From patchwork Mon Jan 15 04:52:50 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Honggyu Kim X-Patchwork-Id: 13519314 Received: from invmail4.hynix.com (exvmail4.skhynix.com [166.125.252.92]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 42B3323CC; Mon, 15 Jan 2024 04:53:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=sk.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sk.com X-AuditID: a67dfc5b-d6dff70000001748-5f-65a4ba2e01d2 From: Honggyu Kim To: sj@kernel.org, damon@lists.linux.dev, linux-mm@kvack.org Cc: linux-trace-kernel@vger.kernel.org, linux-kernel@vger.kernel.org, kernel_team@skhynix.com, akpm@linux-foundation.org, apopple@nvidia.com, baolin.wang@linux.alibaba.com, dave.jiang@intel.com, linmiaohe@huawei.com, lizhijian@cn.fujitsu.com, mathieu.desnoyers@efficios.com, mhiramat@kernel.org, rostedt@goodmis.org, surenb@google.com, yangx.jy@fujitsu.com, ying.huang@intel.com, ziy@nvidia.com, Honggyu Kim Subject: [RFC PATCH 2/4] mm/damon: introduce DAMOS_DEMOTE action for demotion Date: Mon, 15 Jan 2024 13:52:50 +0900 Message-ID: <20240115045253.1775-3-honggyu.kim@sk.com> X-Mailer: git-send-email 2.43.0.windows.1 In-Reply-To: <20240115045253.1775-1-honggyu.kim@sk.com> References: <20240115045253.1775-1-honggyu.kim@sk.com> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFprPIsWRmVeSWpSXmKPExsXC9ZZnoa7eriWpBu3/TC3mrF/DZrHrRojF /73HGC2e/P/NanHiZiObRef3pSwWl3fNYbO4t+Y/q8WR9WdZLNbdArI2nz3DbLF4uZrFvo4H TBaHv75hsph8aQGbxYspZxgtTs6azGIx++g9dgchj/8HJzF7LD39hs1jQxOQaNl3i91jwaZS j5Yjb1k9Fu95yeSxaVUnm8emT5PYPU7M+M3isfOhpceLzTMZPXqb37F5fN4kF8AXxWWTkpqT WZZapG+XwJXxZ9lB5oIFdhVbVr9hamBsMO5i5OSQEDCR6Py4iK2LkQPMbp6RChJmE1CTuPJy EhNIWETAQWLVV4UuRi4OZoEzzBLNvZdZQGqEBXwlJm1ZAWazCKhKnD7wmR3E5hUwk1jYco0N YrymxOPtP8HinALmEq/b3zCD2EJANY1rv0HVC0qcnPkEbA6zgLxE89bZzCDLJAQ2sUu0f//B DDFIUuLgihssExj5ZyHpmYWkZwEj0ypGocy8stzEzBwTvYzKvMwKveT83E2MwGhbVvsnegfj pwvBhxgFOBiVeHh//F2cKsSaWFZcmXuIUYKDWUmE9+DzBalCvCmJlVWpRfnxRaU5qcWHGKU5 WJTEeY2+lacICaQnlqRmp6YWpBbBZJk4OKUaGAPNeW/+9StzX5VhuWrp8zO7+HanabQkBfoe +7nEoF1qxi7lP55Vh8TWcsWG9QrGqyXaRl/k29IY2Vy9JSprRQJbk/LTTUIWFtnMO50/xyv/ T84zO1Fu4fO66jm3nxbPCfvTl5ZvuM/1JyBlv8ikZ97v/a8beH5f07bvbtvFym3JvflHDt3W U2Ipzkg01GIuKk4EAG2hjDqyAgAA X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFupnkeLIzCtJLcpLzFFi42LhmqGlp6u3a0mqwed76hZz1q9hs9h1I8Ti /95jjBZP/v9mtThxs5HN4vOz18wWh+eeZLXo/L6UxeLyrjlsFvfW/Ge1OLL+LIvFultA1uaz Z5gtFi9Xs9jX8YDJ4vDXN0wWky8tYLN4MeUMo8XJWZNZLGYfvcfuIOLx/+AkZo+lp9+weWxo AhIt+26xeyzYVOrRcuQtq8fiPS+ZPDat6mTz2PRpErvHiRm/WTx2PrT0eLF5JqNHb/M7No9v tz08Fr/4wOTxeZNcgEAUl01Kak5mWWqRvl0CV8afZQeZCxbYVWxZ/YapgbHBuIuRg0NCwESi eUZqFyMnB5uAmsSVl5OYQMIiAg4Sq74qdDFycTALnGGWaO69zAJSIyzgKzFpywowm0VAVeL0 gc/sIDavgJnEwpZrbCC2hICmxOPtP8HinALmEq/b3zCD2EJANY1rv0HVC0qcnPkEbA6zgLxE 89bZzBMYeWYhSc1CklrAyLSKUSQzryw3MTPHVK84O6MyL7NCLzk/dxMjMJqW1f6ZuIPxy2X3 Q4wCHIxKPLw//i5OFWJNLCuuzD3EKMHBrCTCe/D5glQh3pTEyqrUovz4otKc1OJDjNIcLEri vF7hqQlCAumJJanZqakFqUUwWSYOTqkGRqbaO1OuvHgSdnYul/4aucDwdGFt23Ov6vpzOu9F Bu+7kptwcMqpokCmw9/3LGPdt8xE5rD3pukGvtKG7drnbss2T/jQqPU/7lZPr+MOP9kjYbbO xw8yf9QoeNCb+GXTlrTrIgEB1aq7DxlkmEQn+J/7n6aaqHQ0sr7rw6VpH6vN50+7xm60Roml OCPRUIu5qDgRAHgQXk+iAgAA X-CFilter-Loop: Reflected This patch introduces DAMOS_DEMOTE action, which is similar to DAMOS_PAGEOUT, but demote folios instead of swapping them out. Since there are some common routines with pageout, many functions have similar logics between pageout and demote. The execution sequence of DAMOS_PAGEOUT and DAMOS_DEMOTE look as follows. DAMOS_PAGEOUT action damo_pa_apply_scheme -> damon_pa_reclaim -> reclaim_pages -> reclaim_folio_list -> shrink_folio_list DAMOS_DEMOTE action damo_pa_apply_scheme -> damon_pa_reclaim -> demote_pages -> do_demote_folio_list -> __demote_folio_list -> demote_folio_list __demote_folio_list() is a minimized version of shrink_folio_list(), but it's minified only for demotion. Signed-off-by: Honggyu Kim --- include/linux/damon.h | 2 + mm/damon/paddr.c | 17 +++++--- mm/damon/sysfs-schemes.c | 1 + mm/internal.h | 1 + mm/vmscan.c | 84 ++++++++++++++++++++++++++++++++++++++++ 5 files changed, 99 insertions(+), 6 deletions(-) diff --git a/include/linux/damon.h b/include/linux/damon.h index e00ddf1ed39c..4c0a0fef09c5 100644 --- a/include/linux/damon.h +++ b/include/linux/damon.h @@ -106,6 +106,7 @@ struct damon_target { * @DAMOS_LRU_PRIO: Prioritize the region on its LRU lists. * @DAMOS_LRU_DEPRIO: Deprioritize the region on its LRU lists. * @DAMOS_STAT: Do nothing but count the stat. + * @DAMOS_DEMOTE: Do demotion for the current region. * @NR_DAMOS_ACTIONS: Total number of DAMOS actions * * The support of each action is up to running &struct damon_operations. @@ -123,6 +124,7 @@ enum damos_action { DAMOS_LRU_PRIO, DAMOS_LRU_DEPRIO, DAMOS_STAT, /* Do nothing but only record the stat */ + DAMOS_DEMOTE, NR_DAMOS_ACTIONS, }; diff --git a/mm/damon/paddr.c b/mm/damon/paddr.c index 081e2a325778..d3e3f077cd00 100644 --- a/mm/damon/paddr.c +++ b/mm/damon/paddr.c @@ -224,7 +224,7 @@ static bool damos_pa_filter_out(struct damos *scheme, struct folio *folio) return false; } -static unsigned long damon_pa_pageout(struct damon_region *r, struct damos *s) +static unsigned long damon_pa_reclaim(struct damon_region *r, struct damos *s, bool is_demote) { unsigned long addr, applied; LIST_HEAD(folio_list); @@ -242,14 +242,17 @@ static unsigned long damon_pa_pageout(struct damon_region *r, struct damos *s) folio_test_clear_young(folio); if (!folio_isolate_lru(folio)) goto put_folio; - if (folio_test_unevictable(folio)) + if (folio_test_unevictable(folio) && !is_demote) folio_putback_lru(folio); else list_add(&folio->lru, &folio_list); put_folio: folio_put(folio); } - applied = reclaim_pages(&folio_list); + if (is_demote) + applied = demote_pages(&folio_list); + else + applied = reclaim_pages(&folio_list); cond_resched(); return applied * PAGE_SIZE; } @@ -297,13 +300,15 @@ static unsigned long damon_pa_apply_scheme(struct damon_ctx *ctx, { switch (scheme->action) { case DAMOS_PAGEOUT: - return damon_pa_pageout(r, scheme); + return damon_pa_reclaim(r, scheme, false); case DAMOS_LRU_PRIO: return damon_pa_mark_accessed(r, scheme); case DAMOS_LRU_DEPRIO: return damon_pa_deactivate_pages(r, scheme); case DAMOS_STAT: break; + case DAMOS_DEMOTE: + return damon_pa_reclaim(r, scheme, true); default: /* DAMOS actions that not yet supported by 'paddr'. */ break; @@ -317,11 +322,11 @@ static int damon_pa_scheme_score(struct damon_ctx *context, { switch (scheme->action) { case DAMOS_PAGEOUT: + case DAMOS_LRU_DEPRIO: + case DAMOS_DEMOTE: return damon_cold_score(context, r, scheme); case DAMOS_LRU_PRIO: return damon_hot_score(context, r, scheme); - case DAMOS_LRU_DEPRIO: - return damon_cold_score(context, r, scheme); default: break; } diff --git a/mm/damon/sysfs-schemes.c b/mm/damon/sysfs-schemes.c index fe0fe2562000..ac7cd3f17b12 100644 --- a/mm/damon/sysfs-schemes.c +++ b/mm/damon/sysfs-schemes.c @@ -1187,6 +1187,7 @@ static const char * const damon_sysfs_damos_action_strs[] = { "lru_prio", "lru_deprio", "stat", + "demote", }; static struct damon_sysfs_scheme *damon_sysfs_scheme_alloc( diff --git a/mm/internal.h b/mm/internal.h index b61034bd50f5..2380397ec2f3 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -869,6 +869,7 @@ extern void set_pageblock_order(void); unsigned long reclaim_pages(struct list_head *folio_list); unsigned int reclaim_clean_pages_from_list(struct zone *zone, struct list_head *folio_list); +unsigned long demote_pages(struct list_head *folio_list); /* The ALLOC_WMARK bits are used as an index to zone->watermark */ #define ALLOC_WMARK_MIN WMARK_MIN #define ALLOC_WMARK_LOW WMARK_LOW diff --git a/mm/vmscan.c b/mm/vmscan.c index 7ca2396ccc3b..eaa3dd6b7562 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -998,6 +998,66 @@ static bool may_enter_fs(struct folio *folio, gfp_t gfp_mask) return !data_race(folio_swap_flags(folio) & SWP_FS_OPS); } +/* + * __demote_folio_list() returns the number of demoted pages + */ +static unsigned int __demote_folio_list(struct list_head *folio_list, + struct pglist_data *pgdat, struct scan_control *sc) +{ + LIST_HEAD(ret_folios); + LIST_HEAD(demote_folios); + unsigned int nr_demoted = 0; + + if (next_demotion_node(pgdat->node_id) == NUMA_NO_NODE) + return 0; + + cond_resched(); + + while (!list_empty(folio_list)) { + struct folio *folio; + enum folio_references references; + + cond_resched(); + + folio = lru_to_folio(folio_list); + list_del(&folio->lru); + + if (!folio_trylock(folio)) + goto keep; + + VM_BUG_ON_FOLIO(folio_test_active(folio), folio); + + references = folio_check_references(folio, sc); + if (references == FOLIOREF_KEEP) + goto keep_locked; + + /* Relocate its contents to another node. */ + list_add(&folio->lru, &demote_folios); + folio_unlock(folio); + continue; +keep_locked: + folio_unlock(folio); +keep: + list_add(&folio->lru, &ret_folios); + VM_BUG_ON_FOLIO(folio_test_lru(folio), folio); + } + /* 'folio_list' is always empty here */ + + /* Migrate folios selected for demotion */ + nr_demoted += demote_folio_list(&demote_folios, pgdat); + /* Folios that could not be demoted are still in @demote_folios */ + if (!list_empty(&demote_folios)) { + /* Folios which weren't demoted go back on @folio_list */ + list_splice_init(&demote_folios, folio_list); + } + + try_to_unmap_flush(); + + list_splice(&ret_folios, folio_list); + + return nr_demoted; +} + /* * shrink_folio_list() returns the number of reclaimed pages */ @@ -2107,6 +2167,25 @@ static unsigned int reclaim_folio_list(struct list_head *folio_list, return nr_reclaimed; } +static unsigned int do_demote_folio_list(struct list_head *folio_list, + struct pglist_data *pgdat) +{ + unsigned int nr_demoted; + struct folio *folio; + struct scan_control sc = { + .gfp_mask = GFP_KERNEL, + }; + + nr_demoted = __demote_folio_list(folio_list, pgdat, &sc); + while (!list_empty(folio_list)) { + folio = lru_to_folio(folio_list); + list_del(&folio->lru); + folio_putback_lru(folio); + } + + return nr_demoted; +} + static unsigned long reclaim_or_migrate_folios(struct list_head *folio_list, unsigned int (*handler)(struct list_head *, struct pglist_data *)) { @@ -2146,6 +2225,11 @@ unsigned long reclaim_pages(struct list_head *folio_list) return reclaim_or_migrate_folios(folio_list, reclaim_folio_list); } +unsigned long demote_pages(struct list_head *folio_list) +{ + return reclaim_or_migrate_folios(folio_list, do_demote_folio_list); +} + static unsigned long shrink_list(enum lru_list lru, unsigned long nr_to_scan, struct lruvec *lruvec, struct scan_control *sc) {