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 5701E1E5B7E for ; Mon, 21 Apr 2025 16:35:30 +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=1745253331; cv=none; b=cHJpCsNMtfOgC1gMe6AYwB5xELl95A1rueyZP8T9WPzF8a4sDpPv5LreVz5wfZIaqZ+o3PQA7/g/JA2Kr3dtkEVQNzYYSK5a450zl311Adl0Jgm0Sy7tHbMuLvXyZAwbH6fADSls9RpjZw5A/Z0U5eXa6pNW5ri6ntLkgF5XuBY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745253331; c=relaxed/simple; bh=3mFuU2DUGI7GC/f6E3ePt0mrV93b5VvBdvwSVwqYDa4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=RJQDuGDWraI4Rwoz8bGKVlTm5isAiBZp5YsqSQctqzZpuzCYLY3IW3ZnO3T8m1BWkyaYTZx82w+5z56YO+gtlpnvn0fY/zpy173uI4FDKgBORrnG6zMEycNms4P+Q7DLCYtdEpgjpFOZSuzKQ1s2UD+PBWOU2fCL73RPUNrrOIo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=JMMOicHW; 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="JMMOicHW" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1D454C4CEEB; Mon, 21 Apr 2025 16:35:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1745253330; bh=3mFuU2DUGI7GC/f6E3ePt0mrV93b5VvBdvwSVwqYDa4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=JMMOicHWTRtMFJd3ibw5uTk5PRTQKMxdj34sO+hKbQTUywjRYCVPA3H3jjPtGFWgO NPrPJY9vvWd4FSsKYLsVE+XBd+NRdEGUVOIkXPuOeS/Ud2mB5CG7Y4t0yL9qJajp/k 6z1KBciH+0nIs1VGfiz5cW+3HSNHCmbqNFFY2gYCk8voVTM0m+t5bhZaLRIUpcc91N iLfaMJeD1bsgT/EbcRF0xXgpzcCkUjXjtWF+Fr1OTdDeBxtPy12PVzh6X+R80ZNVXM Dlu7QcFhfQhl7QnzT5Z0Kb8opnwDwerWbiCIg/PnpByBM07PusB1/dlsNUvekysMfp JDy8ambtHveiQ== Date: Mon, 21 Apr 2025 19:35:25 +0300 From: Mike Rapoport To: Andrew Morton Cc: Ruihan Li , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] mm/mm_init: Don't iterate pages below ARCH_PFN_OFFSET Message-ID: References: <20250419122801.1752234-1-lrh2000@pku.edu.cn> <20250420135709.732883ee775ad8b41fb668ca@linux-foundation.org> 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: <20250420135709.732883ee775ad8b41fb668ca@linux-foundation.org> On Sun, Apr 20, 2025 at 01:57:09PM -0700, Andrew Morton wrote: > On Sat, 19 Apr 2025 20:28:01 +0800 Ruihan Li wrote: > > > If ARCH_PFN_OFFSET is very large (e.g., something like 2^64-2GiB if the > > kernel is used as a library and loaded at a very high address), the > > pointless iteration for pages below ARCH_PFN_OFFSET will take a very > > long time, and the kernel will look stuck at boot time. > > > > This commit sets the initial value of pfn_hole to ARCH_PFN_OFFSET, which > > avoids the problematic and useless iteration mentioned above. > > > > This problem has existed since commit 907ec5fca3dc ("mm: zero remaining > > unavailable struct pages"). > > > > Signed-off-by: Ruihan Li > > --- > > Link to v1: > > - https://lore.kernel.org/linux-mm/20250418162727.1535335-1-lrh2000@pku.edu.cn/ > > Changes since v1: > > - Removed the unnecessary Fixes tag. > > Why was the Fixes: considered unnecessary? It seems to be useful > information? I didn't think it was important enough for AUTOSEL to pick it. -- Sincerely yours, Mike.