From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id DD4BEC43458 for ; Fri, 10 Jul 2026 11:12:51 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id C9D176B0095; Fri, 10 Jul 2026 07:12:50 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C4E836B009D; Fri, 10 Jul 2026 07:12:50 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B66406B009E; Fri, 10 Jul 2026 07:12:50 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 8D9336B0095 for ; Fri, 10 Jul 2026 07:12:50 -0400 (EDT) Received: from smtpin05.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 17D1740426 for ; Fri, 10 Jul 2026 11:12:50 +0000 (UTC) X-FDA: 84972604500.05.62E0CD9 Received: from out-181.mta1.migadu.com (out-181.mta1.migadu.com [95.215.58.181]) by imf28.hostedemail.com (Postfix) with ESMTP id 53098C0004 for ; Fri, 10 Jul 2026 11:12:48 +0000 (UTC) Authentication-Results: imf28.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=IFqLqY3D; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf28.hostedemail.com: domain of ridong.chen@linux.dev designates 95.215.58.181 as permitted sender) smtp.mailfrom=ridong.chen@linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1783681968; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:references:dkim-signature; bh=ngy3pMTw2oJe0xcoHveOCKAvtR5RPrFr2htiJZs9bhY=; b=srXHXnMB/5OkBZkpBZwc20eo3wQ6/CFHLe76EFZCzgsYurhslOF40Afmnon/1MHAbomfqj vZENOWatlCRx0HetBfJrLGmaCElwsy5h6J86HxPq7PAlWKZB+Y6Kfypcd6l8oVhIoYLCK1 gbRgADgYjwg+CIdPQwEN4T+K3Alo/Cc= ARC-Authentication-Results: i=1; imf28.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=IFqLqY3D; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf28.hostedemail.com: domain of ridong.chen@linux.dev designates 95.215.58.181 as permitted sender) smtp.mailfrom=ridong.chen@linux.dev ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1783681968; b=vc9QGLBARxvI9GGUmNfGFrXalc5H+YiMppJ16bEcrnAMSsll9X4jfe4Lni821eX2Eo5XXg btgumEmNvYNoTdFpPs/YFMN3Uk31eN5czhS7d8RhaGm0xeKcMi2Sf2SCiFQ+1V02gZl4+0 YEjBZu2Kkg86vN346Gq9HsuMhJivMCc= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1783681966; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=ngy3pMTw2oJe0xcoHveOCKAvtR5RPrFr2htiJZs9bhY=; b=IFqLqY3DAom4XvqaOjOErkF9/erqvA8chQ+Lvm+KxY9AN68SP4P+GyN8fmmYCaSu1887qi KZpk284BSdJmi+2Wm7GfxTubHbzT+HC4h6mpzd6uxoaNVIVToJSbX/IhiC0GLuaRGx3gPf wuONTmcM/XJf5DAxbyn0aAfYDwWyLFU= From: Ridong To: Johannes Weiner , Michal Hocko , Roman Gushchin , Shakeel Butt , Andrew Morton , Chris Li , Kairui Song Cc: Muchun Song , Kemeng Shi , Nhat Pham , Baoquan He , Barry Song , Youngjun Park , cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, ridong.chen@linux.dev, Ridong Chen Subject: [PATCH -next] memcg: move mem_cgroup_swappiness to memcontrol.h Date: Fri, 10 Jul 2026 19:12:24 +0800 Message-Id: <20260710111224.2355668-1-ridong.chen@linux.dev> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 53098C0004 X-Stat-Signature: mtsw8di6x37gsydwxnzf3d8598wqinfu X-Rspam-User: X-HE-Tag: 1783681968-436776 X-HE-Meta: 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 c6VehKzd pe49THSKzanHDEHYAvoIfBXFC4NW0QiM6tEDkDyn7gbmn8LAOIvsbcVwnndHaagglSSD0ErX2lqvZRo6j43eMB2FzaOvHyHgsQQzo/nI909Lcw8Lh39Uw4l9VZQTCQ0a2KNRonOlPwNQymUGV7hkFIpUEnOqyfU9duKwPY/Zz/l8q/FmPXkNvfFIGX2ldGScXeQCrcQ9b5KLm6lNi/1ApZLEZg8ES6b0udm0b1U0I7UOp5FSxxtDwcyQaz/0Y5XKHGqIOMiP6s8ztbW4= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: From: Ridong Chen The per-memcg swappiness knob is v1-only; v2 always uses global vm_swappiness and ignores the per-cgroup field. Guard memcg->swappiness with CONFIG_MEMCG_V1, and move the helper to memcontrol.h where it belongs. No functional change for v1; v2-only kernels drop the unused field. Signed-off-by: Ridong Chen --- include/linux/memcontrol.h | 25 +++++++++++++++++++++++-- include/linux/swap.h | 19 ------------------- mm/memcontrol.c | 3 +-- 3 files changed, 24 insertions(+), 23 deletions(-) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index e1f46a0016fc..f59614956f96 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -239,8 +239,6 @@ struct mem_cgroup { */ bool oom_group; - int swappiness; - /* memory.events and memory.events.local */ struct cgroup_file events_file; struct cgroup_file events_local_file; @@ -318,6 +316,9 @@ struct mem_cgroup { /* List of events which userspace want to receive */ struct list_head event_list; spinlock_t event_list_lock; + + int swappiness; + #endif /* CONFIG_MEMCG_V1 */ struct mem_cgroup_per_node *nodeinfo[]; @@ -365,6 +366,9 @@ enum objext_flags { #define OBJEXTS_FLAGS_MASK (__NR_OBJEXTS_FLAGS - 1) +/* Defined in mm/vmscan.c; used by mem_cgroup_swappiness(). */ +extern int vm_swappiness; + #ifdef CONFIG_MEMCG /* * After the initialization objcg->memcg is always pointing at @@ -1440,6 +1444,23 @@ static inline void mem_cgroup_flush_workqueue(void) { } static inline int mem_cgroup_init(void) { return 0; } #endif /* CONFIG_MEMCG */ +static inline int mem_cgroup_swappiness(struct mem_cgroup *memcg) +{ +#ifdef CONFIG_MEMCG_V1 + /* Cgroup2 doesn't have per-cgroup swappiness */ + if (cgroup_subsys_on_dfl(memory_cgrp_subsys)) + return READ_ONCE(vm_swappiness); + + /* root ? */ + if (mem_cgroup_disabled() || mem_cgroup_is_root(memcg)) + return READ_ONCE(vm_swappiness); + + return READ_ONCE(memcg->swappiness); +#else + return READ_ONCE(vm_swappiness); +#endif +} + /* * Extended information for slab objects stored as an array in page->memcg_data * if MEMCG_DATA_OBJEXTS is set. diff --git a/include/linux/swap.h b/include/linux/swap.h index 3f31b6a56788..f27e73f29195 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -366,7 +366,6 @@ extern unsigned long mem_cgroup_shrink_node(struct mem_cgroup *mem, pg_data_t *pgdat, unsigned long *nr_scanned); extern unsigned long shrink_all_memory(unsigned long nr_pages); -extern int vm_swappiness; long remove_mapping(struct address_space *mapping, struct folio *folio); #if defined(CONFIG_SYSFS) && defined(CONFIG_NUMA) @@ -530,25 +529,7 @@ static inline int add_swap_extent(struct swap_info_struct *sis, } #endif /* CONFIG_SWAP */ #ifdef CONFIG_MEMCG -static inline int mem_cgroup_swappiness(struct mem_cgroup *memcg) -{ - /* Cgroup2 doesn't have per-cgroup swappiness */ - if (cgroup_subsys_on_dfl(memory_cgrp_subsys)) - return READ_ONCE(vm_swappiness); - - /* root ? */ - if (mem_cgroup_disabled() || mem_cgroup_is_root(memcg)) - return READ_ONCE(vm_swappiness); - - return READ_ONCE(memcg->swappiness); -} - void lru_reparent_memcg(struct mem_cgroup *memcg, struct mem_cgroup *parent, int nid); -#else -static inline int mem_cgroup_swappiness(struct mem_cgroup *mem) -{ - return READ_ONCE(vm_swappiness); -} #endif #if defined(CONFIG_SWAP) && defined(CONFIG_MEMCG) && defined(CONFIG_BLK_CGROUP) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 938f190a98fe..2d659b76cd77 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -4174,11 +4174,10 @@ mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) #endif page_counter_set_high(&memcg->swap, PAGE_COUNTER_MAX); if (parent) { - WRITE_ONCE(memcg->swappiness, mem_cgroup_swappiness(parent)); - page_counter_init(&memcg->memory, &parent->memory, memcg_on_dfl); page_counter_init(&memcg->swap, &parent->swap, false); #ifdef CONFIG_MEMCG_V1 + WRITE_ONCE(memcg->swappiness, mem_cgroup_swappiness(parent)); memcg->memory.track_failcnt = !memcg_on_dfl; WRITE_ONCE(memcg->oom_kill_disable, READ_ONCE(parent->oom_kill_disable)); page_counter_init(&memcg->kmem, &parent->kmem, false); -- 2.34.1