Date: Tue, 18 Mar 2008 08:39:12 +0000 (UTC) From: Adrian Chadd <adrian@FreeBSD.org> To: src-committers@FreeBSD.org, cvs-src@FreeBSD.org, cvs-all@FreeBSD.org Subject: cvs commit: src/sys/dev/hwpmc hwpmc_amd.c Message-ID: <200803180839.m2I8dCgH073280@repoman.freebsd.org>
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adrian 2008-03-18 08:39:12 UTC
FreeBSD src repository
Modified files:
sys/dev/hwpmc hwpmc_amd.c
Log:
Sign-extend the 48-bit AMD PMC counter before treating it to a 64-bit
2's compliment.
The 2's compliment transform is done so a "count down" sampling interval
can be converted into a "count up" PMC value. a 2's complimented 'count down'
value is written to the PMC counter; then the read-back counter is reverted
via another 2's compliment.
PR: kern/121660
Reviewed by: jkoshy
Approved by: jkoshy
MFC after: 1 week
Revision Changes Path
1.16 +8 -5 src/sys/dev/hwpmc/hwpmc_amd.c
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