From: Vineet Gupta <vgupta@kernel.org>
To: Zi Yan <ziy@nvidia.com>, Matthew Wilcox <willy@infradead.org>
Cc: linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>,
Geert Uytterhoeven <geert@linux-m68k.org>,
Vlastimil Babka <vbabka@suse.cz>,
David Hildenbrand <david@redhat.com>,
Miaohe Lin <linmiaohe@huawei.com>,
Kefeng Wang <wangkefeng.wang@huawei.com>,
John Hubbard <jhubbard@nvidia.com>,
"Huang, Ying" <ying.huang@intel.com>,
Ryan Roberts <ryan.roberts@arm.com>,
Alexander Potapenko <glider@google.com>,
Kees Cook <keescook@chromium.org>,
linux-kernel@vger.kernel.org,
Geert Uytterhoeven <geert+renesas@glider.be>,
Vineet Gupta <vgupta@kernel.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Subject: Re: [PATCH] mm: use clear_user_(high)page() for arch with special user folio handling
Date: Fri, 6 Dec 2024 09:31:27 -0800 [thread overview]
Message-ID: <bc3b86dd-9bb6-4c6e-b6df-35c687375cde@kernel.org> (raw)
In-Reply-To: <78D4C1B5-3EE7-47F0-A7A2-F1ACFE71CED0@nvidia.com>
On 12/6/24 09:08, Zi Yan wrote:
> On 6 Dec 2024, at 11:42, Matthew Wilcox wrote:
>
>> On Fri, Dec 06, 2024 at 09:19:38AM -0500, Zi Yan wrote:
>>> For architectures setting ARCH_HAS_CPU_CACHE_ALIASING, which requires
>>> flushing cache and arc, which sets folio->flags after clearing a user
>>> folio
>> I think arc just has some legacy code left that needs to be ripped out.
>> See commit d5272aaa8257 which took away ARCH_HAS_CPU_CACHE_ALIASING
>> from arc.
> The PG_dc_clean bit seems not to be related to cache aliasing.
> See commit eacd0e950dc2 ("ARC: [mm] Lazy D-cache flush (non aliasing VIPT)")
Indeed it is not related to aliasing.
>> Looking at 8690bbcf3b70, I wonder if you want to use
>> cpu_dcache_is_aliasing() here?
> Yeah, this is more precise. Will use this in my next version. Thanks.
Commit 8690bbcf3b70 was wrong for ARC as it assumed aliasing is true. The
aliasing D$ code is all gone and cpu_dcache_is_aliasing() is false for ARC now.
-vineet
prev parent reply other threads:[~2024-12-06 17:31 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-12-06 14:19 Zi Yan
2024-12-06 16:42 ` Matthew Wilcox
2024-12-06 17:08 ` Zi Yan
2024-12-06 17:31 ` Vineet Gupta [this message]
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