Messages in this thread | | | Date | Fri, 25 Jul 1997 03:19:07 +0100 (WET DST) | From | "Manuel J. Galan" <> | Subject | Re: 2.0.30 serial.c, ppp.c and pppd-2.2 questions |
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Hi,
Well I am runnung 2.1.4[67] with a startech 16c650 serial connected to a Zyxel ISDN TA (Omni Ta 128) at 460800 baud against a CISCO 2500 IOS 11.2(3)
When there is only one line (64Kb + stac compression) everything goes more or less OK but when both lines join in a Multilink PPP connection ppp chokes and transference stops for a while, then restarts and stops again and so on. The result is that I get ~ 7 Kbyte/s whith two lines joined in a large compressed file transfer... Not very good, mostly because I get almost the same speed (or even better) using only one line.
Thansferring normal files, it is a real pity as the stac compression could make transfer speed reach 50-55 Kbyte/s (as it does in M$ NT4) and I only can get 8-10 KB/s under Linux.
My hardware is a tyan dual ppro with two cpu at 200Mhz, _no ide_, bt-958 scsi + scsi disks. only one serial active and ps/2 mouse.
Irqtune makes no difference. I have tried ppp 2.2.0, 2.3.0 and 2.3.1 at no avail...
The thing that drives me mad is that NT4 _does_ work OK.
On 25-Jul-97 Andries.Brouwer@cwi.nl wrote: >Theodore Y. Ts'o: > >: Date: Thu, 24 Jul 1997 00:06:25 +0200 >: From: Andries.Brouwer@cwi.nl > >: Possibly entirely unrelated (you are talking about missed timer >interrupts, >: probably I am talking about missed serial line interrupts) but >: my SLIP connection is completely unusable when something disk-intensive >: is running. FTP gets into an exponential backoff and seems to hang >: completely, but recovers some time after the make/find/whatever has >: finished. > >: [This happens both with IDE and SCSI activity. I never really >: investigated.] > >: At least for the IDE case, this is the very well known problem of the >: IDE driver disabling interrupts to prevent data corruption in a few >: badl;y designed IDE controllers. If you don't have the bad IDE >: controllers (see the man page for more details), you will likely be able >: to use "hdarm -u 1" which will fix the problem without causing your >: disks to get massively corruption. > >: As far as the SCSI activity, my guess it is a similar problem, but the >: solution to solve it is very dependent on the SCSI manufacturer. > >: - Ted > >You are an optimist. >(On the one hand "hdparm -u 1" does cause corruption here, >on the other hand, it doesnt help at all.) > >Suppose something is wrong in the scheduler, and processes >with finished disk I/O get too much attention. >I just showed my son how an e2fsck on a large SCSI disk really >stopped all other activity. > >Andries > > - --- Manuel J. Galan manolow@step.es
Sent on 25-Jul-97 03:37:15
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