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 A8564340A6B; Tue, 13 Oct 2026 10:14:12 +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=1791886454; cv=none; b=gSdHZw6YDNgS3/niHtrsGRL4l7u9APzx8ojVRrK0UPOasLRpuwA0rY8jdHHI4r8cuSWALP17FehdvA/OEDYxXzwgsdCqRhh+8Z3qVt8rwjBezscPy/AfJ+TYTqmgAEC0eiDU9KSM/HR0EDaHHAyrWsGDivWITxLMc/VIxbSVpgs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791886454; c=relaxed/simple; bh=CwIINxwYMx735E6F8s9ep3Xem7KHZ4ZBlh/HyIgAbgg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=unzBtXx32uSq1vdCr4JPrEpmEEeHdTeANrVMkiYc6pym7ere0ySPNk/CE2GEagPnzgCJWWGiDeJuaAP2cfs0IZ7N4pINXgRdyACqZdnke9dHEr0VfzxCvE8mJUoiJiH6YHdRyhYBV6rtAsAkoKQsZRwrCQub+44mvcMKPD0DyHA= 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=EwlAFwkD; 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="EwlAFwkD" 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 D2D21169C; Tue, 13 Oct 2026 03:14:08 -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 75FB13F7B4; Tue, 13 Oct 2026 03:14:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1791886452; bh=CwIINxwYMx735E6F8s9ep3Xem7KHZ4ZBlh/HyIgAbgg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=EwlAFwkDH3DXPIhTH/r3Gq7gzfPEvks0fkmwjKTIIEU8lU7V9m+CEaFGUJ2qIKkcH LBg1oIHubi4Bc3NZ0+tI90c3UVa78sskD/3IZOdXFNrnVPDx4Ice2OAwYQT3Uerlxg RYruN74ALtEB3aq/oz+lABH3jelhu/OBkGnIJslI= Date: Tue, 13 Oct 2026 11:14:05 +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 v6 2/3] kselftest: mm: remove HPAGE_SIZE and HPAGE_SHIFT macro Message-ID: References: <20261013-fix_hpage_macro-v6-0-2c52d0484de3@arm.com> <20261013-fix_hpage_macro-v6-2-2c52d0484de3@arm.com> <40f95078-4d3c-48da-9262-afadf231014f@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: <40f95078-4d3c-48da-9262-afadf231014f@arm.com> On Tue, Oct 13, 2026 at 03:26:40PM +0530, Sarthak Sharma wrote: > Hi Yeoreum! > > On 10/13/26 3:16 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) > > Tested-by: Sarthak Sharma > > Reviewed-by: Zi Yan > > Reviewed-by: Sarthak Sharma > > Signed-off-by: Yeoreum Yun > > --- > > [...] > > > diff --git a/tools/testing/selftests/mm/vm_util.c b/tools/testing/selftests/mm/vm_util.c > > index 5f2fb5b819c4a..efd99298be135 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 __pmd_psize = -1ull; > > +uint64_t __pmd_pshift = -1ull; > > > > uint64_t pagemap_get_entry(int fd, char *start) > > { > > @@ -161,19 +163,40 @@ uint64_t pmd_psize(void) > > char buf[20]; > > ssize_t num_read; > > > > + if (__pmd_psize != -1ull) > > + return __pmd_psize; > > + > > fd = open(PMD_SIZE_FILE_PATH, O_RDONLY); > > - if (fd == -1) > > + if (fd == -1) { > > + __pmd_psize = 0; > > return 0; > > + } > > > > num_read = read(fd, buf, 19); > > if (num_read < 1) { > > + __pmd_psize = 0; > > close(fd); > > return 0; > > } > > buf[num_read] = '\0'; > > close(fd); > > > > - return strtoul(buf, NULL, 10); > > + __pmd_psize = strtoul(buf, NULL, 10); > > + > > + return __pmd_psize; > > +} > > + > > +uint64_t pmd_pshift(void) > > +{ > > + if (__pmd_pshift != -1ull) > > + return __pmd_pshift; > > + > > + if (__pmd_psize != -1ull) > > + __pmd_psize = pmd_psize(); > > Kiryl pointed this out in v5 [1], you might have missed it. This check > seems to be inverted. > > [1] https://lore.kernel.org/all/asj4dT2Q__SlKhgr@thinkstation/ Oh. Thanks. I've missed. -- Sincerely, Yeoreum Yun