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Mon, 20 Jul 2026 14:29:21 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id QIsWI8EwXmrKTQAAD6G6ig (envelope-from ); Mon, 20 Jul 2026 14:29:21 +0000 From: Pedro Falcato To: Andrew Morton , David Hildenbrand , Lorenzo Stoakes Cc: Pedro Falcato , Zi Yan , Baolin Wang , "Liam R. Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Usama Arif , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH 5/8] mm/khugepaged: add kerneldoc to prepare_collapse_file_folio() Date: Mon, 20 Jul 2026 15:29:10 +0100 Message-ID: <20260720142913.846902-6-pfalcato@suse.de> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260720142913.846902-1-pfalcato@suse.de> References: <20260720142913.846902-1-pfalcato@suse.de> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Spam-Flag: NO X-Spam-Score: -6.80 X-Spamd-Result: default: False [-6.80 / 50.00]; REPLY(-4.00)[]; BAYES_HAM(-3.00)[100.00%]; MID_CONTAINS_FROM(1.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000]; R_MISSING_CHARSET(0.50)[]; NEURAL_HAM_SHORT(-0.20)[-0.992]; MIME_GOOD(-0.10)[text/plain]; FUZZY_RATELIMITED(0.00)[rspamd.com]; ARC_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; RCPT_COUNT_TWELVE(0.00)[15]; DKIM_SIGNED(0.00)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; TO_MATCH_ENVRCPT_ALL(0.00)[]; FROM_HAS_DN(0.00)[]; FROM_EQ_ENVFROM(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; RCVD_COUNT_TWO(0.00)[2]; R_RATELIMIT(0.00)[to_ip_from(RL8d8xedm6iu8o66torxsk6bwd)]; TO_DN_SOME(0.00)[]; RCVD_TLS_ALL(0.00)[]; DBL_BLOCKED_OPENRESOLVER(0.00)[imap1.dmz-prg2.suse.org:helo,suse.de:email,suse.de:mid] X-Spam-Level: The input-output expectations are not entirely clear, thus document it. Signed-off-by: Pedro Falcato --- mm/khugepaged.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/mm/khugepaged.c b/mm/khugepaged.c index d170b64378e6..db1f765b6ead 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -2256,6 +2256,21 @@ static struct folio *collapse_read_folio(pgoff_t index, struct collapse_file_sta return folio; } + +/** + * prepare_collapse_file_folio() - Prepare the collapsing of a single file folio + * @index: folio index in the page cache + * @state: helper struct of state being passed back and forth. + * + * prepare_collapse_file_folio() helps prepare the THP collapsing of file folios + * (both shmem and !shmem), including the reading of folios, initial tests for + * dirty/writeback, locking, etc. + * + * Context: Expects @state->mapping->i_pages->xa_lock to be held. Releases the same xa_lock. + * On success, returns a refcounted and locked folio in @state->folio (that may + * not be the same that was passed in). + * Return: Appropriate scan_result value (on success, SCAN_SUCCEED). + */ static enum scan_result prepare_collapse_file_folio(pgoff_t index, struct collapse_file_state *state) { struct address_space *mapping = state->mapping; -- 2.55.0