> From: Oliver Neukum > Newsgroups: gmane.linux.usb.devel > Subject: Re: CDC-ACM driver: data duplication due to throttling > Date: Tue, 6 Feb 2007 11:38:09 +0100
Hallo. > To: [] > Am Dienstag, 6. Februar 2007 10:38 schrieb Joris van Rantwijk: >> On 5 feb 2007, at 23:07, Alan wrote: >> > atomic_t on many platforms isn't that efficient and there are more >> > cases >> > where the atomic bit operations are fast. How about using >> > test_bit/set_bit/clear_bit/etc >> >> I don't know. The thing is, I want something different from atomicity. >> >> In itself, atomically setting a variable to a value is not a very >> impressive achievement. This is different for bit operations, but I'm >> not interested in bit operations at all. >> >>What I really want is ordered access and volatility. I want exactly the >>kind of semantics that Java defines for volatile variables. > > A spinlock will surely do that. For the time being I'll push your first > three patches forward and we can discuss this particular issue later. Really? I think, better to try smp_mb__after_clear_bit() with friends. And 'volatile' in C have nothing to do with hardware: SMP, caches or whatever there may be. Search more on that in lkml archives. ____ ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier. Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
