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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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250420135709.732883ee775ad8b41fb668ca@linux-foundation.org> X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 1ABA4100014 X-Stat-Signature: z67y436o4wu4mir6rswzb39ni4h3teod X-Rspam-User: X-HE-Tag: 1745253331-584772 X-HE-Meta: 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 nhDzUn5t 9orTAMQDZUk8XrTEgKqwPVytxeSXu6comzKh2PN7MGq0gWOJmzdig6H0UYFRRwEl8rrQkwsU/M8arHk0/T74nHNhAwJnj8J88l0Tk0KRtKd0118RKkwrwXhwD6DPMG+th0lLRxeeTaYAGsHPqsDa/LQPJOgbnDvaFZ5mhr6dU65iinDtke6S0nGy7+pbds1FLFpeYR6IqI4ldnP/Qkzd1lU7FDv9wwn2ZIbbkum+E/abftsX6H6TJLXC32yDeT/LyQjiVe5XC0i1Yp13RLd1Bddm4WIOS4MYXMeIi1FMy/d4vV8Ul7WGFX9lkDZFk0c+OWvwm X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: 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.