From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.5 required=3.0 tests=DKIM_ADSP_CUSTOM_MED, DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 79E4EC43331 for ; Thu, 26 Mar 2020 17:05:14 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 4B2AE20714 for ; Thu, 26 Mar 2020 17:05:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="syEGKcVb" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4B2AE20714 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=intel-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 9FCF96E348; Thu, 26 Mar 2020 17:05:13 +0000 (UTC) Received: from mail-vk1-xa42.google.com (mail-vk1-xa42.google.com [IPv6:2607:f8b0:4864:20::a42]) by gabe.freedesktop.org (Postfix) with ESMTPS id E8AFD6E348 for ; Thu, 26 Mar 2020 17:05:11 +0000 (UTC) Received: by mail-vk1-xa42.google.com with SMTP id e20so1885523vke.9 for ; Thu, 26 Mar 2020 10:05:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=WmuSk4AyJHRN2j9GxvG8usTX/OHvru+qJwz1z4lwtsk=; b=syEGKcVbI2Ke8uhP3lOKMLpBA6CNg3rBVPRjcyaH7nTBY/FSnN9+h3VpaT8gw5u/XF fP4FWbb58x/3piXQ6eMceXlzMoZyuwD1b1IrmFlKkeTx9tE9iyI4oaEcFPsKYcVN+sT+ j+V5XzbGVQjhxxqvIs12ESVb+52CgMQAm3+IQvXZgsiCfIeluih014DbDkbh3Wk2rS4D jx5WeKG2lOe3S+z1gc/6cTau3IpleVQvzath9hVEp4lnvKvdnTVyHdRw6r9QJlwIVv05 6MduP3zJAyXewVnpXTtruP95S3DzrxskliDslRVniTKxobooxRSPt4R/WeLUV2idt55Y pY/w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=WmuSk4AyJHRN2j9GxvG8usTX/OHvru+qJwz1z4lwtsk=; b=uLJzHU708s+PF2hQLZD0KbIJbGSfNeZunxUb7rzj7IED4/oyzjtoqXloQLuIL5y98n /rgTVp/SEtKb/LXY9cbdaEqLHsca7wAi7razSZUV1+B8L/fX3ZkIaw4tdlr9U2kXHZ4E 7Ze2NhehlTciQ+Fw1qRGpj0DGChkdV82XVPz/mZHjsCG9KWyusgyrh8IXkEHHai66RUC wnYuY5wsyyfX4lo4VXL31fHBax/y/Yi59dfaKSZzRZ5QyltcHubF2FIbTi3DdejBCXgm HUXHiWC4/dTfrLdtMUQNquN3gdQ2aegbuqxIr1qfTjxdbopILQrZrwwGp9lBm+54gpC2 jI1Q== X-Gm-Message-State: ANhLgQ0aVwEl237xj+o6cwmvVYPykrPpfZmYo5san0GAF0HIVdaKjhLc 5AF23MtTi4HWcW5vhbxrnGsd4Pji4AOivEmEDSIrlGla X-Google-Smtp-Source: ADFU+vsWgNqJupc9GzkE+sKG2Gs1FwDINk93ZG1vs+CgWm5jGMqCmzbv+DCfCFmPrnvOv5dTKv0m1N6XyEzaWYJCN/k= X-Received: by 2002:a1f:93d4:: with SMTP id v203mr7171613vkd.78.1585242309834; Thu, 26 Mar 2020 10:05:09 -0700 (PDT) MIME-Version: 1.0 References: <20200325192429.GA8865@SDF.ORG> In-Reply-To: <20200325192429.GA8865@SDF.ORG> From: Matthew Auld Date: Thu, 26 Mar 2020 17:04:43 +0000 Message-ID: To: George Spelvin Subject: Re: [Intel-gfx] [PATCH] drivers/gpu/drm/i915/selftests/i915_buddy.c: Fix bug X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Intel Graphics Development , Matthew Auld Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On Wed, 25 Mar 2020 at 21:23, George Spelvin wrote: > > igt_mm_config() calls ilog2() on the (pseudo)random 21-bit number > s>>12. Once in 2 million seeds, this is zero and ilog2 summons > the nasal demons. > > There was an attempt to handle this case with a max(), but that's > too late; ms could already be something bizarre. > > Given that the low 12 bits of s and ms are always zero, it's a lot > simpler just to divide them by 4096, then everything fits into 32 > bits, and we can easily generate a random number 1 <= s <= 0x1fffff. > > Signed-off-by: George Spelvin > Fixes: 14d1b9a6247c > Cc: Matthew Auld > Cc: Jani Nikula > Cc: Joonas Lahtinen > Cc: Rodrigo Vivi > Cc: intel-gfx@lists.freedesktop.org Reviewed-by: Matthew Auld _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx