On Sun, Nov 22, 2009 at 4:01 AM, Segher Boessenkool <seg...@kernel.crashing.org> wrote: >>> You need to be a bit more careful tho. You must not allow RAM managed by >>> the kernel to be mapped non-cachable. >> >> Even if the user explicitly sets the O_SYNC flag? IMHO, it's a bug of >> the application if it uses O_SYNC on main memory to be mmap'ed later. >> And we don't need to cover up the bug. > > Is that "embedded thinking"? Conflicts like this cause machine checks or > checkstops on many PowerPC implementations, we do not normally allow such > to be caused by userland.
So what you are saying is that if the kernel has mapped a physical page as cacheable while user application is trying to map it as non-cacheable, there will be machine checks and checkstops rather than just performance drop? This is new to me. Could you elaborate a bit? Thanks. - Leo _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
