Skip site navigation (1)Skip section navigation (2)
Date:      Wed, 27 Aug 1997 14:39:03 -0600
From:      Steve Passe <smp@csn.net>
To:        Terry Lambert <terry@lambert.org>
Cc:        petrilli@amber.org, mestery@winternet.com, peters@gil.com.au, smp@FreeBSD.ORG
Subject:   Re: A how does it work question. 
Message-ID:  <199708272039.OAA29795@Ilsa.StevesCafe.com>
In-Reply-To: Your message of "Wed, 27 Aug 1997 13:28:07 PDT." <199708272028.NAA06259@phaeton.artisoft.com> 

next in thread | previous in thread | raw e-mail | index | archive | help
Hi,

> >  - fast intrrrupts no longer use the giant lock.  There is a simple lock that
> >    prevents more than 1 fast interrupt from being in the kernel at once,
> >  ...
> >    the kernel proper MP-safe, but each and EVERY driver needs work.
> 
> Actually, you need a driver flag, and if it is not set, invoke the
> simple lock.  This would let you set the flag (MPSAFE?) on drivers
> which didn't have the problem, and allow for a staged migration.
> At least one driver needs to be safed before the resto of them can
> be, using it as an example.

thats already planned.  sio.c and cy.c are already MP-safe from the kernel's
point of view.  The problem is that they are not 'concurrancy-safe', ie
they never expected to be run concurrently by more than 1 CPU.  This
sort of problem is not so well demonstrated with an example driver, as the
specific issues will vary from driver to driver.
--
Steve Passe	| powered by
smp@csn.net	|            Symmetric MultiProcessor FreeBSD





Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199708272039.OAA29795>