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Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: <20230130103343.GA11663@lst.de> References: <20230130103343.GA11663@lst.de> <20230130092157.1759539-21-hch@lst.de> <20230130092157.1759539-1-hch@lst.de> <3347459.1675074683@warthog.procyon.org.uk> To: Christoph Hellwig Cc: dhowells@redhat.com, linux-block@vger.kernel.org, ceph-devel@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-nvme@lists.infradead.org, linux-scsi@vger.kernel.org, target-devel@vger.kernel.org, kvm@vger.kernel.org, netdev@vger.kernel.org, linux-afs@lists.infradead.org, linux-cifs@vger.kernel.org, samba-technical@lists.samba.org, linux-fsdevel@vger.kernel.org, linux-nfs@vger.kernel.org, devel@lists.orangefs.org, io-uring@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 20/23] rxrpc: use bvec_set_page to initialize a bvec MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <3351917.1675077855.1@warthog.procyon.org.uk> Date: Mon, 30 Jan 2023 11:24:15 +0000 Message-ID: <3351918.1675077855@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 3.1 on 10.11.54.9 X-Rspam-User: X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: E9DC44000F X-Stat-Signature: wrneab6c38ypdfsqegitnhkd58ywq6yo X-HE-Tag: 1675077866-936979 X-HE-Meta: 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 8wGNic6U +Ym2mBsAJ5V3SjCxbSMztXYzKe9rzudIUwuILNH4neS5txkT2My3TI+NSNoMqAgguOoro3M8WTwsw1w4cgMIiqC4ZIUzKKBdPAVji4bCFncLDB1aQSv8AQoIxVr1QyVP3bIDLYR2qY/gM1PP9adp8ZOxSonm16/4elgCthCT1muQn0tIAa2Q9WGH6EtwWrzVCy5ljBOYx7Hkyj+KXYu5CflssiSrx0LfmoT+y 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: Christoph Hellwig wrote: > On Mon, Jan 30, 2023 at 10:31:23AM +0000, David Howells wrote: > > Christoph Hellwig wrote: > > > > > + bvec_set_page(&bv, ZERO_PAGE(0), len, 0); > > > > Maybe bvec_set_zero_page()? > > Why? Seems to be something people want to do quite a lot and don't know about. I've seen places where someone allocates a buffer and clears it just to use as a source of zeros. There's at least one place in cifs, for example. I know about it from wrangling arch code, but most people working on Linux haven't done that. David