On 12.11.2010, 08:34 Huang Ying wrote: On Fri, 2010-11-12 at 15:30 +0800, Mathias Krause wrote: >> On 12.11.2010, 01:33 Huang Ying wrote: >>> Why the improvement of ECB is so small? I can not understand it. It >>> should be as big as CBC. >> >> I don't know why the ECB variant is so slow compared to the other variants. >> But it is so even for the current x86-64 version. See the above values for >> "x86-64 (old)". I setup dm-crypt for this test like this: >> # cryptsetup -c aes-ecb-plain -d /dev/urandom create cfs /dev/loop0 >> >> What where the numbers you measured in your tests while developing the >> x86-64 version? > > Can't remember the number. Do you have interest to dig into the issue? I looked at /proc/crypto while doing the tests again and noticed that ECB isn't handled using cryptd, while all other modes, e.g. CBC and CTR, are. The reason for that seems to be that for ECB, and only for ECB, the kernel is using the synchronous block algorithm instead of the asynchronous one. So the question is: Why is the ECB variant handled using the synchronous cipher -- because of the missing iv handling in this mode? Best regards, Mathias -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
