Date: Fri, 8 Sep 2000 18:05:18 +1100 (EST) From: Bruce Evans <bde@zeta.org.au> To: Warner Losh <imp@village.org> Cc: The Hermit Hacker <scrappy@hub.org>, freebsd-current@FreeBSD.ORG, freebsd-smp@FreeBSD.ORG Subject: Re: 'interrupt-level buffer overflows' for sio device? Message-ID: <Pine.BSF.4.21.0009081751460.30818-100000@besplex.bde.org> In-Reply-To: <200009080302.VAA50459@harmony.village.org>
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On Thu, 7 Sep 2000, Warner Losh wrote: > Also, this is interrupt level overflows. We can run the fast > interrupts fast enough to harvest characters from the hardware. > What's not happening is that sio's bottom half isn't being run fast > enough so the interrupt level buffers overflow. Not surprising, since sio's bottom half scheduler (schedsofttty()) is now null. The top half apparently only gets scheduled if there is an output interrupt, a fake output interrupt (flags 0x8) a modem status change, or urgent data. Urgent data probably keeps it going for slip and pppd, but there is no urgent data in the termios line discipline. Bruce To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-smp" in the body of the message
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