From mjacob@feral.com Tue Jul 18 00:08:29 2000
Date: Mon, 17 Jul 2000 20:21:07 -0700 (PDT)
From: Matthew Jacob <mjacob@feral.com>
To: Andrew Gallatin <gallatin@cs.duke.edu>, Doug Rabson <dfr@nlsystems.com>
Subject: Re: fxp0 hangs on a PC164 using STABLE


I'm a little uneasy about this. It's likely to make the FXP unhappy, to say
the least. If you *do* use this, put memory barriers in before and after
the the flag update.

Doug, Drew- I'm not sure whether LDL_L/STL_C and LDQ_L/STQ_C are cognizant of
I/O device accesses to memory or not- my green book sayeth not. It's possible
not. It'd be preferrable, IMO, to write 5 lines of inline assembly code that
use the load_locked && store_locked_conditional rather than hit the FXP over
the head. Anybody else know? Or should we go ask Chris/Jason/Ross (I'm sure
Ross'd know)?

-matt









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