Date: Thu, 8 Jul 2010 03:41:57 +0000 (UTC) From: Lawrence Stewart <lstewart@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-8@freebsd.org Subject: svn commit: r209790 - stable/8/sys/sys Message-ID: <201007080341.o683fvAH092590@svn.freebsd.org>
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Author: lstewart Date: Thu Jul 8 03:41:57 2010 New Revision: 209790 URL: http://svn.freebsd.org/changeset/base/209790 Log: MFC r209119,209325: - Add a utility macro to simplify calculating an aggregate sum from a DPCPU counter variable. - Rename the internal for loop iterator to "_i" to avoid potential shadowing of external variables named "i". The "_" prefix is reserved for infrastructure type code and is therefore not expected to be used by normal code likely to call DPCPU_SUM(). [1] - Change DPCPU_SUM to return the sum rather than calculate and assign it internally. Usage is now: "sum = DPCPU_SUM(dpcpu_var, member_to_sum);" [2] - Fix some style nits. [3] Sponsored by: FreeBSD Foundation Suggested by: bde [3], mdf [1], kib [1,2], pjd [1,3] Reviewed by: jhb, rpaulo, rwatson (old version of r209119), kib (r209325) Modified: stable/8/sys/sys/pcpu.h Directory Properties: stable/8/sys/ (props changed) stable/8/sys/amd64/include/xen/ (props changed) stable/8/sys/cddl/contrib/opensolaris/ (props changed) stable/8/sys/contrib/dev/acpica/ (props changed) stable/8/sys/contrib/pf/ (props changed) stable/8/sys/dev/xen/xenpci/ (props changed) Modified: stable/8/sys/sys/pcpu.h ============================================================================== --- stable/8/sys/sys/pcpu.h Thu Jul 8 03:35:00 2010 (r209789) +++ stable/8/sys/sys/pcpu.h Thu Jul 8 03:41:57 2010 (r209790) @@ -109,6 +109,21 @@ extern uintptr_t dpcpu_off[]; #define DPCPU_ID_GET(i, n) (*DPCPU_ID_PTR(i, n)) #define DPCPU_ID_SET(i, n, v) (*DPCPU_ID_PTR(i, n) = v) +/* + * Utility macros. + */ +#define DPCPU_SUM(n, var) __extension__ \ +({ \ + u_int _i; \ + __typeof((DPCPU_PTR(n))->var) sum; \ + \ + sum = 0; \ + CPU_FOREACH(_i) { \ + sum += (DPCPU_ID_PTR(_i, n))->var; \ + } \ + sum; \ +}) + /* * XXXUPS remove as soon as we have per cpu variable * linker sets and can define rm_queue in _rm_lock.h
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