[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <3747d914-c687-b983-c624-e3418b4d2448@oracle.com>
Date: Tue, 5 Oct 2021 14:28:03 -0700
From: Mike Kravetz <mike.kravetz@...cle.com>
To: Andrew Morton <akpm@...ux-foundation.org>
Cc: linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
Anshuman Khandual <anshuman.khandual@....com>,
Will Deacon <will@...nel.org>,
Mark Rutland <mark.rutland@....com>,
Barry Song <song.bao.hua@...ilicon.com>, stable@...r.kernel.org
Subject: Re: [PATCH] arm64/hugetlb: fix CMA gigantic page order for non-4K
PAGE_SIZE
On 10/5/21 1:54 PM, Andrew Morton wrote:
> On Tue, 5 Oct 2021 13:25:29 -0700 Mike Kravetz <mike.kravetz@...cle.com> wrote:
>
>> For non-4K PAGE_SIZE configs, the largest gigantic huge page size is
>> CONT_PMD_SHIFT order.
>
> What are the user visible effects of this bug?
>
>
Sorry,
I only recently got easy access to arm64 platforms. This is what I saw
as a user:
The largest gigantic huge page size on arm64 with 64K PAGE_SIZE 64K is
16G. Therefore, one should be able to specify 'hugetlb_cma=16G' on the
kernel command line so that 1 gigantic page can be allocated from CMA.
However, when adding such an option the following message is produced:
hugetlb_cma: cma area should be at least 8796093022208 MiB
This is because the calculation for non-4K gigantic page order is
incorrect in the arm64 specific routine arm64_hugetlb_cma_reserve().
Would you like me to send a new version with this in the commit message?
Or, is it easier for you to just add it?
--
Mike Kravetz
Powered by blists - more mailing lists