Follow @Openwall on Twitter for new release announcements and other news
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Date: Mon, 27 May 2013 21:39:10 +0200
From: magnum <john.magnum@...hmail.com>
To: "john-dev@...ts.openwall.com" <john-dev@...ts.openwall.com>
Subject: OMP for raw formats

Jim recently enabled OMP for the fast raw formats and that ymade me enable it for nt2 as well (it was there but disabled). They all work fine on Intel i7 but I see massive performance regressions on AMD hardware, not only XOP/Bull but also older AMD. Even using OMP_NUM_THREADS=1 the speed is terrible. I think we need to revert this or figure out some way to handle it.

One way to handle it is to add some macro like USE_RAW_OMP to Makefile (perhaps default commented out, perhaps not?) and only enable OMP for these formats if it's defined.

Or maybe it can be tweaked. I have tried bumping OMP_SCALE to astronomous figures to no avail.

This problem likely applies to dynamic too, but I never noticed (and did not check now).

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.