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 X-Spam-Level: X-Spam-Status: No, score=-17.0 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3E329C433DB for ; Tue, 16 Feb 2021 17:04:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 15C5164DEC for ; Tue, 16 Feb 2021 17:04:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230391AbhBPREm (ORCPT ); Tue, 16 Feb 2021 12:04:42 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56656 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230001AbhBPREi (ORCPT ); Tue, 16 Feb 2021 12:04:38 -0500 Received: from mail-pg1-x536.google.com (mail-pg1-x536.google.com [IPv6:2607:f8b0:4864:20::536]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1305FC06174A; Tue, 16 Feb 2021 09:03:58 -0800 (PST) Received: by mail-pg1-x536.google.com with SMTP id p21so963822pgl.12; Tue, 16 Feb 2021 09:03:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=DfwDzVk1NHB5T9HsjyNqMcwEKAYtkzgp0UAGcMX/HB8=; b=htEorIJ+dmdnPpGtj13u9TsG6Q+w5Ev61teJTqxY2tyiVQO37h7AKhrxgdoYqBwrI4 J5JXCLJOII5fcMCWbDF/FG9CF3Xodb7T3d4+jzYHOoKQ06gDHgIM/wmK/bdCalH/O3Kn 6vqppxjqTTllh+RS4X+NKy5kIcTUnjiGazOkpTMh1DAx323RC6wYSMURn6wNyN+inqeQ LTQCrayW73nESN71nCh45bqFss2G1e1YfUdw1gvmj2YhGZy8ydqP1uwZP2iUEv/R6qvy R5tgTG4l4/JkXh4GOuYW2S6eZvOs+WmeTRfQmiqSD8LZpKNZ3ZOW6P0IV0OnnH8zxmAl R5Ig== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id :in-reply-to:references:mime-version:content-transfer-encoding; bh=DfwDzVk1NHB5T9HsjyNqMcwEKAYtkzgp0UAGcMX/HB8=; b=ADjpRy+NQW2rLfr1XgiJIFKCaauAxi83fbR3Zx8Yp0d2rUOJJ1OmpMbl/ka32acM82 UwQWEheW+h4fcXfWMzwwYGCNuclDV8in6w2PVKWCEDrg3Ik3+wfk/EH+iG4+QDZxKcaS O2JqufBvsWPDakjPurVruxCGZHjtKknQwXHPCoUrIjUwU1hjZdVZVA2DbP75DO6tY97H 7AtcP255wZJ0qvs2JTtmfW0ckMzE5yfuvHD2D1E87kEoV0MyGFgNcYJR1/TqyAhJsgtv Sb9uWc7UrP1gWVLewSs8QXASms+I7mXE7P6yNYu87DgRljp16cLJezuKxLMWE3j+DB+C Ef7g== X-Gm-Message-State: AOAM533qhAnJqNNTRFshDEZhYTcxulA1VprEVFNJFS32lHWyBmkZEwnx gK/yIPIWudHug5RMhj897Ew= X-Google-Smtp-Source: ABdhPJxPi89JXusezEuR2+j63Tw5YX1JwuFnLkLpfGiQLYi3zEz/6/51oQ/ZtclHZTMYeYxxgvTlvQ== X-Received: by 2002:a65:4942:: with SMTP id q2mr16931626pgs.34.1613495037636; Tue, 16 Feb 2021 09:03:57 -0800 (PST) Received: from bbox-1.mtv.corp.google.com ([2620:15c:211:201:fc2a:a664:489d:d48f]) by smtp.gmail.com with ESMTPSA id 143sm21876424pfw.3.2021.02.16.09.03.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 16 Feb 2021 09:03:56 -0800 (PST) Sender: Minchan Kim From: Minchan Kim To: Andrew Morton Cc: linux-mm , LKML , cgoldswo@codeaurora.org, linux-fsdevel@vger.kernel.org, willy@infradead.org, mhocko@suse.com, david@redhat.com, vbabka@suse.cz, viro@zeniv.linux.org.uk, joaodias@google.com, Minchan Kim Subject: [RFC 2/2] mm: fs: Invalidate BH LRU during page migration Date: Tue, 16 Feb 2021 09:03:48 -0800 Message-Id: <20210216170348.1513483-2-minchan@kernel.org> X-Mailer: git-send-email 2.30.0.478.g8a0d178c01-goog In-Reply-To: <20210216170348.1513483-1-minchan@kernel.org> References: <20210216170348.1513483-1-minchan@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Pages containing buffer_heads that are in one of the per-CPU buffer_head LRU caches will be pinned and thus cannot be migrated. This can prevent CMA allocations from succeeding, which are often used on platforms with co-processors (such as a DSP) that can only use physically contiguous memory. It can also prevent memory hot-unplugging from succeeding, which involves migrating at least MIN_MEMORY_BLOCK_SIZE bytes of memory, which ranges from 8 MiB to 1 GiB based on the architecture in use. Correspondingly, invalidate the BH LRU caches before a migration starts and stop any buffer_head from being cached in the LRU caches, until migration has finished. Signed-off-by: Chris Goldsworthy Signed-off-by: Minchan Kim --- fs/buffer.c | 13 +++++++++++-- include/linux/buffer_head.h | 2 ++ mm/swap.c | 5 ++++- 3 files changed, 17 insertions(+), 3 deletions(-) diff --git a/fs/buffer.c b/fs/buffer.c index 96c7604f69b3..de62e75d0ed0 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -45,6 +45,7 @@ #include #include #include +#include #include #include #include @@ -1301,6 +1302,14 @@ static void bh_lru_install(struct buffer_head *bh) int i; check_irqs_on(); + /* + * buffer_head in bh_lru could increase refcount of the page + * until it will be invalidated. It causes page migraion failure. + * Skip putting upcoming bh into bh_lru until migration is done. + */ + if (migrate_pending()) + return; + bh_lru_lock(); b = this_cpu_ptr(&bh_lrus); @@ -1446,7 +1455,7 @@ EXPORT_SYMBOL(__bread_gfp); * This doesn't race because it runs in each cpu either in irq * or with preempt disabled. */ -static void invalidate_bh_lru(void *arg) +void invalidate_bh_lru(void *arg) { struct bh_lru *b = &get_cpu_var(bh_lrus); int i; @@ -1458,7 +1467,7 @@ static void invalidate_bh_lru(void *arg) put_cpu_var(bh_lrus); } -static bool has_bh_in_lru(int cpu, void *dummy) +bool has_bh_in_lru(int cpu, void *dummy) { struct bh_lru *b = per_cpu_ptr(&bh_lrus, cpu); int i; diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h index 6b47f94378c5..3d98bdabaac9 100644 --- a/include/linux/buffer_head.h +++ b/include/linux/buffer_head.h @@ -194,6 +194,8 @@ void __breadahead_gfp(struct block_device *, sector_t block, unsigned int size, struct buffer_head *__bread_gfp(struct block_device *, sector_t block, unsigned size, gfp_t gfp); void invalidate_bh_lrus(void); +void invalidate_bh_lru(void *); +bool has_bh_in_lru(int cpu, void *dummy); struct buffer_head *alloc_buffer_head(gfp_t gfp_flags); void free_buffer_head(struct buffer_head * bh); void unlock_buffer(struct buffer_head *bh); diff --git a/mm/swap.c b/mm/swap.c index e42c4b4bf2b3..14faf558347b 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -37,6 +37,7 @@ #include #include #include +#include #include "internal.h" @@ -641,6 +642,7 @@ void lru_add_drain_cpu(int cpu) pagevec_lru_move_fn(pvec, lru_lazyfree_fn); activate_page_drain(cpu); + invalidate_bh_lru(NULL); } /** @@ -827,7 +829,8 @@ void lru_add_drain_all(void) pagevec_count(&per_cpu(lru_pvecs.lru_deactivate_file, cpu)) || pagevec_count(&per_cpu(lru_pvecs.lru_deactivate, cpu)) || pagevec_count(&per_cpu(lru_pvecs.lru_lazyfree, cpu)) || - need_activate_page_drain(cpu)) { + need_activate_page_drain(cpu) || + has_bh_in_lru(cpu, NULL)) { INIT_WORK(work, lru_add_drain_per_cpu); queue_work_on(cpu, mm_percpu_wq, work); __cpumask_set_cpu(cpu, &has_work); -- 2.30.0.478.g8a0d178c01-goog