Date: Wed, 10 Feb 2016 21:57:56 +0000 From: bugzilla-noreply@freebsd.org To: freebsd-bugs@FreeBSD.org Subject: [Bug 207068] hwpmc wrap around/sign extension Message-ID: <bug-207068-8-GKW4PEBpmf@https.bugs.freebsd.org/bugzilla/> In-Reply-To: <bug-207068-8@https.bugs.freebsd.org/bugzilla/> References: <bug-207068-8@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D207068 --- Comment #6 from joss.upton@yahoo.com --- (In reply to joss.upton from comment #5) Actually, the best test might be to do this: uint64_t num; num =3D rdmsr(0xc1); printf("init: %lx\n", num); wrmsr(0xc1, 0x80000000); num =3D rdmsr(0xc1); printf("after e31: %lx\n", num); When I do this: init: 0 after e31: ffff80000000 This behavior is correct according to the Intel manual, but causes issues w= ith negative increments if you race it long enough. --=20 You are receiving this mail because: You are the assignee for the bug.=
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