From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Subject: Re: [RFC PATCH for 4.17 02/21] rseq: Introduce restartable sequences system call (v12) Date: Wed, 28 Mar 2018 14:52:16 +0200 Message-ID: <20180328125216.GF4129@hirez.programming.kicks-ass.net> References: <20180327160542.28457-1-mathieu.desnoyers@efficios.com> <20180327160542.28457-3-mathieu.desnoyers@efficios.com> <20180328122946.GU4043@hirez.programming.kicks-ass.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20180328122946.GU4043@hirez.programming.kicks-ass.net> Sender: linux-kernel-owner@vger.kernel.org To: Mathieu Desnoyers Cc: "Paul E . McKenney" , Boqun Feng , Andy Lutomirski , Dave Watson , linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, Paul Turner , Andrew Morton , Russell King , Thomas Gleixner , Ingo Molnar , "H . Peter Anvin" , Andrew Hunter , Andi Kleen , Chris Lameter , Ben Maurer , Steven Rostedt , Josh Triplett , Linus Torvalds , Catalin Marinas , Will Deacon List-Id: linux-api@vger.kernel.org On Wed, Mar 28, 2018 at 02:29:46PM +0200, Peter Zijlstra wrote: > > +static int rseq_get_rseq_cs(struct task_struct *t, > > + unsigned long *start_ip, > > + unsigned long *post_commit_offset, > > + unsigned long *abort_ip, > > + uint32_t *cs_flags) > > +{ > > > + > > + *cs_flags = rseq_cs.flags; > > + *start_ip = rseq_cs.start_ip; > > + *post_commit_offset = rseq_cs.post_commit_offset; > > + *abort_ip = rseq_cs.abort_ip; > > Then this becomes a straight struct assignment. I initially suggested passing a structure instead of many arguments, but then recondidered, mostly because it will be inlined (due to having only the one caller) anyway. Still, maybe a struct will work better, I dunno. 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McKenney" , Boqun Feng , Andy Lutomirski , Dave Watson , linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, Paul Turner , Andrew Morton , Russell King , Thomas Gleixner , Ingo Molnar , "H . Peter Anvin" , Andrew Hunter , Andi Kleen , Chris Lameter , Ben Maurer , Steven Rostedt , Josh Triplett , Linus Torvalds , Catalin Marinas , Will Deacon , Michael Kerrisk , Alexander Viro Subject: Re: [RFC PATCH for 4.17 02/21] rseq: Introduce restartable sequences system call (v12) Message-ID: <20180328125216.GF4129@hirez.programming.kicks-ass.net> References: <20180327160542.28457-1-mathieu.desnoyers@efficios.com> <20180327160542.28457-3-mathieu.desnoyers@efficios.com> <20180328122946.GU4043@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180328122946.GU4043@hirez.programming.kicks-ass.net> User-Agent: Mutt/1.9.3 (2018-01-21) Sender: linux-api-owner@vger.kernel.org X-Mailing-List: linux-api@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On Wed, Mar 28, 2018 at 02:29:46PM +0200, Peter Zijlstra wrote: > > +static int rseq_get_rseq_cs(struct task_struct *t, > > + unsigned long *start_ip, > > + unsigned long *post_commit_offset, > > + unsigned long *abort_ip, > > + uint32_t *cs_flags) > > +{ > > > + > > + *cs_flags = rseq_cs.flags; > > + *start_ip = rseq_cs.start_ip; > > + *post_commit_offset = rseq_cs.post_commit_offset; > > + *abort_ip = rseq_cs.abort_ip; > > Then this becomes a straight struct assignment. I initially suggested passing a structure instead of many arguments, but then recondidered, mostly because it will be inlined (due to having only the one caller) anyway. Still, maybe a struct will work better, I dunno.