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Shenoy" , Rasmus Villemoes , Neeraj.Upadhyay@amd.com, Ananth.narayan@amd.com, Swapnil Sapkal Subject: Re: [RFC PATCH 3/3] treewide: pipe: Convert all references to pipe->{head,tail,max_usage,ring_size} to unsigned short Message-ID: <20250306124120.GF19868@redhat.com> References: <20250306113924.20004-1-kprateek.nayak@amd.com> <20250306113924.20004-4-kprateek.nayak@amd.com> <20250306123245.GE19868@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250306123245.GE19868@redhat.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 X-Rspam-User: X-Rspamd-Queue-Id: 16C6714000D X-Rspamd-Server: rspam09 X-Stat-Signature: 8w89ruktry798z9p3sak76nstei555qy X-HE-Tag: 1741264926-551403 X-HE-Meta: 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 FW2PEWEk lvCXweh0usxfAoIJ1c6h5Gv6qZhMg/BNp5zvnYbdeMjVSkypd536JoGoM+CckypnHxkYa3CSuX23848PlGtYjnR3MaAAVRIJ6lHM1Ppi41kiI6tBz8t9H+VaRqmWaHJusRaMNM7HA6HyZSVXENHNmQdWu8buMg3dvoipwV3qyWb+Cnyi005C3Npnp4rQfIMxo7CqZ7bOM4ny0Velpkjiqdgqr6K3QALrfOCPM4wGtKogMiFW0SCsmErkVv16DoOB+IPiGjP3qajdYxtb8E0n6bVJWbufREXh/gXUm1mg5wWQoLYtahkD/6Smk7ZqsMD+fIVci 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 03/06, Oleg Nesterov wrote: > > On 03/06, K Prateek Nayak wrote: > > > > @@ -272,9 +272,9 @@ pipe_read(struct kiocb *iocb, struct iov_iter *to) > > */ > > for (;;) { > > /* Read ->head with a barrier vs post_one_notification() */ > > - unsigned int head = smp_load_acquire(&pipe->head); > > - unsigned int tail = pipe->tail; > > - unsigned int mask = pipe->ring_size - 1; > > + unsigned short head = smp_load_acquire(&pipe->head); > > + unsigned short tail = pipe->tail; > > + unsigned short mask = pipe->ring_size - 1; > > I dunno... but if we do this, perhaps we should > s/unsigned int/pipe_index_t instead? > > At least this would be more grep friendly. in any case, I think another cleanup before this change makes sense... pipe->ring_size is overused. pipe_read(), pipe_write() and much more users do not need "unsigned int mask", they can use pipe_buf(buf, slot) instead. Oleg.