On Fri, Apr 20, 2018 at 04:30:02PM -0700, Eric Biggers wrote: > Improve fscrypt read performance by switching the decryption workqueue > from bound to unbound. With the bound workqueue, when multiple bios > completed on the same CPU, they were decrypted on that same CPU. But > with the unbound queue, they are now decrypted in parallel on any CPU. > > Although fscrypt read performance can be tough to measure due to the > many sources of variation, this change is most beneficial when > decryption is slow, e.g. on CPUs without AES instructions. For example, > I timed tarring up encrypted directories on f2fs. On x86 with AES-NI > instructions disabled, the unbound workqueue improved performance by > about 25-35%, using 1 to NUM_CPUs jobs with 4 or 8 CPUs available. But > with AES-NI enabled, performance was unchanged to within ~2%. > > I also did the same test on a quad-core ARM CPU using xts-speck128-neon > encryption. There performance was usually about 10% better with the > unbound workqueue, bringing it closer to the unencrypted speed. > > The unbound workqueue may be worse in some cases due to worse locality, > but I think it's still the better default. dm-crypt uses an unbound > workqueue by default too, so this change makes fscrypt match. > > Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx> Applied, thanks. - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-fscrypt" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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