Date: Thu, 20 Jul 2000 13:03:48 -0700 (PDT) From: Matthew Jacob <mjacob@feral.com> To: =?ISO-8859-1?Q?G=E9rard_Roudier?= <groudier@club-internet.fr> Cc: freebsd-alpha@FreeBSD.ORG Subject: Re: more on- Re: fxp0 hangs on a PC164 using STABLE Message-ID: <Pine.BSF.4.10.10007201302570.45768-100000@beppo.feral.com> In-Reply-To: <Pine.LNX.4.10.10007202121140.1919-100000@linux.local>
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> Hmmm... I meant, first revert the patch, then add the barriers. > Damn... I know I am idiot but I thought nobody else discovered it. ;) :-) > > There's every reason to assume that they would be useful in i386 too, no? > > They may well be so, for example, in the situation of the PCI device and > its software driver sharing a completion queue in memory. Then a > serialization instruction may be needed after having picked the completion > thing from the completion queue and before checking the associated status > data. This is due to the PII/PIII also reodering LOADs/STOREs in some way. > > > It sounds to me that this would be a good argument for a simple inline or asm > > for both i386 && alpha ports. > > Agreed. > > > Now, the sparc port will be more interesting because a plain 'memory barrier' > > is not what's there - instead you have to do explicit address based flushing > > and/or invalidation (depending on the platform). > > Seems Linux does cope of that without too much complexity. Ooh, I those kind of arguments are tough to answer....:-) To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-alpha" in the body of the message
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