On Tue, Apr 14, 2009 at 12:45:41PM -0400, Jeff Moyer wrote: > So, if you're continuously submitting async read I/O, you will starve > out the fork() call indefinitely. I agree that you want to allow IIRC rwsem good enough to stop the down_read when a down_write is blocked. Otherwise page fault flood in threads would also starve any mmap or similar call. Still with this approach fork will start to hang indefinitely waiting for I/O, making it an I/O bound call, and not a CPU call anymore, which may severely impact interactive-ness of applications. As long as fork is useful in the first place to provide memory protection of different code with different memory-corruption-trust-levels (otherwise nobody should use fork at all, and vfork [or better spawn] should become the only option), then fork from a thread pool is also reasonable. Either fork is totally useless as a whole (which I wouldn't argue too much about), or if you agree fork makes any sense, it can also make sense if intermixed with clone(CLONE_VM) and hopefully it should behave CPU bound like CLONE_VM. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
