On Sun, 19 Apr 2009, Robert Watson wrote:
Log:
For each architecture, define CACHE_LINE_SHIFT and a derived
CACHE_LINE_SIZE constant. These constants are intended to
over-estimate the cache line size, and be used at compile-time
when a run-time tuning alternative isn't appropriate or
available.
Defaults for all architectures are 64 bytes, except powerpc
where it is 128 bytes (used on G5 systems).
...
Modified: head/sys/amd64/include/param.h
==============================================================================
--- head/sys/amd64/include/param.h Sun Apr 19 18:23:23 2009
(r191275)
+++ head/sys/amd64/include/param.h Sun Apr 19 20:19:13 2009
(r191276)
@@ -89,6 +89,10 @@
#define ALIGN(p) _ALIGN(p)
#define ALIGNED_POINTER(p,t) _ALIGNED_POINTER(p,t)
+#ifndef CACHE_LINE_SHIFT
+#define CACHE_LINE_SHIFT 6
+#endif
+#define CACHE_LINE_SIZE (1 << CACHE_LINE_SHIFT)
This still has the bogus ifdef. Overriding the definition is difficult
to do consistently even in a kernel with no modules, since CACHE_LINE_SIZE
is not a kernel option. Overriding the definition makes negative sense
since the value is a maximum-maximum (possibly larger than strictly needed)
so that it can be constant.
Bruce
_______________________________________________
svn-src-all@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/svn-src-all
To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
