Messages in this thread |  | | Date | Tue, 27 Nov 2001 12:31:28 -0800 | From | Mike Fedyk <> | Subject | Re: Unresponiveness of 2.4.16 |
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On Tue, Nov 27, 2001 at 09:12:13AM -0800, Andrew Morton wrote: > Ahmed Masud wrote: > > > > Just to add to the above something I've experienced: > > > > 2.4.12 - 2.4.14 on a number of AMD Athelon 900 with 256 MB > > RAM doing serial I/O would miss data while any DISK writes would > > occure. > > Two possibilities suggest themselves: > > - Interrupt latency. Last time I checked (a year ago), the worst-case > interrupt latency of the IDE drivers was 80 microseconds on a 500MHz PII. > That was with `hdparm -u 1'. That's pretty good. > > Could you please confirm that you're using `hdparm -u 1' against the > relevant disk? > > - The serial port is working OK, but the application which is handling > serial IO is blocked on a disk read (something got paged out), and > that disk read fails to complete by the time the serial port buffer > fills up. > > I'll send you a patch which makes the VM less inclined to page things > out in the presence of heavy writes, and which decreases read > latencies. > Is this patch posted anywhere? - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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