From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id E6961480952 for ; Thu, 3 Sep 2026 11:41:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788435670; cv=none; b=XmpsJi8fuMxg3Q2Z/xNyioAQtCxvu8uoZtIbJ3x7n3PVD2lN0KzPLXf7baueSt9YabLRYB2jcgwAr8RKGLbpwSAC9FlSd8l0CzZf8G8/Dsw63iPkNfQ33rjalvKhCLt+/DgmSKKBCT/qtj5flxx6ue7hKnIEmz0BL6cuCagQSPs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788435670; c=relaxed/simple; bh=EMBeTImvJnNZfdUizGQ85PK2JMB9YX9D70xQZ2VPWYc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=D7sMOXK+LIKDtRE15F9F7MsiLT/lCq7FTuuh9/m7aWqa6zGljP0t8IT1En+kYmO1QJepHeHwn8z9jceF3zOU8fBPi9a6MYX4HBqd+18SmxPcT96Fhrlncdf7LCBGLzxsAf0So7+g7pdRdotNCp0xXBNaNSsz9LEu4WS3Hv5ykzg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=DWz7o0TY; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="DWz7o0TY" Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 36EB91596; Thu, 3 Sep 2026 04:40:54 -0700 (PDT) Received: from e129823.arm.com (e129823.arm.com [10.2.213.3]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id AA8B03F7D8; Thu, 3 Sep 2026 04:40:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1788435658; bh=EMBeTImvJnNZfdUizGQ85PK2JMB9YX9D70xQZ2VPWYc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=DWz7o0TYxCiqmCVFI4i95OMzzFJELJIhGrqsXSzffTdbn99riEXH11OBH5bM5dXGY /4QhFYo8PQSuCjouR+QtfCj5xKO+UmHxc0Y0wXH3xI/3jSVTtJLb8Nbsfl3yYRR9HQ cESHc3Cx+1uXiHcsWRLhZ+AncOaZma93SrnFR9G4= Date: Thu, 3 Sep 2026 12:40:52 +0100 From: Yeoreum Yun To: Sarthak Sharma Cc: Yeoreum Yun , linux-mm@kvack.org, linux-kselftest@vger.kernel.org, akpm@linux-foundation.org, david@kernel.org, ljs@kernel.org, liam@infradead.org, vbabka@kernel.org, rppt@kernel.org, surenb@google.com, mhocko@suse.com, shuah@kernel.org, ziy@nvidia.com, baolin.wang@linux.alibaba.com, nico.pache@linux.dev, ryan.roberts@arm.com, dev.jain@arm.com, baohua@kernel.org, lance.yang@linux.dev, usama.arif@linux.dev, kas@kernel.org Subject: Re: [PATCH] kselftest: mm: remove HPAGE_SIZE and HPAGE_SHIFT macro Message-ID: References: <20260902175611.1241118-1-yeoreum.yun@arm.com> <7108538a-5581-4586-bc12-224683d0c25e@arm.com> Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <7108538a-5581-4586-bc12-224683d0c25e@arm.com> Hi Sarthak, > Hi Yeoreum! > > On 9/2/26 11:26 PM, Yeoreum Yun wrote: > > HPAGE_SIZE and HPAGE_SHIFT macro is written based on the 4KB PAGE_SIZE. > > When this macro is used in some test, test result would be strange in > > the system where PAGE_SIZE is more than 4KB. > > > > Here is example with transhuge-stress test with 16KB PAGE_SIZE: > > > > transhuge-stress: allocate 61073 transhuge pages, using 122146 MiB virtual memory and 1908 MiB of ram > > 3.292 s/loop, 0.054 ms/page, 37106.002 MiB/s 2566 succeed, 58507 failed, 2566 different pages > > 0.591 s/loop, 0.010 ms/page, 206850.792 MiB/s 0 succeed, 61073 failed, 0 different pages > > 0.527 s/loop, 0.009 ms/page, 231895.107 MiB/s 0 succeed, 61073 failed, 0 different pages > > 0.527 s/loop, 0.009 ms/page, 231839.704 MiB/s 0 succeed, 61073 failed, 0 different pages > > 0.528 s/loop, 0.009 ms/page, 231544.782 MiB/s 0 succeed, 61073 failed, 0 different pages > > 0.528 s/loop, 0.009 ms/page, 231462.074 MiB/s 0 succeed, 61073 failed, 0 different pages > > 0.527 s/loop, 0.009 ms/page, 231770.300 MiB/s 0 succeed, 61073 failed, 0 different pages > > ... > > ok 1 Completed > > > > Remove the HPAGE_SIZE and HPAGE_SHIFT macro. and introduce hpshift() > > helper to get the HPAGE_SHIFT properly. For HPAGE_SIZE, use pre-exist > > Nit : pre-existing Sorry for typo ;) > > > helper, read_pmd_pagesize(). > > > Also, do KSM_MERGE_TIME_HUGE_PAGES test with size of 512 MiB which > > is the LCD pmd_size among 4KB, 16KB and 64KB page_size. > > > > After this patch, output of transhuge-stress: > > > > transhuge-stress: allocate 3817 transhuge pages, using 122146 MiB virtual memory and 119 MiB of ram > > 2.558 s/loop, 0.670 ms/page, 47755.759 MiB/s 2585 succeed, 1232 failed, 2585 different pages > > 2.640 s/loop, 0.692 ms/page, 46268.432 MiB/s 2585 succeed, 1232 failed, 2585 different pages > > 2.635 s/loop, 0.690 ms/page, 46360.298 MiB/s 2585 succeed, 1232 failed, 2585 different pages > > 2.782 s/loop, 0.729 ms/page, 43899.795 MiB/s 2616 succeed, 1201 failed, 2616 different pages > > 2.692 s/loop, 0.705 ms/page, 45380.876 MiB/s 2627 succeed, 1190 failed, 2627 different pages > > 2.612 s/loop, 0.684 ms/page, 46765.812 MiB/s 2628 succeed, 1189 failed, 2628 different pages > > 2.683 s/loop, 0.703 ms/page, 45520.990 MiB/s 2630 succeed, 1187 failed, 2630 different pages > > 2.727 s/loop, 0.714 ms/page, 44789.321 MiB/s 2631 succeed, 1186 failed, 2631 different pages > > ... > > ok 1 Completed > > > > Suggested-by: Lorenzo Stoakes (ARM) > > Signed-off-by: Yeoreum Yun > > --- > > [...] > > > diff --git a/tools/testing/selftests/mm/vm_util.c b/tools/testing/selftests/mm/vm_util.c > > index 4821a3563036..4332f8fb2104 100644 > > --- a/tools/testing/selftests/mm/vm_util.c > > +++ b/tools/testing/selftests/mm/vm_util.c > > @@ -21,6 +21,8 @@ > > > > unsigned int __page_size; > > unsigned int __page_shift; > > +uint64_t __hpage_size; > > +uint64_t __hpage_shift; > > I was wondering, would it make more sense to call these __pmd_pagesize > and __pmd_shift instead? > > hpage_size is used at places for mTHPs of arbitrary sizes and these > values come from read_pmd_pagesize(). So calling __hpage_size as the PMD > size seems a bit weird. Also, there is already a pmd_pagesize variable > in vm_util.c, so I feel the PMD specific names would be more consistent. That seems better. Thanks! -- Sincerely, Yeoreum Yun