From mboxrd@z Thu Jan 1 00:00:00 1970 From: Date: Sat, 11 Sep 1999 15:46:01 +0000 Subject: Re: low-latency benchmarks: excellent results of RTC clock + SIGIO 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 Sat, 11 Sep 1999, Benno Senoner wrote: > Seems that under high disk I/O load, > (very seldom, about every 30-100secs) the process > gets woken up one IRQ period later. > Ideas why this happens. this could be a lost RTC IRQ. If you are using 2048 Hz RTC interrupts, it just needs a single 1msec IRQ delay to lose an RTC IRQ. Especially SCSI disk interrupts are known to sometimes cause 1-2 millisecs IRQ delays. But before jumping to conclusions, what exactly are the symptoms, what does 'one IRQ period later' mean exactly? -- mingo