On Tue, Jul 17, 2012 at 08:57:19PM +0200, Linus Walleij wrote: > So the IRQ will be auto-sampled now or something? > > Sorry for not quite following, which commit do I look at to > understand this now... Yes, there was a huge discussion on LKML about two weeks ago. The key commit that will be going in during the next merge window is: http://git.kernel.org/?p=linux/kernel/git/tytso/random.git;a=commitdiff;h=775f4b297b780601e61787b766f306ed3e1d23eb There are a whole lot of other changes, of course, but that's the key change which IRQF_SAMPLE_RANDOM a no-op. People have tested this under extreme conditions (high speed networking tests with no interrupt mitigations, etc.) and the patch as tweaked had no measurable overhead, so we can simply sample every single commit with a low-overhead fast path which uses per-cpu buffers, and then mix into the /dev/random entropy pool less frequently (which is still fast, but requires a few more memory accesses to shared memory that may incur delays due to cache line bounces). - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-next" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
