Date: Sun, 2 Jul 1995 02:10:02 -0700 From: Heikki Suonsivu <hsu@clinet.fi> To: freebsd-bugs Subject: kern/579: sio: RS_IBUFSIZE 256 too small Message-ID: <199507020910.CAA22709@freefall.cdrom.com> In-Reply-To: Your message of Sun, 2 Jul 1995 12:00:36 %2B0300 <199507020900.MAA01179@katiska.clinet.fi>
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>Number: 579 >Category: kern >Synopsis: sio: RS_IBUFSIZE at 256 bytes serial lines loose data (PPP) >Confidential: no >Severity: serious >Priority: high >Responsible: freebsd-bugs (FreeBSD bugs mailing list) >State: open >Class: change-request >Submitter-Id: current-users >Arrival-Date: Sun Jul 2 02:10:00 1995 >Originator: Heikki Suonsivu >Organization: Clinet, Espoo, Finland >Release: FreeBSD 2.0-BUILT-19950507 i386 >Environment: A 486-40 with 6 16550 ports and 4 ethernets (3 active) A 386-16 with 1 16550 ports and 1 ethernet (just a PPP router) >Description: Both these machines report "interrupt-level buffer overflow":s very frequently on a leased line running at 38400, badly dropping IP performance. On 386-16 I also saw several spontaneous reboots when loading the PPP link. >How-To-Repeat: It seems that this bites only me, even though it does this on two quite different configurations. In addition the 486 machine has 115.2k leased line connected with no apparent trouble. Thus I can't really tell you how to repeat this (other than sending the machines there :-). >Fix: I changed RS_IBUFSIZE from 256 to 4096, and the problem disappeared. It might be that a smaller amount would be sufficient (I don't mind 8k memory waste per line in this case). But it is apparent that 256 bytes seems not sufficient for slow or loaded machines. sio.c: < #define RS_IBUFSIZE 256 -- > #define RS_IBUFSIZE 4096 >Audit-Trail: >Unformatted:
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