From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jaroslav Kysela Date: Thu, 26 Aug 1999 20:51:18 +0000 Subject: Re: Bad MIDI performance : 10ms latency instead of the expected Message-Id: List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-sound@vger.kernel.org On Thu, 26 Aug 1999, Alan Cox wrote: > > > 200bytes/sec is just rudiculous , how do you plan to drive an external synth > > > with that little MIDI bandwidth ? > > > > I need a timer around 2000Hz for some good code. I won't support polling > > mode (busy loop) in any case. > > Then your code will never be usable. Some hardware sucks, you have to do > limited polling with a timer backoff. A well tuned polling loop will often > work out nicely providing you are careful. Remember with irqs on you are > just like busy in userspace no worse. You can even do > > while(poll_input()=0) > { > if(current->need_resched()) > schedule(); > } > > sort of stuff Is possible to create some thread for this loop inside kernel module? I don't want to suspend the application execution due to a broken hardware. I did some tests with 2.2 kernels (using kernel_thread()) and I've not been successful. Jaroslav ----- Jaroslav Kysela SuSE Linux http://www.suse.com ALSA project http://www.alsa-project.org