From: "Yin, Fengwei" <fengwei.yin@intel.com>
To: Ram Tummala <rtummala@nvidia.com>, <akpm@linux-foundation.org>
Cc: <willy@infradead.org>, <linux-mm@kvack.org>,
<linux-kernel@vger.kernel.org>, <apopple@nvidia.com>,
<stable@vger.kernel.org>
Subject: Re: [PATCH] mm: Fix PTE_AF handling in fault path on architectures with HW AF support
Date: Wed, 10 Jul 2024 09:08:13 +0800 [thread overview]
Message-ID: <d1ea4228-9ee0-41de-9119-e9a8a577ca51@intel.com> (raw)
In-Reply-To: <20240710000942.623704-1-rtummala@nvidia.com>
On 7/10/2024 8:09 AM, Ram Tummala wrote:
> The polarity of prefault calculation is incorrect. This leads to prefault
> being incorrectly set for the faulting address. The following if check will
> incorrectly clear the PTE_AF bit instead of setting it and the access will
> fault again on the same address due to the missing PTE_AF bit.
>
> if (prefault && arch_wants_old_prefaulted_pte())
> entry = pte_mkold(entry);
I have same confusion as Matthew about the PTE_AF.
But I think this is a good catch as old code is like:
bool prefault = vmf->address != addr;
Sorry for the issue by me. And
Reviewed-by: Yin Fengwei <fengwei.yin@intel.com>
Regards
Yin, Fengwei
next prev parent reply other threads:[~2024-07-10 1:08 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-07-10 0:09 Ram Tummala
2024-07-10 0:13 ` Matthew Wilcox
2024-07-10 1:02 ` Alistair Popple
2024-07-10 1:08 ` Yin, Fengwei [this message]
2024-07-10 4:07 ` David Hildenbrand
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