Date: Thu, 3 Mar 2005 00:24:58 -0600 From: Alan Cox <alc@cs.rice.edu> To: Doug White <dwhite@FreeBSD.org> Cc: cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/kern uipc_mbuf.c Message-ID: <20050303062458.GA15192@cs.rice.edu> In-Reply-To: <200503030241.j232fbCn032297@repoman.freebsd.org> References: <200503030241.j232fbCn032297@repoman.freebsd.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Thu, Mar 03, 2005 at 02:41:37AM +0000, Doug White wrote: > dwhite 2005-03-03 02:41:37 UTC > > FreeBSD src repository > > Modified files: > sys/kern uipc_mbuf.c > Log: > Insert volatile cast to discourage gcc from optimizing the read outside > of the while loop. > > Suggested by: alc > MFC after: 1 day > > Revision Changes Path > 1.144 +4 -1 src/sys/kern/uipc_mbuf.c I tend to believe that the sparc64's casa() implementation is the real culprit here. Specifically, I don't believe the right asm operand constraints are being used. If I'm correct, the addition of volatile here is unnecessary. Can we hold the MFC until this hypothesis is proven or disproven? Alan
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20050303062458.GA15192>