On Mon, Jun 24, 2013 at 10:07:51AM +0200, Ingo Molnar wrote: > I'm wondering, how will this scheme work if the IO completion latency is a > lot more than the 5 usecs in the testcase? What if it takes 20 usecs or > 100 usecs or more?
There's clearly a threshold at which it stops making sense, and our current NAND-based SSDs are almost certainly on the wrong side of that threshold! I can't wait for one of the "post-NAND" technologies to make it to market in some form that makes it economical to use in an SSD. The problem is that some of the people who are looking at those technologies are crazy. They want to "bypass the kernel" and "do user space I/O" because "the kernel is too slow". This patch is part of an effort to show them how crazy they are. And even if it doesn't convince them, at least users who refuse to rewrite their applications to take advantage of magical userspace I/O libraries will see real performance benefits. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
