From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ravikiran G Thirumalai Subject: Re: [patch 1/4] net: percpufy frequently used vars -- add percpu_counter_mod_bh Date: Wed, 8 Mar 2006 16:18:03 -0800 Message-ID: <20060309001803.GF4493@localhost.localdomain> References: <20060308015808.GA9062@localhost.localdomain> <20060308015934.GB9062@localhost.localdomain> <20060307181301.4dd6aa96.akpm@osdl.org> <20060308202656.GA4493@localhost.localdomain> <20060308203642.GZ5410@kvack.org> <20060308210726.GD4493@localhost.localdomain> <20060308211733.GA5410@kvack.org> <20060308222528.GE4493@localhost.localdomain> <20060308224140.GC5410@kvack.org> <20060308154321.0e779111.akpm@osdl.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Benjamin LaHaise , linux-kernel@vger.kernel.org, davem@davemloft.net, netdev@vger.kernel.org, shai@scalex86.org Return-path: To: Andrew Morton Content-Disposition: inline In-Reply-To: <20060308154321.0e779111.akpm@osdl.org> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Wed, Mar 08, 2006 at 03:43:21PM -0800, Andrew Morton wrote: > Benjamin LaHaise wrote: > > > > I think it may make more sense to simply convert local_t into a long, given > > that most of the users will be things like stats counters. > > > > Yes, I agree that making local_t signed would be better. It's consistent > with atomic_t, atomic64_t and atomic_long_t and it's a bit more flexible. > > Perhaps. A lot of applications would just be upcounters for statistics, > where unsigned is desired. But I think the consistency argument wins out. It already is... for most of the arches except x86_64. And on -mm, the asm-generic version uses atomic_long_t for local_t (signed long) which seems right. Although, I wonder why we use: #define local_read(l) ((unsigned long)atomic_long_read(&(l)->a)) It would return a huge value if the local counter was even -1 no?