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 949493C1991; Tue, 13 Oct 2026 14:11:40 +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=1791900702; cv=none; b=VzZPqDfFsIZDo7z077GbwyPyIvTLgI6Kn9767V/FGYWgKpuFFXMKnHFnNlvBeoMSl/nGor9FAsBK3q3mCpX40W/uKXs2Q+l4/0F35hcgTid/YiYTegAWaTVbdusM04CONIhqN04UhqskgBlWdPQX9rblrzSCvpbBVWOI2C5iR58= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791900702; c=relaxed/simple; bh=d/DaViX6waQjEqKz+BRXBRyPDQzNzOaSHBwWJqd0NxU=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=RXQspUCiz0fhhXcP5VqPCunFam8B2bpDyy8Tfqk9yjYpa12J1uQTTLEpxy+2dQtky4TIK25QeoEgEB0u7HL3nmky6ib8WVcjwapRC2T7BVSpUKeuODwULnMdpn9/gg7Iagy5a1zTbOagJTTohhjJRtRreh/k2GfvrhAGSxYh/X0= 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=COwDhIpl; 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="COwDhIpl" 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 4EE65169E; Tue, 13 Oct 2026 07:11:36 -0700 (PDT) Received: from e129823.arm.com (unknown [10.2.213.3]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 77F1F3F7B4; Tue, 13 Oct 2026 07:11:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1791900699; bh=d/DaViX6waQjEqKz+BRXBRyPDQzNzOaSHBwWJqd0NxU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=COwDhIplXug+N3BUuVPymIIemCYgZM0nKYl9fW62zWUEPhoodm3dfc3SR2KbznwZQ bp/+qoTUhaPqE9NjEKwpjEc//4nUaIr178J2towXpIWOLnN8fLkTRXjv8G42EAfYfG HNOM35+vziAgrZiRfnh7+ikSiq9x0SsbfOk0c7qs= Date: Tue, 13 Oct 2026 15:11:27 +0100 From: Yeoreum Yun To: Sarthak Sharma Cc: Yeoreum Yun , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Zi Yan , Baolin Wang , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Usama Arif , Kiryl Shutsemau , Peter Xu , linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, Andrew Morton , David Hildenbrand , Shuah Khan , Jason Gunthorpe , Leon Romanovsky Subject: Re: [PATCH v7 2/3] kselftest: mm: remove HPAGE_SIZE and HPAGE_SHIFT macro Message-ID: References: <20261013-fix_hpage_macro-v7-0-3d77129e0557@arm.com> <20261013-fix_hpage_macro-v7-2-3d77129e0557@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@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: > Hi Yeoreum! > > On 10/13/26 4:07 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 then 4KB. > > > > Here is the 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 pmd_pshift() > > helper to get the HPAGE_SHIFT properly. For HPAGE_SIZE, use pre-existing > > helper, pmd_psize(). > > > > Also, run the KSM_MERGE_TIME_HUGE_PAGES test with a size of 512 MiB, > > which is the least common multiple of the PMD sizes for 4 KiB, 16 KiB, > > and 64 KiB base pages. Since allocate_transhuge() allocates mappings in > > PMD-sized units, the test may fail with the previous size of 100 MiB, > > which is not a multiple of the PMD size when the base page size is > > 16 KiB or 64 KiB. > > > > 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 > > --- > > tools/testing/selftests/mm/guard-regions.c | 10 +++++-- > > tools/testing/selftests/mm/ksm_tests.c | 16 ++++++----- > > tools/testing/selftests/mm/run_vmtests.sh | 4 +-- > > tools/testing/selftests/mm/transhuge-stress.c | 25 +++++++++++------- > > tools/testing/selftests/mm/vm_util.c | 38 +++++++++++++++++++++++---- > > tools/testing/selftests/mm/vm_util.h | 9 +++---- > > 6 files changed, 71 insertions(+), 31 deletions(-) > > > > diff --git a/tools/testing/selftests/mm/guard-regions.c b/tools/testing/selftests/mm/guard-regions.c > > index f7d53ea3c2527..02f69244f9a42 100644 > > --- a/tools/testing/selftests/mm/guard-regions.c > > +++ b/tools/testing/selftests/mm/guard-regions.c > > @@ -2194,14 +2194,20 @@ TEST_F(guard_regions, pagemap_scan) > > TEST_F(guard_regions, collapse) > > { > > const unsigned long page_size = self->page_size; > > - const unsigned long size = 2 * HPAGE_SIZE; > > - const unsigned long num_pages = size / page_size; > > + const uint64_t hpage_size = pmd_psize(); > > + unsigned long size, num_pages; > > char *ptr; > > int i; > > > > if (!thp_available()) > > SKIP(return, "Transparent Hugepages not available\n"); > > > > + if (!hpage_size) > > + ksft_exit_fail_msg("reading hpage_size failed\n"); > > I'm sorry for not catching this earlier, but I don't think calling a > ksft_exit_fail_msg() for not being able to calculate PMD size is a good > idea. Maybe call an ASSERT*() here, something like > > ASSERT_NE(hpage_size, 0); > > so that just this test fails, instead of the whole run exiting with a > bail out? No. The failure would occur if open() or read() fails, and subsequent attempts would likely fail for the same reason. This is also why __pmd_size is set to 0 after a failed attempt. We don't need to produce useless failure log anymore. [...snip...] -- Sincerely, Yeoreum Yun