From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 EEA3533DEF5 for ; Tue, 27 Jan 2026 10:30:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769509807; cv=none; b=u1OzN5ziIDT1nHEb7V0zJar5fw5RH/Sv3XNqJYlbMFzFE/SfzfGwl+AY4KMLlNy6VrYt4yAxL5yufDoSAuXuVdZLpst82uuBlCqlkWJgb+fBBpmY7ufnMaOjMCX69FIrX4XOGPvhA8ihQnC/yN1r9+7gp+w9i8jAj39+1wZjxqQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769509807; c=relaxed/simple; bh=dhHYsR9fUk6WUXJbc6tT1GAuFjFws3soA5OGepqX/5s=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=K80EYE7agQIczXbvzQ/9opLvmCRZvW993m5w91DA12zgxlvrE88/bXaB1etvVgrKQmdfN4N7zpArTjbtkqATyYEvxBNMTbgUtzBRBdyRd4ENW6LEqEBRvlicbOLBiPh1ReoLeKKuhUhzpD9sO7MjOlruyfgkG1Q7Kr2fCANPxgc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Ly53+/g7; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Ly53+/g7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 87EA7C116C6; Tue, 27 Jan 2026 10:30:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1769509806; bh=dhHYsR9fUk6WUXJbc6tT1GAuFjFws3soA5OGepqX/5s=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=Ly53+/g7GMKrioxrpvJKQ30gqvhpgJ/NdJQ7qcRscTsNHlxgdg4WEB2L9LgRliowd w+NGXbw+kK3vzBPhrespO4uxHBuegqjslVshEnpEaPuYiatuUmgE4iZ4AIWo7PYn/x uS5OSYJ0KJKkKvBK6Qnhfn1GZslHwCGR6/fzUvRb98D3xXlEFdfgK5BCEZOpnJI9X8 UYONAGVvGiKzO2T3b6A09yd1f81uRAKpSKqgXF+JocsuxmuW+zUcjFBEvUGz8YqB2r o0OwySAR3zU6N8doTj/MqORWAa7sKhWS7myvc+ga7O7KgYBUaS8sL1Yz4tdr2HfJQB T1K634E3AjC3A== Message-ID: Date: Tue, 27 Jan 2026 11:29:58 +0100 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] mm: folio_zero_user: open code range computation in folio_zero_user() To: Ankur Arora , linux-kernel@vger.kernel.org, linux-mm@kvack.org, x86@kernel.org Cc: akpm@linux-foundation.org, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, mingo@redhat.com, mjguzik@gmail.com, luto@kernel.org, peterz@infradead.org, tglx@linutronix.de, willy@infradead.org, raghavendra.kt@amd.com, chleroy@kernel.org, ioworker0@gmail.com, lizhe.67@bytedance.com, boris.ostrovsky@oracle.com, konrad.wilk@oracle.com, kernel test robot References: <20260107072009.1615991-9-ankur.a.arora@oracle.com> <20260126183212.2366596-1-ankur.a.arora@oracle.com> From: "David Hildenbrand (Red Hat)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 1/26/26 19:32, Ankur Arora wrote: > riscv64-gcc-linux-gnu (v8.5) reports a compile time assert in: > > r[2] = DEFINE_RANGE(clamp_t(s64, fault_idx - radius, pg.start, pg.end), > clamp_t(s64, fault_idx + radius, pg.start, pg.end)); > > where it decides that pg.start > pg.end in: > clamp_t(s64, fault_idx + radius, pg.start, pg.end)); > > where pg comes from: > const struct range pg = DEFINE_RANGE(0, folio_nr_pages(folio) - 1); > > That does not seem like it could be true. Even for pg.start == pg.end, > we would need folio_test_large() to evaluate to false at compile time: > > static inline unsigned long folio_nr_pages(const struct folio *folio) > { > if (!folio_test_large(folio)) > return 1; > return folio_large_nr_pages(folio); > } > > Workaround by open coding the range computation. Also, simplify the type > declarations for the relevant variables. > > Reported-by: kernel test robot > Closes: https://lore.kernel.org/oe-kbuild-all/202601240453.QCjgGdJa-lkp@intel.com/ > Signed-off-by: Ankur Arora > --- > > Hi Andrew > > I'm not certain about linux-next rebasing protocol, but I'm guessing > this patch will be squashed in patch-8 ("mm: folio_zero_user: cache > neighbouring pages"). > > The commit message doesn't contain anything needing preserving if it is. > > Thanks > Ankur > > mm/memory.c | 23 +++++++++++------------ > 1 file changed, 11 insertions(+), 12 deletions(-) > > diff --git a/mm/memory.c b/mm/memory.c > index ce933ee4a3dd..e49340f51fa9 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -7282,30 +7282,29 @@ static void clear_contig_highpages(struct page *page, unsigned long addr, > void folio_zero_user(struct folio *folio, unsigned long addr_hint) > { > const unsigned long base_addr = ALIGN_DOWN(addr_hint, folio_size(folio)); > - const long fault_idx = (addr_hint - base_addr) / PAGE_SIZE; > const struct range pg = DEFINE_RANGE(0, folio_nr_pages(folio) - 1); > - const int radius = FOLIO_ZERO_LOCALITY_RADIUS; > + const long fault_idx = (addr_hint - base_addr) / PAGE_SIZE; > + const long radius = FOLIO_ZERO_LOCALITY_RADIUS; > struct range r[3]; > int i; > > /* > - * Faulting page and its immediate neighbourhood. Will be cleared at the > - * end to keep its cachelines hot. > + * Faulting page and its immediate neighbourhood. Cleared at the end to > + * keep its cachelines hot. > */ Why are there rather unrelated changes in this patch? Like this comment change, or the movement of "fualt_idx" declaration above? -- Cheers David