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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham 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 9A4DAC4338F for ; Thu, 29 Jul 2021 13:23:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7F1C260184 for ; Thu, 29 Jul 2021 13:23:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237792AbhG2NXF (ORCPT ); Thu, 29 Jul 2021 09:23:05 -0400 Received: from smtp-out1.suse.de ([195.135.220.28]:38376 "EHLO smtp-out1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237512AbhG2NVr (ORCPT ); Thu, 29 Jul 2021 09:21:47 -0400 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 smtp-out1.suse.de (Postfix) with ESMTPS id 5D61B223CA; Thu, 29 Jul 2021 13:21:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1627564904; 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=UiCxRMMHMOS5L/ydhMEkZsbsrTOn4byCcROCCC2JXf4=; b=PqH1P7qLLkcXKDgXD6IE8BG16RZe41LGnaZXMz9YqjhUYdqHjc+cbQ3PT14w3bmOJ8C+DV 4uEFcVPFt4SKyvXaAOT5GPrP/sTXoRd9a+rYBFc0wzV5835nhCJDGz+yD13wBq8YXA+659 h2uf202DQq4LzHjNpIWtqA8lMuJicNQ= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1627564904; 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=UiCxRMMHMOS5L/ydhMEkZsbsrTOn4byCcROCCC2JXf4=; b=xEo5d3saBi/iGsw59tp8K87J57o+ylSeGBiXGkgb1x6d35m3p3gskxiUoQKHB1E9kmW1qG W39TPxCCe4ULtOCg== 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 2FCAA13AF4; Thu, 29 Jul 2021 13:21:44 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id uArTCmirAmF9AwAAMHmgww (envelope-from ); Thu, 29 Jul 2021 13:21:44 +0000 From: Vlastimil Babka To: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Christoph Lameter , David Rientjes , Pekka Enberg , Joonsoo Kim Cc: Mike Galbraith , Sebastian Andrzej Siewior , Thomas Gleixner , Mel Gorman , Jesper Dangaard Brouer , Jann Horn , Vlastimil Babka Subject: [PATCH v3 21/35] mm, slub: call deactivate_slab() without disabling irqs Date: Thu, 29 Jul 2021 15:21:18 +0200 Message-Id: <20210729132132.19691-22-vbabka@suse.cz> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210729132132.19691-1-vbabka@suse.cz> References: <20210729132132.19691-1-vbabka@suse.cz> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The function is now safe to be called with irqs enabled, so move the calls outside of irq disabled sections. When called from ___slab_alloc() -> flush_slab() we have irqs disabled, so to reenable them before deactivate_slab() we need to open-code flush_slab() in ___slab_alloc() and reenable irqs after modifying the kmem_cache_cpu fields. But that means a IRQ handler meanwhile might have assigned a new page to kmem_cache_cpu.page so we have to retry the whole check. The remaining callers of flush_slab() are the IPI handler which has disabled irqs anyway, and slub_cpu_dead() which will be dealt with in the following patch. Signed-off-by: Vlastimil Babka --- mm/slub.c | 24 +++++++++++++++++++----- 1 file changed, 19 insertions(+), 5 deletions(-) diff --git a/mm/slub.c b/mm/slub.c index 3d5a2f9371f8..1fdbc2ea8f67 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -2749,8 +2749,8 @@ static void *___slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node, freelist = c->freelist; c->page = NULL; c->freelist = NULL; - deactivate_slab(s, page, freelist); local_irq_restore(flags); + deactivate_slab(s, page, freelist); new_slab: @@ -2818,18 +2818,32 @@ static void *___slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node, */ goto return_single; +retry_load_page: + local_irq_save(flags); - if (unlikely(c->page)) - flush_slab(s, c); + if (unlikely(c->page)) { + void *flush_freelist = c->freelist; + struct page *flush_page = c->page; + + c->page = NULL; + c->freelist = NULL; + c->tid = next_tid(c->tid); + + local_irq_restore(flags); + + deactivate_slab(s, flush_page, flush_freelist); + + stat(s, CPUSLAB_FLUSH); + + goto retry_load_page; + } c->page = page; goto load_freelist; return_single: - local_irq_save(flags); deactivate_slab(s, page, get_freepointer(s, freelist)); - local_irq_restore(flags); return freelist; } -- 2.32.0