From: Andrew Morton <akpm@linux-foundation.org>
To: Jia He <hejianet@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>,
Minchan Kim <minchan@kernel.org>,
Claudio Imbrenda <imbrenda@linux.vnet.ibm.com>,
Arvind Yadav <arvind.yadav.cs@gmail.com>,
Mike Rapoport <rppt@linux.vnet.ibm.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
jia.he@hxt-semitech.com, Hugh Dickins <hughd@google.com>
Subject: Re: [PATCH v2] mm/ksm: ignore STABLE_FLAG of rmap_item->address in rmap_walk_ksm
Date: Wed, 9 May 2018 16:31:01 -0700 [thread overview]
Message-ID: <20180509163101.02f23de1842a822c61fc68ff@linux-foundation.org> (raw)
In-Reply-To: <1525403506-6750-1-git-send-email-hejianet@gmail.com>
On Fri, 4 May 2018 11:11:46 +0800 Jia He <hejianet@gmail.com> wrote:
> In our armv8a server(QDF2400), I noticed lots of WARN_ON caused by PAGE_SIZE
> unaligned for rmap_item->address under memory pressure tests(start 20 guests
> and run memhog in the host).
>
> ...
>
> In rmap_walk_ksm, the rmap_item->address might still have the STABLE_FLAG,
> then the start and end in handle_hva_to_gpa might not be PAGE_SIZE aligned.
> Thus it will cause exceptions in handle_hva_to_gpa on arm64.
>
> This patch fixes it by ignoring(not removing) the low bits of address when
> doing rmap_walk_ksm.
>
> Signed-off-by: jia.he@hxt-semitech.com
I assumed you wanted this patch to be committed as
From:jia.he@hxt-semitech.com rather than From:hejianet@gmail.com, so I
made that change. Please let me know if this was inappropriate.
You can do this yourself by adding an explicit From: line to the very
start of the patch's email text.
Also, a storm of WARN_ONs is pretty poor behaviour. Is that the only
misbehaviour which this bug causes? Do you think the fix should be
backported into earlier kernels?
next prev parent reply other threads:[~2018-05-09 23:31 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-03 8:34 [PATCH] mm/ksm: ignore STABLE_FLAG of rmap_item->address in rmap_walk_ksm Jia He
2018-05-03 10:44 ` Claudio Imbrenda
2018-05-03 13:23 ` Jia He
2018-05-04 3:11 ` [PATCH v2] " Jia He
2018-05-04 5:56 ` Jia He
2018-05-09 23:31 ` Andrew Morton [this message]
2018-05-10 1:26 ` Jia He
2018-05-14 9:09 ` Suzuki K Poulose
2018-05-14 9:45 ` Suzuki K Poulose
2018-05-24 8:44 ` Suzuki K Poulose
[not found] ` <198fe48c-0d26-7dd1-89dc-415bd3c7ab41@gmail.com>
2018-05-24 9:01 ` Suzuki K Poulose
2018-05-24 9:36 ` Jia He
2018-05-24 20:38 ` Andrew Morton
2018-06-07 22:13 ` Andrew Morton
2018-06-07 23:38 ` Andrea Arcangeli
2018-06-08 1:32 ` Jia He
2018-06-08 1:23 ` Jia He
2018-06-08 11:08 ` Suzuki K Poulose
2018-05-03 13:41 ` [PATCH] " Michal Hocko
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