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charset=us-ascii Content-Disposition: inline In-Reply-To: <2e2d3f51-34e3-4982-b982-ab7b555cba21@redhat.com> X-Rspamd-Queue-Id: 4BDEA14001B X-Rspam-User: X-Rspamd-Server: rspam04 X-Stat-Signature: 9x3r1r9ctuor74ioenxwnp6nhgop8c3d X-HE-Tag: 1701191888-188682 X-HE-Meta: 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 39LYWeOY vASXju9vfAyRg+A32hEk+TvIPR6oK1j6x5zvOX8ncHOAxXbBRuMi/3xBNW6VMOA9LWjjHCVoofzpf6TPBH9CsakTAUZcRba3/TSbfljQiLwNMBhD/vbF9ATtTfPTc2SCjKoTaQAD+nFt6hsz+VB+OpbXGIw== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Hi, On Tue, Nov 28, 2023 at 05:58:55PM +0100, David Hildenbrand wrote: > On 27.11.23 14:03, Alexandru Elisei wrote: > > Hi, > > > > On Fri, Nov 24, 2023 at 08:36:52PM +0100, David Hildenbrand wrote: > > > On 19.11.23 17:57, Alexandru Elisei wrote: > > > > Add arch_free_pages_prepare() hook that is called before that page flags > > > > are cleared. This will be used by arm64 when explicit management of tag > > > > storage pages is enabled. > > > > > > Can you elaborate a bit what exactly will be done by that code with that > > > information? > > > > Of course. > > > > The MTE code that is in the kernel today uses the PG_arch_2 page flag, which it > > renames to PG_mte_tagged, to track if a page has been mapped with tagging > > enabled. That flag is cleared by free_pages_prepare() when it does: > > > > page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP; > > > > When tag storage management is enabled, tag storage is reserved for a page if > > and only if the page is mapped as tagged. When a page is freed, the code looks > > at the PG_mte_tagged flag to determine if the page was mapped as tagged, and > > therefore has tag storage reserved, to determine if the corresponding tag > > storage should also be freed. > > > > I have considered using arch_free_page(), but free_pages_prepare() calls the > > function after the flags are cleared. > > > > Does that answer your question? > > Yes, please add some of that to the patch description! Will do! Thanks, Alex > > -- > Cheers, > > David / dhildenb >