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]) by smtp.lore.kernel.org (Postfix) with ESMTP id E7C3FC54798 for ; Tue, 5 Mar 2024 07:54:11 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 7F9426B007B; Tue, 5 Mar 2024 02:54:11 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 7A8D66B0083; Tue, 5 Mar 2024 02:54:11 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 696FF6B007D; Tue, 5 Mar 2024 02:54:11 -0500 (EST) 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 55CCC6B0083 for ; Tue, 5 Mar 2024 02:54:11 -0500 (EST) Received: from smtpin03.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id 2E51B1A01DD for ; Tue, 5 Mar 2024 07:54:11 +0000 (UTC) X-FDA: 81862222302.03.69E46CF Received: from out-179.mta1.migadu.com (out-179.mta1.migadu.com [95.215.58.179]) by imf03.hostedemail.com (Postfix) with ESMTP id 5DBEA20004 for ; Tue, 5 Mar 2024 07:54:09 +0000 (UTC) Authentication-Results: imf03.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=pcO7Xmma; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf03.hostedemail.com: domain of chengming.zhou@linux.dev designates 95.215.58.179 as permitted sender) smtp.mailfrom=chengming.zhou@linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1709625249; 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:in-reply-to:references:references:dkim-signature; bh=GxATmqBlQcF/EJ5kBIVDHEOYeOEx3YPhEio6KYFOETw=; b=Iy92w8yW3wc6FtEoa0ufIcvGoMW2uMDl4IaPRT1UdMlH7qs/F7QpnHtqE0l3AnKy4aRd/9 MjeO5gl4rR5mGoXzfUISlC/v4oKn1zf1XYvdw9a2DRetE1iEkwBjuPt4RiBBdsbHCM7WSG lhIrPgcScc+aQIs9WRs6D+J6TkYyVuw= ARC-Authentication-Results: i=1; imf03.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=pcO7Xmma; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf03.hostedemail.com: domain of chengming.zhou@linux.dev designates 95.215.58.179 as permitted sender) smtp.mailfrom=chengming.zhou@linux.dev ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1709625249; a=rsa-sha256; cv=none; b=iWldEcdGyC2PiTaeD/ykqHY5ydwVw9f6ENvoX6cVyy5DMMecsqz/bx8G4+stsZoxzEbSP7 LDTcG5gGIjH+yq++EIJwkweSZArwAOb+QWU8KArgI4z0UZgQ0sdlDbmXkSesz/6Prguieh av+Uget4teRNm0ExHP+nan9p4F+IifU= 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=1709625245; 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: in-reply-to:in-reply-to:references:references; bh=GxATmqBlQcF/EJ5kBIVDHEOYeOEx3YPhEio6KYFOETw=; b=pcO7Xmma3GJNF/hFdo7RBa5GCJ8H183eLyC3T6gsdNlu++hf86a5nM9x5lQcXNXYgrJzVX hpV4BMBelKWyUVGGJaSp6Wwo+FBzoi+eiFPFfFALKb4R8miHOZVH0AYN1D6CDweLmjTK66 uJ81eKBGR0I1JUkt5cMX1eTNNsjIftE= From: Chengming Zhou To: akpm@linux-foundation.org Cc: hannes@cmpxchg.org, yosryahmed@google.com, nphamcs@gmail.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Chengming Zhou , kernel test robot Subject: [PATCH mm-unstable] mm/zswap: global lru and shrinker shared by all zswap_pools fix Date: Tue, 5 Mar 2024 07:53:45 +0000 Message-Id: <20240305075345.1493214-1-chengming.zhou@linux.dev> In-Reply-To: <20240210-zswap-global-lru-v3-1-200495333595@bytedance.com> References: <20240210-zswap-global-lru-v3-1-200495333595@bytedance.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-Rspamd-Queue-Id: 5DBEA20004 X-Rspam-User: X-Rspamd-Server: rspam04 X-Stat-Signature: 5mi6rjta9qzse1n38mix4nx1eumht5z5 X-HE-Tag: 1709625249-239473 X-HE-Meta: U2FsdGVkX1/YQ9knibdtkD2nt08vbQ+hKxDff/YaARzElj6HZxp3nlcG3BW6DTGWYN6+XHoME1V3c7126+f8hoOYxgPDEQQkOfLy/TqNd+35bj+2zaotsC9OZ676X8m4+bwKuDR2lQalPJaZmWLBYcq63JTfVk32fWUce+XOONjZWJQaY1xqyP3iY1vVlaktzyDM8ClRm6MMhOKTxWtYVkMxhYIrhYErD+sm9FctITWHDIXG2EKhAlwpzQrb/bTCxEyOOTGJb0oYYE8rLcWxmX5c1o+9jTv84oOpE52HAxBNWEzKx9lHcnU4UCc0VwnUc+7jCC/Vr5INjvrSQiKh1OEHpDrk8BFuHOEC6mf9xgGlDw+VQ+XHCCH6WNkmtY8NGZRbY5ztRcjagLYps9nlPYf9rU7DkElB6IgqvRWL20PDy+KWMDdAwXSuyuNkYDa+eXQP3z4CQaD/3uqbDd05Z+Ip8i1/JlC2Gm2veYgXt4GINQUkQCKSVWkFpahFCDPc1hbjY0psX2IwI9oh2VyScZM+xS7Gn/cNisARV28J+0BYecny+fUhqtuHky83W7gjT0ETMpYKEGxNq5gTOLeDfCN4Qf6ZPGlHr8DBemp2zrSrmzupnSwNrkIzfeiYcHAEuSO5JyWugtf1MNu96a48Oh7IRHLTwTCuhOvBshuJ8YxKcmo3BQxdfgzfyH1bk7eetiLJL3KFdxFHHgD/4HSwMpWsUBJ00FkxZu/NciPSFSRR7vj+LSDIbVfWVj5C+DzaHAvrwgvSLvB4tf3G3UMn8kStjDysqLauBYQlB653USKxJVTWz0+GWHCe5tjleAksKTmyhgFzikaOyE6uYw00BdceuZgnR895ystIHj//Fzb/D5+eNrU2sv4r/g40gNOH 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: The commit bf9b7df23cb3 ("mm/zswap: global lru and shrinker shared by all zswap_pools") introduced a new lock to protect zswap_next_shrink, instead of reusing zswap_pools_lock. But the problem is that it's initialized only when zswap enabled, which causes bug if zswap_memcg_offline_cleanup() called without zswap enabled. Fix it by using DEFINE_SPINLOCK() to statically initialize them and define them as multiple static variables to keep in consistent with the existing global variables in zswap. Fixes: bf9b7df23cb3 ("mm/zswap: global lru and shrinker shared by all zswap_pools") Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-lkp/202403051008.a8cf8a94-lkp@intel.com Signed-off-by: Chengming Zhou --- mm/zswap.c | 77 +++++++++++++++++++++++++++--------------------------- 1 file changed, 38 insertions(+), 39 deletions(-) diff --git a/mm/zswap.c b/mm/zswap.c index da90933c6d20..9a3237752082 100644 --- a/mm/zswap.c +++ b/mm/zswap.c @@ -180,15 +180,16 @@ struct zswap_pool { char tfm_name[CRYPTO_MAX_ALG_NAME]; }; -static struct { - struct list_lru list_lru; - atomic_t nr_stored; - struct shrinker *shrinker; - struct work_struct shrink_work; - struct mem_cgroup *next_shrink; - /* The lock protects next_shrink. */ - spinlock_t shrink_lock; -} zswap; +/* Global LRU lists shared by all zswap pools. */ +static struct list_lru zswap_list_lru; +/* counter of pages stored in all zswap pools. */ +static atomic_t zswap_nr_stored = ATOMIC_INIT(0); + +/* The lock protects zswap_next_shrink updates. */ +static DEFINE_SPINLOCK(zswap_shrink_lock); +static struct mem_cgroup *zswap_next_shrink; +static struct work_struct zswap_shrink_work; +static struct shrinker *zswap_shrinker; /* * struct zswap_entry @@ -798,10 +799,10 @@ void zswap_folio_swapin(struct folio *folio) void zswap_memcg_offline_cleanup(struct mem_cgroup *memcg) { /* lock out zswap shrinker walking memcg tree */ - spin_lock(&zswap.shrink_lock); - if (zswap.next_shrink == memcg) - zswap.next_shrink = mem_cgroup_iter(NULL, zswap.next_shrink, NULL); - spin_unlock(&zswap.shrink_lock); + spin_lock(&zswap_shrink_lock); + if (zswap_next_shrink == memcg) + zswap_next_shrink = mem_cgroup_iter(NULL, zswap_next_shrink, NULL); + spin_unlock(&zswap_shrink_lock); } /********************************* @@ -900,9 +901,9 @@ static void zswap_entry_free(struct zswap_entry *entry) if (!entry->length) atomic_dec(&zswap_same_filled_pages); else { - zswap_lru_del(&zswap.list_lru, entry); + zswap_lru_del(&zswap_list_lru, entry); zpool_free(zswap_find_zpool(entry), entry->handle); - atomic_dec(&zswap.nr_stored); + atomic_dec(&zswap_nr_stored); zswap_pool_put(entry->pool); } if (entry->objcg) { @@ -1274,7 +1275,7 @@ static unsigned long zswap_shrinker_scan(struct shrinker *shrinker, nr_protected = atomic_long_read(&lruvec->zswap_lruvec_state.nr_zswap_protected); - lru_size = list_lru_shrink_count(&zswap.list_lru, sc); + lru_size = list_lru_shrink_count(&zswap_list_lru, sc); /* * Abort if we are shrinking into the protected region. @@ -1291,7 +1292,7 @@ static unsigned long zswap_shrinker_scan(struct shrinker *shrinker, return SHRINK_STOP; } - shrink_ret = list_lru_shrink_walk(&zswap.list_lru, sc, &shrink_memcg_cb, + shrink_ret = list_lru_shrink_walk(&zswap_list_lru, sc, &shrink_memcg_cb, &encountered_page_in_swapcache); if (encountered_page_in_swapcache) @@ -1317,7 +1318,7 @@ static unsigned long zswap_shrinker_count(struct shrinker *shrinker, #else /* use pool stats instead of memcg stats */ nr_backing = zswap_pool_total_size >> PAGE_SHIFT; - nr_stored = atomic_read(&zswap.nr_stored); + nr_stored = atomic_read(&zswap_nr_stored); #endif if (!nr_stored) @@ -1325,7 +1326,7 @@ static unsigned long zswap_shrinker_count(struct shrinker *shrinker, nr_protected = atomic_long_read(&lruvec->zswap_lruvec_state.nr_zswap_protected); - nr_freeable = list_lru_shrink_count(&zswap.list_lru, sc); + nr_freeable = list_lru_shrink_count(&zswap_list_lru, sc); /* * Subtract the lru size by an estimate of the number of pages * that should be protected. @@ -1374,7 +1375,7 @@ static int shrink_memcg(struct mem_cgroup *memcg) for_each_node_state(nid, N_NORMAL_MEMORY) { unsigned long nr_to_walk = 1; - shrunk += list_lru_walk_one(&zswap.list_lru, nid, memcg, + shrunk += list_lru_walk_one(&zswap_list_lru, nid, memcg, &shrink_memcg_cb, NULL, &nr_to_walk); } return shrunk ? 0 : -EAGAIN; @@ -1387,9 +1388,9 @@ static void shrink_worker(struct work_struct *w) /* global reclaim will select cgroup in a round-robin fashion. */ do { - spin_lock(&zswap.shrink_lock); - zswap.next_shrink = mem_cgroup_iter(NULL, zswap.next_shrink, NULL); - memcg = zswap.next_shrink; + spin_lock(&zswap_shrink_lock); + zswap_next_shrink = mem_cgroup_iter(NULL, zswap_next_shrink, NULL); + memcg = zswap_next_shrink; /* * We need to retry if we have gone through a full round trip, or if we @@ -1403,7 +1404,7 @@ static void shrink_worker(struct work_struct *w) * memcg is not killed when we are reclaiming. */ if (!memcg) { - spin_unlock(&zswap.shrink_lock); + spin_unlock(&zswap_shrink_lock); if (++failures == MAX_RECLAIM_RETRIES) break; @@ -1413,15 +1414,15 @@ static void shrink_worker(struct work_struct *w) if (!mem_cgroup_tryget_online(memcg)) { /* drop the reference from mem_cgroup_iter() */ mem_cgroup_iter_break(NULL, memcg); - zswap.next_shrink = NULL; - spin_unlock(&zswap.shrink_lock); + zswap_next_shrink = NULL; + spin_unlock(&zswap_shrink_lock); if (++failures == MAX_RECLAIM_RETRIES) break; goto resched; } - spin_unlock(&zswap.shrink_lock); + spin_unlock(&zswap_shrink_lock); ret = shrink_memcg(memcg); /* drop the extra reference */ @@ -1542,7 +1543,7 @@ bool zswap_store(struct folio *folio) if (objcg) { memcg = get_mem_cgroup_from_objcg(objcg); - if (memcg_list_lru_alloc(memcg, &zswap.list_lru, GFP_KERNEL)) { + if (memcg_list_lru_alloc(memcg, &zswap_list_lru, GFP_KERNEL)) { mem_cgroup_put(memcg); goto put_pool; } @@ -1573,8 +1574,8 @@ bool zswap_store(struct folio *folio) } if (entry->length) { INIT_LIST_HEAD(&entry->lru); - zswap_lru_add(&zswap.list_lru, entry); - atomic_inc(&zswap.nr_stored); + zswap_lru_add(&zswap_list_lru, entry); + atomic_inc(&zswap_nr_stored); } spin_unlock(&tree->lock); @@ -1606,7 +1607,7 @@ bool zswap_store(struct folio *folio) return false; shrink: - queue_work(shrink_wq, &zswap.shrink_work); + queue_work(shrink_wq, &zswap_shrink_work); goto reject; } @@ -1773,16 +1774,14 @@ static int zswap_setup(void) if (!shrink_wq) goto shrink_wq_fail; - zswap.shrinker = zswap_alloc_shrinker(); - if (!zswap.shrinker) + zswap_shrinker = zswap_alloc_shrinker(); + if (!zswap_shrinker) goto shrinker_fail; - if (list_lru_init_memcg(&zswap.list_lru, zswap.shrinker)) + if (list_lru_init_memcg(&zswap_list_lru, zswap_shrinker)) goto lru_fail; - shrinker_register(zswap.shrinker); + shrinker_register(zswap_shrinker); - INIT_WORK(&zswap.shrink_work, shrink_worker); - atomic_set(&zswap.nr_stored, 0); - spin_lock_init(&zswap.shrink_lock); + INIT_WORK(&zswap_shrink_work, shrink_worker); pool = __zswap_pool_create_fallback(); if (pool) { @@ -1801,7 +1800,7 @@ static int zswap_setup(void) return 0; lru_fail: - shrinker_free(zswap.shrinker); + shrinker_free(zswap_shrinker); shrinker_fail: destroy_workqueue(shrink_wq); shrink_wq_fail: -- 2.40.1