Hi Trond, We had an application writer report a performance regression between 2.6.23 and later kernels that we ultimately tracked down to your patch 94387fb1aa, "NFS: Add the helper nfs_vm_page_mkwrite". It turns out the application was accidentally using a writable shared mmap between two processes on an NFS mount instead of tmpfs. The setup is fixed now, but I'm still surprised by the 7x slowdown caused by this patch for application runtime when the mmap is shared between two processes writing to it. If there is only one process that maps the file, there is no measureable slowdown. Is that an expected side-effect of your patch, or something that should not have happened? Arnd <>< -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
