On Mon, Aug 01, 2005 at 05:54:33PM +0100, Catalin Marinas wrote: > Russell King <[EMAIL PROTECTED]> wrote: > > On Mon, Aug 01, 2005 at 01:24:04PM +0100, Catalin Marinas wrote: > >> "David S. Miller" <[EMAIL PROTECTED]> wrote: > >> > If one cpu stores, does it get picked up in the other cpu's I-cache? > >> > >> It only gets picked up by the other CPU's D-cache (which is fully > >> coherent between cores). The I-cache needs to be invalidated on each > >> CPU. > > > > Are you sure about this requirement? I see no evidence of it in Harry's > > patch set. > > I asked the people that know more about this architecture than me and > they confirmed that this is a requirement. I will double check > tomorrow with the people that did the initial Linux support. > > I haven't checked the original patch but it might work (by luck) > without the I-cache invalidation (and without stressing it too > much). This is because you might do a full mm flush when a process > exits and the I-cache would be clean for newly allocated pages (only > the D-cache needs flushing). If you don't overload memory, you don't > get pages swapped-out/removed and the code in a page for a given > process might remain unchanged until the process exits.
Given that it's sometimes going wrong as early as the first process, I doubt this is what's happening. The i-cache will be clean at this point for the userspace programs. -- Russell King Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/ maintainer of: 2.6 Serial core - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
