Date: Fri, 08 Jan 1999 15:13:19 +0800 From: Kow Kee Nge <kowkn@asia1.com.sg> To: Heikki Suonsivu <hsu@clinet.fi> Cc: freebsd-bugs@FreeBSD.ORG Subject: Re: i386/9341: tty-level buffer overflows Message-ID: <199901080711.PAA22618@terra.post1.com> In-Reply-To: <x2btkc7acq.fsf@katiska.clinet.fi> References: <kowkn@asia1.com.sg's message of 6 Jan 1999 07:39:24 %2B0200> <199901060451.UAA12400@hub.freebsd.org.newsgate.clinet.fi>
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Hi Heikki Suonsivu, I followed your instruction with "TTYHOG=4096" and RS_IBUFSIZE=1024 tuned into the kernel. There seems to have some improvement. However when I set RS_IBUFSIZE=3072, the improvment is noticeable with the overflow getting much less eventhough I wish I can totally eliminate it. My question is can I set options "TTYHOG=8192" options "RS_IBUFSIZE=4096" # or may higher but less than 8192 ? Your assistance is much appreciate. Regards At 16:19 06/01/99 +0200, Heikki Suonsivu wrote: > >These > >options "TTYHOG=4096" >options "RS_IBUFSIZE=1024" > >Seems to do the trick for me. I think in addition you need to add this >patch to sio.c to allow configuring from kernel config files: > >Index: sio.c >=================================================================== >RCS file: /usr/CVS/src/sys/i386/isa/sio.c,v >retrieving revision 1.147.2.16 >diff -c -r1.147.2.16 sio.c >*** sio.c 1998/06/16 12:51:17 1.147.2.16 >--- sio.c 1998/06/30 08:40:08 >*************** >*** 100,106 **** >--- 100,113 ---- > > #define LOTS_OF_EVENTS 64 /* helps separate urgent events from input */ > #define RB_I_HIGH_WATER (TTYHOG - 2 * RS_IBUFSIZE) >+ >+ #ifndef RS_IBUFSIZE >+ #ifndef DPTOPT /* not sure why this is in dpt.. latency requirements? [JRE] */ > #define RS_IBUFSIZE 256 >+ #else >+ #define RS_IBUFSIZE 512 >+ #endif /* DPTOPT */ >+ #endif /* !RS_IBUFSIZE */ > > #define CALLOUT_MASK 0x80 > #define CONTROL_MASK 0x60 > >I do not understand why these values have stuck to be too small for ages, >as most older hardware need this to be able to reliable communicate at >higher speeds. > >I also tried at some point using RS_IBUFSIZE=4096 and not tuning TTYHOG, >which did work fine for kernel PPP while without the connection was >unreliable. However I think some comments say that evil things may happen >for flow control if RS_IBUFSIZE is larger or equal to TTYHOG. > >kowkn@asia1.com.sg writes: > >> >Synopsis: tty-level buffer overflows >... >> Jan 5 16:22:13 lewis /kernel: sio0: 646 more tty-level buffer overflows (total 24 >> 16) >... >> >> What system parameters should we tune to increate the tty-level >> buffer? > >-- >Heikki Suonsivu / Clinet Oy / Tekniikantie 12 / FI-02150 Espoo / FINLAND, >hsu@clinet.fi mobile +358-40-5519679 work +358-9-43542270 fax -4555276 > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-bugs" in the body of the message
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