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,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 0581BC2B9F7 for ; Mon, 24 May 2021 23:42:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DB4C96140F for ; Mon, 24 May 2021 23:42:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230429AbhEXXnu (ORCPT ); Mon, 24 May 2021 19:43:50 -0400 Received: from mx2.suse.de ([195.135.220.15]:50880 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229945AbhEXXmW (ORCPT ); Mon, 24 May 2021 19:42:22 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1621899648; 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=0tu41fI/tehEDdtk24Fc6V86f4NZ4fbmTVRxT+6xDtI=; b=Q1Skr70Skr7DkCUY/22aNjYfRK5j6dEk/M2CeFxGX/GcyUZUfYfO9SbmIeuQfsqXYx3Yvi Pr6mVr8Y6yRZBbT9aCLvCZj3h5M1ASQ7kM4t3823AfQCIZFjGz9eecjS3IrWfNcRifgmkm rYg+U1i04g/9svGprw6LzAJBcJGqZrY= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1621899648; 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=0tu41fI/tehEDdtk24Fc6V86f4NZ4fbmTVRxT+6xDtI=; b=gehOBtx2kTGbnW2lNeAX/zy5asReW9dnmEwJj9Ip4kKlrR9IwB1Cj7KZOt1x64G3Vn1RGI Bbve3XL4DpJRIXBw== Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 9D871AF38; Mon, 24 May 2021 23:40:48 +0000 (UTC) From: Vlastimil Babka To: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Christoph Lameter , David Rientjes , Pekka Enberg , Joonsoo Kim Cc: Sebastian Andrzej Siewior , Thomas Gleixner , Mel Gorman , Jesper Dangaard Brouer , Peter Zijlstra , Jann Horn , Vlastimil Babka Subject: [RFC 16/26] mm, slub: move reset of c->page and freelist out of deactivate_slab() Date: Tue, 25 May 2021 01:39:36 +0200 Message-Id: <20210524233946.20352-17-vbabka@suse.cz> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210524233946.20352-1-vbabka@suse.cz> References: <20210524233946.20352-1-vbabka@suse.cz> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org deactivate_slab() removes the cpu slab by merging the cpu freelist with slab's freelist and putting the slab on the proper node's list. It also sets the respective kmem_cache_cpu pointers to NULL. By extracting the kmem_cache_cpu operations from the function, we can make it not dependent on disabled irqs. Also if we return a single free pointer from ___slab_alloc, we no longer have to load the slab page before deactivation or care if somebody preempted us and loaded a different slab page to our kmem_cache_cpu in the process. Signed-off-by: Vlastimil Babka --- mm/slub.c | 31 ++++++++++++++++++------------- 1 file changed, 18 insertions(+), 13 deletions(-) diff --git a/mm/slub.c b/mm/slub.c index bc7bee5d4bf2..cf855cd09802 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -2163,10 +2163,13 @@ static void init_kmem_cache_cpus(struct kmem_cache *s) } /* - * Remove the cpu slab + * Finishes removing the cpu slab. Merges cpu's freelist with page's freelist, + * unfreezes the slabs and puts it on the proper list. + * Assumes the slab has been already safely taken away from kmem_cache_cpu + * by the caller. */ static void deactivate_slab(struct kmem_cache *s, struct page *page, - void *freelist, struct kmem_cache_cpu *c) + void *freelist) { enum slab_modes { M_NONE, M_PARTIAL, M_FULL, M_FREE }; struct kmem_cache_node *n = get_node(s, page_to_nid(page)); @@ -2295,9 +2298,6 @@ static void deactivate_slab(struct kmem_cache *s, struct page *page, discard_slab(s, page); stat(s, FREE_SLAB); } - - c->page = NULL; - c->freelist = NULL; } /* @@ -2429,10 +2429,16 @@ static void put_cpu_partial(struct kmem_cache *s, struct page *page, int drain) static inline void flush_slab(struct kmem_cache *s, struct kmem_cache_cpu *c) { - stat(s, CPUSLAB_FLUSH); - deactivate_slab(s, c->page, c->freelist, c); + void *freelist = c->freelist; + struct page *page = c->page; + c->page = NULL; + c->freelist = NULL; c->tid = next_tid(c->tid); + + deactivate_slab(s, page, freelist); + + stat(s, CPUSLAB_FLUSH); } /* @@ -2712,7 +2718,10 @@ static void *___slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node, local_irq_restore(flags); goto reread_page; } - deactivate_slab(s, page, c->freelist, c); + freelist = c->freelist; + c->page = NULL; + c->freelist = NULL; + deactivate_slab(s, page, freelist); local_irq_restore(flags); new_slab: @@ -2792,11 +2801,7 @@ static void *___slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node, return_single: local_irq_save(flags); - if (unlikely(c->page)) - flush_slab(s, c); - c->page = page; - - deactivate_slab(s, page, get_freepointer(s, freelist), c); + deactivate_slab(s, page, get_freepointer(s, freelist)); local_irq_restore(flags); return freelist; } -- 2.31.1