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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9D537C74A5B for ; Wed, 29 Mar 2023 06:56:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229711AbjC2G4N (ORCPT ); Wed, 29 Mar 2023 02:56:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57410 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229484AbjC2G4L (ORCPT ); Wed, 29 Mar 2023 02:56:11 -0400 Received: from mail-yw1-x114a.google.com (mail-yw1-x114a.google.com [IPv6:2607:f8b0:4864:20::114a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4D54E2D5E for ; Tue, 28 Mar 2023 23:56:09 -0700 (PDT) Received: by mail-yw1-x114a.google.com with SMTP id 00721157ae682-5458dde029bso147104777b3.13 for ; Tue, 28 Mar 2023 23:56:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; t=1680072968; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=+6FGLc7DezyggwEDA6SlL49TwBy1ESwTS9CYC+SnZVM=; b=ip2ObvbwjKAThNEYJ+mAP6NxZUtLziQmG7qqimp6FSTliXsWvpp5OlH/S6qdrm6D4K IZicU6MzuIcQCE61oioHol6VvVAaXHIE2dhWe8vuYyDhNoqEF4mloHHEnoPtfVHcGjfO wyOpfLQ6H4o5KUW557F4zn4wpZzfuWs34QzeytMTnFRjkNgloAfzhWoWJ4+dReISEOZP 1rYuW6kB2TWKMSZvrnsbDg6JDBJqvZGSBzqMLAdDCWB8oHH9sNVSUcHox19tuqORYQv+ VXEem2/SMiKw6ug/GxM5zdBr9xY2Tv/ZorcJKFJg0KtMQRKjxshwFRGO2BOugKdYpD2h yDJw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1680072968; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=+6FGLc7DezyggwEDA6SlL49TwBy1ESwTS9CYC+SnZVM=; b=tNKPU5GYEWqbrh4r4rZKAMSbUQlsFXfoOvghRLhqApwc4xKPO1rrvmC0Bi+QRbOxll qeHu8RCK9AFItwbUZP4O4DSLzUDbZehEPD+HRdhGCrnCjJiopnwE1K8jHlal4FPv2xUc h51R1VMmRDMxsIrnxqc39ZLpgX6DTeHT+RC/k9SxktVgYonOadZ7U143U6blcw/4bPHD HqVTRFwGjO7VE2drtrmFPplddeINQz4EqIlHK2YTFAVKQTrJKsT8cQkeazXQU2SOvlzm 2K5OF+RWUHSJI8CX6mTQ1AwUwxjyWjOA7XG832cBysgxr9FeaXZWh2SmqOkEx+qVcfKf cysQ== X-Gm-Message-State: AAQBX9cneSe3rPOnKP79JujWNpzwpax4hYGzIRBPqnSZbVatEHuq7Nq6 rRGgl6oXlYFl6BD/T9u9kDbx4Hvc11v6Sw== X-Google-Smtp-Source: AKy350aW0oXIdid/PamI5UXVN98qdXztLtQJ5ZEohZbEr95Se93u+cliygWLulbEfIGKqnK6l7npl+MIXUEaIA== X-Received: from slicestar.c.googlers.com ([fda3:e722:ac3:cc00:4f:4b78:c0a8:20a1]) (user=davidgow job=sendgmr) by 2002:a05:6902:1547:b0:b46:4a5e:365f with SMTP id r7-20020a056902154700b00b464a5e365fmr12420681ybu.8.1680072968620; Tue, 28 Mar 2023 23:56:08 -0700 (PDT) Date: Wed, 29 Mar 2023 14:55:34 +0800 In-Reply-To: <20230329065532.2122295-1-davidgow@google.com> Mime-Version: 1.0 References: <20230329065532.2122295-1-davidgow@google.com> X-Mailer: git-send-email 2.40.0.348.gf938b09366-goog Message-ID: <20230329065532.2122295-2-davidgow@google.com> Subject: [PATCH 2/2] drm: test: Fix 32-bit issue in drm_buddy_test From: David Gow To: "=?UTF-8?q?Lu=C3=ADs=20Mendes?=" , "=?UTF-8?q?Christian=20K=C3=B6nig?=" , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Daniel Vetter , "=?UTF-8?q?Ma=C3=ADra=20Canal?=" , Arthur Grillo Cc: David Gow , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The drm_buddy_test KUnit tests verify that returned blocks have sizes which are powers of two using is_power_of_2(). However, is_power_of_2() operations on a 'long', but the block size is a u64. So on systems where long is 32-bit, this can sometimes fail even on correctly sized blocks. This only reproduces randomly, as the parameters passed to the buddy allocator in this test are random. The seed 0xb2e06022 reproduced it fine here. For now, just hardcode an is_power_of_2() implementation using x & (x - 1). Signed-off-by: David Gow --- There are actually a couple of is_power_of_2_u64() implementations already around in: - drivers/gpu/drm/i915/i915_utils.h - fs/btrfs/misc.h (called is_power_of_two_u64) So the ideal thing would be to consolidate these in one place. --- drivers/gpu/drm/tests/drm_buddy_test.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/tests/drm_buddy_test.c b/drivers/gpu/drm/tests/drm_buddy_test.c index f8ee714df396..09ee6f6af896 100644 --- a/drivers/gpu/drm/tests/drm_buddy_test.c +++ b/drivers/gpu/drm/tests/drm_buddy_test.c @@ -89,7 +89,8 @@ static int check_block(struct kunit *test, struct drm_buddy *mm, err = -EINVAL; } - if (!is_power_of_2(block_size)) { + /* We can't use is_power_of_2() for a u64 on 32-bit systems. */ + if (block_size & (block_size - 1)) { kunit_err(test, "block size not power of two\n"); err = -EINVAL; } -- 2.40.0.348.gf938b09366-goog