On Oct 25, 2009, at 1:25 PM, Marius Strobl wrote:
Do you have a simple test case demonstrating the need for I-cache synchronisation?
I typically use GDB. If breakpoints aren't being hit or next isn't behaving correctly, you typically have an I-cache problem. If you get to run GDB, you probably already know whether it's needed, because processes tend to die with random signals at startup when the architecture needs explicit I-cache coherency logic and the kernel doesn't have it. A special case I would say is executing from a memory disk. The I/O path contains bcopy() operations, which dirty the D-cache and trigger I-cache coherency bugs pretty well. I didn't have issues with that on my Netra, so I didn't implement pmap_sync_icache for sparc64. This is not to say that it's absolutely not needed, just that GDB didn't expose problems. If sparc64 has some of the same kluges powerpc had, then I-cache coherency is handled in some other (most likely a sub-optimal) way. FYI, -- Marcel Moolenaar xcl...@mac.com _______________________________________________ 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"
