>I want all my file system's operations to be complete uncached and >synchronous, but I also want to support mmap. >... >What am I doing wrong? Is what I'm trying to do impossible, and if >so, how can I get as close as possible?
It looks to me like you're running into the fundamental limitation that the CPU doesn't notify Linux every time you store into a memory location. It does, though, set the dirty flag in the page table, and Linux eventually inspects that flag and finds out that you have stored in the past. At that time, it can call set_page_dirty. Without knowing what properties of not having a cache you were hoping for, I couldn't say what alternative would be closest to this. Hypothetically, if you had a backing storage device that could do memory mapped I/O, you could have mmapped direct I/O. -- Bryan Henderson IBM Almaden Research Center San Jose CA Filesystems - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
