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Date: Thu, 10 Sep 2026 14:52:07 +0100
From: Yeoreum Yun <yeoreum.yun@arm.com>
To: "David Hildenbrand (Arm)" <david@kernel.org>
Cc: Yeoreum Yun <yeoreum.yun@arm.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Lorenzo Stoakes <ljs@kernel.org>, Zi Yan <ziy@nvidia.com>,
	Baolin Wang <baolin.wang@linux.alibaba.com>,
	"Liam R. Howlett" <liam@infradead.org>,
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	Barry Song <baohua@kernel.org>, Lance Yang <lance.yang@linux.dev>,
	Usama Arif <usama.arif@linux.dev>,
	Vlastimil Babka <vbabka@kernel.org>,
	Mike Rapoport <rppt@kernel.org>,
	Suren Baghdasaryan <surenb@google.com>,
	Michal Hocko <mhocko@suse.com>, Shuah Khan <shuah@kernel.org>,
	Kevin Brodsky <kevin.brodsky@arm.com>, linux-mm@kvack.org,
	linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: ;, Re: ;, [PATCH v5 3/3] kselftest: ;, mm:
 introducealloc_isolated_mem;
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In-Reply-To: <8d27168e-5443-4073-bc65-24ddbe32e29a@kernel.org>

On Thu, Sep 10, 2026 at 03:14:36PM +0200, David Hildenbrand (Arm) wrote:
> On 9/10/26 14:34, Yeoreum Yun wrote:
> > On Thu, Sep 10, 2026 at 02:25:40PM +0200, David Hildenbrand (Arm) wrote:
> >> On 9/10/26 14:16, Yeoreum Yun wrote:
> >>>
> >>> True. I overlooked guard bit is sticky.
> >>>
> >>>
> >>> It's enough but alloc_isolated_mem() could be modified to allocate with
> >>> PROT_NONE first and then change the prot.
> >>>
> >>> It seems whether make a helper or testcase should write the code
> >>> properly in case of unwanted VMA merge.
> >>>
> >>> IMHO, instead of testcase write them all
> >>
> >> So far I am aware of exactly one test case, which others do absolutely need this?
> > 
> > True. I'll respin with your suggestion.
> 
> Don't get me wrong, if we'll need this for other tests we can add helpers. But
> for a single user adding a helper is not really worth it.

No worries. Since I thought there is no use case right now except the
test, I've agreed.

Thanks!


-- 
Sincerely,
Yeoreum Yun