From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B51F33803C6; Thu, 6 Aug 2026 13:45:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786023932; cv=none; b=qe2D6VmaZR+WEZIYtggWCOIoeN5ez3TZgrOQBMsORnEGeIK003EYVAcky1PAB8w+9WA+Yc41RwDAHIXloFEnwCNsxXJEkFDQJi+Lfq2xcS2SmKd7WggZDEgn5tbE/ZDQwNKnGQfgBt99u9+iiw4GvlaMux8lUJlutMCSfFA66qg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786023932; c=relaxed/simple; bh=t+iINagZCvzAKPavgvUGNvNcY9/wQ/Y+4XLUuKp7igM=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=rFqKBq9D9rny4HHZlkUgaMpE0YBTGlGp7WNxb5ezZztEDZQgDeA9gJkFEYtDXOavjfDvkbOPboeDjdcxqpupy4XDuWyzXQ8par2O+cwpbGdnPtzVBuzieUAnwbOfZcnOYiRc9ploF8PUx5YCPafY/Wx+RmKioGXLkC3D9fcWmHk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=eQpFARiz; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="eQpFARiz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7C4721F000E9; Thu, 6 Aug 2026 13:45:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1786023931; bh=jAk1Hr6s5yQyhKhExTE18XybtKCeypABPp+ECDjJHbQ=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=eQpFARizBXLOyawJDeTwY/7/bSx37TLPm4JfgEQNEFHdUJxHWtTJ9GeyZj5uaYXuS 3VCCxLZMzaGJvI60f6tEPJy4UrBWR0uZP6vYoVa5aQzAYtDIpO6DRSRcQg6z8gGe9I 5E8DELbmr4yEp2URNXIS11Hf8ZSJEOexSwHnFHGQrvr4TAaN6rEfHEvCP7Zhhiu1hF xIFddw+EOJwi18jUHIBfhOXdYQ+ERqgGRV/2+Fhn1UMVUprHAtF0Y8WlgP5qNFffTi D2uIcyE2qm/JT74T/RdnouOijb+TqokwIbDfbnCVxjfDDuCH4xM19W0ESbXilm+/PZ eMEJbVARO5SQw== Message-ID: <9d0d98ea-05bd-43c0-bb36-68aea62cbde8@kernel.org> Date: Thu, 6 Aug 2026 15:45:27 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] selftests/mm: khugepaged: skip swap tests when no swap available To: Alexander Gordeev , Andrew Morton , Lorenzo Stoakes Cc: linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org References: <20260804125351.1715708-1-agordeev@linux.ibm.com> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 8/4/26 14:53, Alexander Gordeev wrote: > When no swap is configured, swap-related tests fail because > madvise(MADV_PAGEOUT) does not swap out pages. Add a helper > function to detect swap availability and skip these tests. You should mention what the effect of that is. > > Signed-off-by: Alexander Gordeev > --- > tools/testing/selftests/mm/khugepaged.c | 33 +++++++++++++++++++++++++ > 1 file changed, 33 insertions(+) > > diff --git a/tools/testing/selftests/mm/khugepaged.c b/tools/testing/selftests/mm/khugepaged.c > index 10e8dedcb087..b254baf9e0b7 100644 > --- a/tools/testing/selftests/mm/khugepaged.c > +++ b/tools/testing/selftests/mm/khugepaged.c > @@ -216,6 +216,25 @@ static bool check_swap(void *addr, unsigned long size) > return swap; > } > > +static bool is_swap_available(unsigned long size) > +{ > + unsigned long swap_total = 0; > + char buffer[256]; > + FILE *fp; > + > + fp = fopen("/proc/meminfo", "r"); > + if (!fp) > + return false; > + > + while (fgets(buffer, sizeof(buffer), fp)) { > + if (sscanf(buffer, "SwapTotal: %lu kB", &swap_total) == 1) > + break; > + } > + fclose(fp); > + > + return swap_total >= (size / 1024); > +} > + > static void *alloc_mapping(int nr) > { > void *p; > @@ -734,6 +753,13 @@ static void collapse_swapin_single_pte(struct collapse_context *c, struct mem_op > { > void *p; > > + if (!is_swap_available(page_size)) { > + ksft_print_msg("No swap available..."); > + skip("Skip"); > + ksft_test_result_skip("%s\n", __func__); > + return; > + } > + > p = ops->setup_area(1); > ops->fault(p, 0, hpage_pmd_size); > > @@ -760,6 +786,13 @@ static void collapse_max_ptes_swap(struct collapse_context *c, struct mem_ops *o > int max_ptes_swap = thp_read_num("khugepaged/max_ptes_swap"); > void *p; > > + if (!is_swap_available((max_ptes_swap + 1) * page_size)) { > + ksft_print_msg("No swap available..."); > + skip("Skip"); > + ksft_test_result_skip("%s\n", __func__); > + return; > + } > + > p = ops->setup_area(1); > ops->fault(p, 0, hpage_pmd_size); > See https://lore.kernel.org/all/20260715133418.170386-1-jaeyeon.lee.dev@gmail.com/ where I raise that we should rather handle the actual MADV_PAGEOUT errors, because there can be other reasons why MADV_PAGEOUT just fails. -- Cheers, David