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b=YUq4OHmUTQCdSYrB/KWNSjzdEckIpS0QhuOSAqLFiZPJVozJMfEJgc+hNFJ50Prsg SoooqX4Y3dJ3DiAeMY7eaIpe+1sqPCFVofjLkHtYQ05U+GCmCpoP7C5NjXbNOeurkf cwEYYCr/JCTdHdXoUWkMfxk7/hioIOrfziL7d4LA1Rn9grHKUAOVpUGZ/Cj5CnRrs2 6aMUbNAI+puutijacp1QvuwBly5D93Y9XI8k/WDC1swxHD3hQDYBi3XCduta+hlwZT 7TNIo+5fEjS1dQkZa1pjYepG8oSSZtHsMNhaWp++nNCeGjePm88zteyZ+iXOfKFzoO Kf1K/NkA3seQA== From: SJ Park To: Cc: SJ Park , Andrew Morton , damon@lists.linux.dev, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [RFC PATCH v2 05/17] mm/damon/core: introduce damon_prep struct Date: Sun, 26 Jul 2026 10:39:21 -0700 Message-ID: <20260726173935.94046-6-sj@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260726173935.94046-1-sj@kernel.org> References: <20260726173935.94046-1-sj@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: E0A5740002 X-Stat-Signature: 38x7pckcnbjk1o3k7chp5wbox6ndhgik X-Rspam-User: X-HE-Tag: 1785087586-759197 X-HE-Meta: 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 nd69T0PL ET6ad3CRK6wiEHePqlVzSKk9uyhEEu+v24pfXDkMrn2S5IyB1RbGVUGHdS+4YbNS/iob5nDkCWzlY2Ao0mH2D5RqZzmT8pjocZvQIbFCf43wK+7COtBR3kUBEKiRpS3j6dtL9mb6OVGIda1hf7vkB8UN/IRI29/cJkOsx0Kj+g5a9FSmnQ2wzCA1V8P3gr+AV+e1O0hEhlwDkZ6cYS3Lnu2ui6sEdCBoYncKe1A/b+6tiuK6LvZ3n1lbQnI5xy0yAJzaByEsmXaFJ9PB7+FLINBZZzg== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Some DAMON probe filter types require preparatory actions. For example, pgilde_unset probe filter can say if the page was accessed but when. To answer the second question, the PG_Idle flag should be set at a specific time. It can make life much easier if DAMON can do such preparatory actions. Introduce a new data type called damon_prep. It specifies each of the preparation actions for each probe. DAMON will execute the action for each region per sampling interval, like it clears page table accessed bits and unsets PG_Idle flag for access monitoring. Also introduce DAMON_PREP_SET_PGIDLE as the initial prep action. As the name says, it will do exactly what DAMON was doing as the preparation action for the access monitoring. Signed-off-by: SJ Park --- include/linux/damon.h | 32 ++++++++++++++++++++++++++++++++ mm/damon/core.c | 26 ++++++++++++++++++++++++++ 2 files changed, 58 insertions(+) diff --git a/include/linux/damon.h b/include/linux/damon.h index cee4b74761081..255b20e44287f 100644 --- a/include/linux/damon.h +++ b/include/linux/damon.h @@ -741,6 +741,27 @@ struct damon_intervals_goal { unsigned long max_sample_us; }; +/** + * enum damon_prep_action - DAMON probing preparation action. + * + * @DAMON_PREP_SET_PGIDLE: Set the probing memory as idle page. + */ +enum damon_prep_action { + DAMON_PREP_SET_PGIDLE, +}; + +/** + * struct damon_prep - DAMON probing preparation request. + * + * @action: Action to do to the probing memory for the preparation. + */ +struct damon_prep { + enum damon_prep_action action; +/* private: */ + /* siblings list. */ + struct list_head list; +}; + /** * enum damon_filter_type - Type of &struct damon_filter * @@ -782,6 +803,8 @@ struct damon_filter { struct damon_probe { unsigned int weight; /* private: */ + /* Preparation actions to apply to each probing memory. */ + struct list_head preps; /* Filters for assessing if a given region is for this probe. */ struct list_head filters; /* Siblings list. */ @@ -961,6 +984,12 @@ static inline unsigned long damon_sz_region(struct damon_region *r) return r->ar.end - r->ar.start; } +#define damon_for_each_prep(p, prep) \ + list_for_each_entry(p, &(prep)->preps, list) + +#define damon_for_each_prep_safe(p, next, prep) \ + list_for_each_entry_safe(p, next, &(prep)->preps, list) + #define damon_for_each_filter(f, p) \ list_for_each_entry(f, &(p)->filters, list) @@ -1014,6 +1043,9 @@ static inline unsigned long damon_sz_region(struct damon_region *r) #ifdef CONFIG_DAMON +struct damon_prep *damon_new_prep(enum damon_prep_action action); +void damon_add_prep(struct damon_probe *p, struct damon_prep *prep); + struct damon_filter *damon_new_filter(enum damon_filter_type type, bool matching, bool allow); void damon_add_filter(struct damon_probe *probe, struct damon_filter *f); diff --git a/mm/damon/core.c b/mm/damon/core.c index 5eb0400d5ce16..bda61f9ec0266 100644 --- a/mm/damon/core.c +++ b/mm/damon/core.c @@ -111,6 +111,28 @@ int damon_select_ops(struct damon_ctx *ctx, enum damon_ops_id id) return err; } +struct damon_prep *damon_new_prep(enum damon_prep_action action) +{ + struct damon_prep *prep; + + prep = kmalloc_obj(*prep); + if (!prep) + return NULL; + prep->action = action; + INIT_LIST_HEAD(&prep->list); + return prep; +} + +void damon_add_prep(struct damon_probe *p, struct damon_prep *prep) +{ + list_add_tail(&prep->list, &p->preps); +} + +static void damon_free_prep(struct damon_prep *p) +{ + kfree(p); +} + struct damon_filter *damon_new_filter(enum damon_filter_type type, bool matching, bool allow) { @@ -167,6 +189,7 @@ struct damon_probe *damon_new_probe(void) if (!p) return NULL; p->weight = 0; + INIT_LIST_HEAD(&p->preps); INIT_LIST_HEAD(&p->filters); INIT_LIST_HEAD(&p->list); return p; @@ -184,8 +207,11 @@ static void damon_del_probe(struct damon_probe *p) static void damon_free_probe(struct damon_probe *p) { + struct damon_prep *prep, *prep_next; struct damon_filter *f, *next; + damon_for_each_prep_safe(prep, prep_next, p) + damon_free_prep(prep); damon_for_each_filter_safe(f, next, p) damon_free_filter(f); kfree(p); -- 2.47.3