From nobody Mon Feb 9 17:21:53 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 951A0C001B0 for ; Tue, 8 Aug 2023 16:35:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233117AbjHHQfe (ORCPT ); Tue, 8 Aug 2023 12:35:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36002 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232906AbjHHQea (ORCPT ); Tue, 8 Aug 2023 12:34:30 -0400 Received: from smtp-out1.suse.de (smtp-out1.suse.de [IPv6:2001:67c:2178:6::1c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F01B990AD for ; Tue, 8 Aug 2023 08:52:31 -0700 (PDT) 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 7C5062248B; Tue, 8 Aug 2023 09:53:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1691488433; 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=19m9+YAryd9zQqOJKLPS0ScJg55yhuc9Zn7O2SmAkY8=; b=0ypz/M4hFEYVg3RIkyKTZpGOtO0OELdvePk4KsvNp0QXKtSQ1NTkwvJ6x9bkVpsk5ACEo+ VdhEFCaw7TRHrCXiaOhP4fR0hWTfeBY2vexIA+Fg3uiY/xr+RGb+kCzEL8ZCXD6x0fD/My 6dCsKBwvmBeEB1+gOW5PonTGZTXEndk= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1691488433; 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=19m9+YAryd9zQqOJKLPS0ScJg55yhuc9Zn7O2SmAkY8=; b=gHwsy0hibpgfl2awLPIMsMc4dKqncic8vqqIN/UioyCepHOo4bgnZRyoxdFoRXKIOTGPXa oVyI5GXsppN4AdBQ== 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 53972139E9; Tue, 8 Aug 2023 09:53:53 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id eKi8E7EQ0mSBJQAAMHmgww (envelope-from ); Tue, 08 Aug 2023 09:53:53 +0000 From: Vlastimil Babka To: "Liam R. Howlett" , Matthew Wilcox , Christoph Lameter , David Rientjes , Pekka Enberg , Joonsoo Kim Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>, Roman Gushchin , linux-mm@kvack.org, linux-kernel@vger.kernel.org, patches@lists.linux.dev, Vlastimil Babka Subject: [RFC v1 5/5] maple_tree: replace preallocation with slub percpu array prefill Date: Tue, 8 Aug 2023 11:53:48 +0200 Message-ID: <20230808095342.12637-12-vbabka@suse.cz> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230808095342.12637-7-vbabka@suse.cz> References: <20230808095342.12637-7-vbabka@suse.cz> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" With the percpu array we can try not doing the preallocations in maple tree, and instead make sure the percpu array is prefilled, and using GFP_ATOMIC in places that relied on the preallocation (in case we miss or fail trylock on the array), i.e. mas_store_prealloc(). For now simply add __GFP_NOFAIL there as well. First I tried to change mas_node_count_gfp() to not preallocate anything anywhere, but that lead to warns and panics, even though the other caller mas_node_count() uses GFP_NOWAIT | __GFP_NOWARN so it has no guarantees... So I changed just mas_preallocate(). I let it still to truly preallocate a single node, but maybe it's not necessary? --- lib/maple_tree.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/lib/maple_tree.c b/lib/maple_tree.c index 7a8e7c467d7c..5a209d88c318 100644 --- a/lib/maple_tree.c +++ b/lib/maple_tree.c @@ -5534,7 +5534,12 @@ void mas_store_prealloc(struct ma_state *mas, void *= entry) =20 mas_wr_store_setup(&wr_mas); trace_ma_write(__func__, mas, 0, entry); + +retry: mas_wr_store_entry(&wr_mas); + if (unlikely(mas_nomem(mas, GFP_ATOMIC | __GFP_NOFAIL))) + goto retry; + MAS_WR_BUG_ON(&wr_mas, mas_is_err(mas)); mas_destroy(mas); } @@ -5550,9 +5555,10 @@ EXPORT_SYMBOL_GPL(mas_store_prealloc); int mas_preallocate(struct ma_state *mas, gfp_t gfp) { int ret; + int count =3D 1 + mas_mt_height(mas) * 3; =20 - mas_node_count_gfp(mas, 1 + mas_mt_height(mas) * 3, gfp); - mas->mas_flags |=3D MA_STATE_PREALLOC; + mas_node_count_gfp(mas, 1, gfp); + kmem_cache_prefill_percpu_array(maple_node_cache, count, gfp); if (likely(!mas_is_err(mas))) return 0; =20 --=20 2.41.0