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h=from:from:reply-to: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=dIw1VlS+yjt3d7a9qpfJxscOym6tjt6rE1MC5A8rBPI=; b=tVb8H+92nFnhsWRMMDYQ35nU9pRXfcuVXHbPwtPBu7GgiOBE9VSfVpqIWxxmn19LlAknKo vqKdiNXZxvwOyUBw== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 2073013BE0; Mon, 23 Aug 2021 14:58:41 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id gGjPBqG3I2EFQQAAMHmgww (envelope-from ); Mon, 23 Aug 2021 14:58:41 +0000 From: Vlastimil Babka To: Andrew Morton , Christoph Lameter , David Rientjes , Pekka Enberg , Joonsoo Kim Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Mike Galbraith , Sebastian Andrzej Siewior , Thomas Gleixner , Mel Gorman , Jesper Dangaard Brouer , Jann Horn , Vlastimil Babka Subject: [PATCH v5 20/35] mm, slub: make locking in deactivate_slab() irq-safe Date: Mon, 23 Aug 2021 16:58:11 +0200 Message-Id: <20210823145826.3857-21-vbabka@suse.cz> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210823145826.3857-1-vbabka@suse.cz> References: <20210823145826.3857-1-vbabka@suse.cz> MIME-Version: 1.0 Authentication-Results: imf16.hostedemail.com; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=1r+qEomo; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=tVb8H+92; dmarc=none; spf=pass (imf16.hostedemail.com: domain of vbabka@suse.cz designates 195.135.220.29 as permitted sender) smtp.mailfrom=vbabka@suse.cz X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 373E1F000099 X-Stat-Signature: fac1h4k7714ti8b9p4o8qzt8f6bjqehg X-HE-Tag: 1629730722-70391 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: dectivate_slab() now no longer touches the kmem_cache_cpu structure, so it will be possible to call it with irqs enabled. Just convert the spin_lock calls to their irq saving/restoring variants to make it irq-safe. Note we now have to use cmpxchg_double_slab() for irq-safe slab_lock(), because in some situations we don't take the list_lock, which would disable irqs. Signed-off-by: Vlastimil Babka --- mm/slub.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/mm/slub.c b/mm/slub.c index ef36c94f27e2..00a96e9030e5 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -2209,6 +2209,7 @@ static void deactivate_slab(struct kmem_cache *s, struct page *page, enum slab_modes l = M_NONE, m = M_NONE; void *nextfree, *freelist_iter, *freelist_tail; int tail = DEACTIVATE_TO_HEAD; + unsigned long flags = 0; struct page new; struct page old; @@ -2284,7 +2285,7 @@ static void deactivate_slab(struct kmem_cache *s, struct page *page, * that acquire_slab() will see a slab page that * is frozen */ - spin_lock(&n->list_lock); + spin_lock_irqsave(&n->list_lock, flags); } } else { m = M_FULL; @@ -2295,7 +2296,7 @@ static void deactivate_slab(struct kmem_cache *s, struct page *page, * slabs from diagnostic functions will not see * any frozen slabs. */ - spin_lock(&n->list_lock); + spin_lock_irqsave(&n->list_lock, flags); } } @@ -2312,14 +2313,14 @@ static void deactivate_slab(struct kmem_cache *s, struct page *page, } l = m; - if (!__cmpxchg_double_slab(s, page, + if (!cmpxchg_double_slab(s, page, old.freelist, old.counters, new.freelist, new.counters, "unfreezing slab")) goto redo; if (lock) - spin_unlock(&n->list_lock); + spin_unlock_irqrestore(&n->list_lock, flags); if (m == M_PARTIAL) stat(s, tail);