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Received: from willy by casper.infradead.org with local (Exim 4.98 #2 (Red Hat Linux)) id 1t12Ym-00000007pBy-0A88; Wed, 16 Oct 2024 11:51:24 +0000 Date: Wed, 16 Oct 2024 12:51:23 +0100 From: Matthew Wilcox To: Christoph Hellwig Cc: lizhe.67@bytedance.com, peterz@infradead.org, mingo@redhat.com, will@kernel.org, longman@redhat.com, boqun.feng@gmail.com, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [RFC 1/2] rwsem: introduce upgrade_read interface Message-ID: References: <20241016043600.35139-1-lizhe.67@bytedance.com> <20241016043600.35139-2-lizhe.67@bytedance.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Server: rspam03 X-Rspam-User: X-Rspamd-Queue-Id: 9A1AD1C0010 X-Stat-Signature: rni46ohj7de6pothwh5jiyrgn93zonx4 X-HE-Tag: 1729079478-102196 X-HE-Meta: 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 bM+PQZyo s37SN0Lm04nJ/em8EdtAnryFTX7A2+Q5h5m6U8L90vfc3c5jmedLHneg+gh+5qmBOnwxS1wXBapkTqEE+FYKIk7b0ApzvzB8MJ9PuEE0MxRCQPd8Zd/ms7SSeqHm4bQsLGEqEv84SndFuFj6AiWL2sEj6yEtXfhCcdSIWOzZ9pVS23i1ZhIhdAY9JBK3QKQojKb7Tb7axLL6CB/TdETsgWsFZIqUiSjA00me55q/mEKsYK0YhPu3lPdhg6VVEtUqAsb0pLSU4Yo4jUNrkpkDKuBl3qY9ovyKPt6dMbSr+Q52OjTRRQYbzui1RcMCWtLsId08bvqIjTJOAeHRxeKSCMCYRlGYQI0qMVSdrQ2lso58VzIoZr6LB08LP3Q== 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: List-Subscribe: List-Unsubscribe: On Tue, Oct 15, 2024 at 09:56:51PM -0700, Christoph Hellwig wrote: > On Wed, Oct 16, 2024 at 12:35:59PM +0800, lizhe.67@bytedance.com wrote: > > From: Li Zhe > > > > Introduce a new rwsem interface upgrade_read(). We can call it > > It's obviously a try_upgrade_read, right? Well, that's confusing. "try" usually means "don't sleep", and this sleeps. Maybe it shouldn't sleep; ie we make this fail if there's any other reader? It'll succeed less often, but it'll be easier to understand.