On Sun, Jun 13, 2010 at 01:59:11PM +0000, m...@freebsd.org wrote: > On Sun, Jun 13, 2010 at 10:10 AM, Pawel Jakub Dawidek <p...@freebsd.org> > wrote: > > On Sun, Jun 13, 2010 at 02:39:55AM +0000, Lawrence Stewart wrote: > >> Author: lstewart > >> Date: Sun Jun 13 02:39:55 2010 > >> New Revision: 209119 > >> URL: http://svn.freebsd.org/changeset/base/209119 > >> > >> Log: > >> ? Add a utility macro to simplify calculating an aggregate sum from a DPCPU > >> ? counter variable. > >> > >> ? Sponsored by: ? ? ? FreeBSD Foundation > >> ? Reviewed by: ? ? ? ?jhb, rpaulo, rwatson (previous version of patch) > >> ? MFC after: ?1 week > >> > >> Modified: > >> ? head/sys/sys/pcpu.h > >> > >> Modified: head/sys/sys/pcpu.h > >> ============================================================================== > >> --- head/sys/sys/pcpu.h ? ? ? Sun Jun 13 01:27:29 2010 ? ? ? ?(r209118) > >> +++ head/sys/sys/pcpu.h ? ? ? Sun Jun 13 02:39:55 2010 ? ? ? ?(r209119) > >> @@ -106,6 +106,17 @@ 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, sum) ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? > >> ? ? \ > >> +do { ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? \ > >> + ? ? (sum) = 0; ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?\ > >> + ? ? u_int i; ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?\ > >> + ? ? CPU_FOREACH(i) ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?\ > >> + ? ? ? ? ? ? (sum) += (DPCPU_ID_PTR(i, n))->var; ? ? ? ? ? ? ? ? ? ? \ > >> +} while (0) > > > > I'd suggest first swapping variable declaration and '(sum) = 0;'. > > Also using 'i' as a counter in macro can easly lead to name collision. > > If you need to do it, I'd suggest '_i' or something. > > Maybe it would be better to make it an inline function rather than macro? > > (Relevant but almost a thread hijack): > > At Isilon we've run into a lot of problems with variable declarations > in macros, especially with -Wshadow turned on. We ended up > backporting __COUNTER__ from later versions of gcc and then using it > to make unique variable names. > > - is the backport (or a fresh implementation) something that could be > done within the scope of the GPL license? > - is it something FreeBSD would be interested in? > - is __COUNTER__ supported by clang?
__COUNTER__ is supported by clang _______________________________________________ svn-src-head@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
