Date: Mon, 27 Aug 2018 19:36:25 +0200 From: magnum <john.magnum@...hmail.com> To: john-users@...ts.openwall.com Subject: Re: Beignet: unable to find good values for local_work_size On 2018-08-27 11:54, Matus UHLAR - fantomas wrote: > for a few weeks, the beignet OpenCL driver reports this message: > > Loaded 1 password hash (mysql-sha1-opencl, MySQL 4.1+ [SHA1 OpenCL]) > Beignet: "unable to find good values for local_work_size[i], please > provide\n" " local_work_size explicitly, you can find good values with\n" > " trial-and-error method." > > I understand it as the driver does not provide any useful value and the > john > is just guesssing. > > How can I test for the proper value? can I do it at runtime? That message comes from Beignet, not john. What is triggering it is likely that we deliberately use a local work size of NULL for incomplete batches (eg. the very last batch in a session). There's not really any way you can provide it... short of reverting to some commit before https://github.com/magnumripper/JohnTheRipper/issues/3223 where we had another scheme (which had other problems). I would report it to them as a bug, because according to the OpenCL spec. it should handle it. I believe what most drivers/runtimes do is find greatest divisor of GWS that is less than or equal to highest possible LWS, and use that. Does it crash/abort or is this just a warning message? It could be that it simply warns and then use an LWS of 1 which is suboptimal but works fine in this case. magnum
Powered by blists - more mailing lists
Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.