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 261CEC47085 for ; Mon, 24 May 2021 23:41:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0DD2B61421 for ; Mon, 24 May 2021 23:41:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230141AbhEXXmi (ORCPT ); Mon, 24 May 2021 19:42:38 -0400 Received: from mx2.suse.de ([195.135.220.15]:50688 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229875AbhEXXmU (ORCPT ); Mon, 24 May 2021 19:42:20 -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=1xmWeJ1b7AZlmflgkuweNV6NpHrLePBdboBsTBPbV/k=; b=JoaTF4rqBbwWtdHjrYUyCM/QqY0hcx8rqKdEwXsbGgayd9D7nrxrKjRRG96f1rr0pxkojB Q4Wq26PiCK1wcYmstYjpoDfT5IXgmDdqeCpHih3/V1+qCbGY6PockH5rxi7413yGns9vVO ZiBbgyoQxkBY5FQs/AGCcri2u4csPV4= 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=1xmWeJ1b7AZlmflgkuweNV6NpHrLePBdboBsTBPbV/k=; b=E7m4pF7yX975qQIzoPzuGk7jsqfXsunkwKDsF+v818VG1L4hZR5aSd1yRJVN9IMmKuc/cL KfzO/8ZKmHl/pJDQ== Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 1BAFFAF21; 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 08/26] mm, slub: restructure new page checks in ___slab_alloc() Date: Tue, 25 May 2021 01:39:28 +0200 Message-Id: <20210524233946.20352-9-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 When we allocate slab object from a newly acquired page (from node's partial list or page allocator), we usually also retain the page as a new percpu slab. There are two exceptions - when pfmemalloc status of the page doesn't match our gfp flags, or when the cache has debugging enabled. The current code for these decisions is not easy to follow, so restructure it and add comments. No functional change. Signed-off-by: Vlastimil Babka --- mm/slub.c | 28 ++++++++++++++++++++++------ 1 file changed, 22 insertions(+), 6 deletions(-) diff --git a/mm/slub.c b/mm/slub.c index f240e424c861..06f30c9ad361 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -2743,13 +2743,29 @@ static void *___slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node, c->page = page; check_new_page: - if (likely(!kmem_cache_debug(s) && pfmemalloc_match(page, gfpflags))) - goto load_freelist; - /* Only entered in the debug case */ - if (kmem_cache_debug(s) && - !alloc_debug_processing(s, page, freelist, addr)) - goto new_slab; /* Slab failed checks. Next slab needed */ + if (kmem_cache_debug(s)) { + if (!alloc_debug_processing(s, page, freelist, addr)) + /* Slab failed checks. Next slab needed */ + goto new_slab; + else + /* + * For debug case, we don't load freelist so that all + * allocations go through alloc_debug_processing() + */ + goto return_single; + } + + if (unlikely(!pfmemalloc_match(page, gfpflags))) + /* + * For !pfmemalloc_match() case we don't load freelist so that + * we don't make further mismatched allocations easier. + */ + goto return_single; + + goto load_freelist; + +return_single: deactivate_slab(s, page, get_freepointer(s, freelist), c); return freelist; -- 2.31.1