Re: 2.0.6 Networking strangeness
Mon, 15 Jul 1996 16:44:03 -0700

Date: Sun, 14 Jul 1996 13:37:22 +0300 (EET DST)
From: Linus Torvalds <>

However, this behaviour makes me suspect more and more that there is
something broken in the PPP (or serial code) timings,

Well, there is a known problem in the tty layer, which is that upper
layer processing doesn't happen except on the next clock tick. Hence,
there is on average a .005 second delay between when the PPP framing
character comes in and when it actually gets processed.

I've considered putting in a PPP specific hack where when the serial
layer sees the PPP framing character, it immediately forces the serial
processing to happen as soon as the interrupt returns (as a bottom half
routine). It's been a layering violation, though, so I wouldn't really
want to do this unless someone can show that it would really make a big

- Ted