Vp8iRCYsr9tkeZ1C2uaf7hC/2hkfhqLpbngt8zldCxUScUc6NMKq7d8yMwWae/uXkgVowgckC+nMiPlBsreJXtryQQKSQXGD6e282VNYQ7y2ud9tuSCe8aIi5ZeHsYaTMoRAUQDl6VHOwb7oZ0PjdBHYQtS53yHmG+gw= 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: On Sat, Apr 15, 2023 at 12:37:53AM +0000, SeongJae Park wrote: > * > + * begin: > * rcu_read_lock(); > - * again: > * obj = lockless_lookup(key); > * if (obj) { > * if (!try_get_ref(obj)) // might fail for free objects > - * goto again; > + * goto begin; > * > * if (obj->key != key) { // not the object we expected > * put_ref(obj); > + * rcu_read_unlock(); > * goto again; - * goto again; + * goto begin;