From patchwork Thu Mar 14 07:20:27 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?b?SsO8cmdlbiBHcm/Dnw==?= X-Patchwork-Id: 13592159 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 lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 08E8AC54E5D for ; Thu, 14 Mar 2024 07:21:45 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.692910.1080609 (Exim 4.92) (envelope-from ) id 1rkfPG-0001VV-JI; Thu, 14 Mar 2024 07:21:38 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 692910.1080609; Thu, 14 Mar 2024 07:21:38 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1rkfPG-0001VO-GF; Thu, 14 Mar 2024 07:21:38 +0000 Received: by outflank-mailman (input) for mailman id 692910; Thu, 14 Mar 2024 07:21:37 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1rkfPF-0005rB-08 for xen-devel@lists.xenproject.org; Thu, 14 Mar 2024 07:21:37 +0000 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.223.131]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id 7d5675c0-e1d3-11ee-a1ee-f123f15fe8a2; Thu, 14 Mar 2024 08:21:35 +0100 (CET) Received: from imap1.dmz-prg2.suse.org (imap1.dmz-prg2.suse.org [10.150.64.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 101F41F79B; Thu, 14 Mar 2024 07:21:35 +0000 (UTC) Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id C38D513977; Thu, 14 Mar 2024 07:21:34 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id L25ELn6l8mV/DgAAD6G6ig (envelope-from ); Thu, 14 Mar 2024 07:21:34 +0000 X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 7d5675c0-e1d3-11ee-a1ee-f123f15fe8a2 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1710400895; 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=lVUg9sUvshZn0hcfy+zcEBYHChto2sM8ej1C5kH/2gA=; b=bCTeyhrUUqc9JD5BDVIVsaj3drWovyp3NBzB06q9GTGxzwLgDmX2VQaefJXGE/31hJSHo4 poM0XP+Ato6d3pg2Tn6TFGmEEYiO5fewWFNDLf5jkjfaiublYF5jZ89DSzqrU9ynQAkyY/ kDVyy2aKqlzsey9cnGYU0o0T1QkP/rQ= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1710400895; 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=lVUg9sUvshZn0hcfy+zcEBYHChto2sM8ej1C5kH/2gA=; b=bCTeyhrUUqc9JD5BDVIVsaj3drWovyp3NBzB06q9GTGxzwLgDmX2VQaefJXGE/31hJSHo4 poM0XP+Ato6d3pg2Tn6TFGmEEYiO5fewWFNDLf5jkjfaiublYF5jZ89DSzqrU9ynQAkyY/ kDVyy2aKqlzsey9cnGYU0o0T1QkP/rQ= From: Juergen Gross To: xen-devel@lists.xenproject.org Cc: Juergen Gross , Andrew Cooper , George Dunlap , Jan Beulich , Julien Grall , Stefano Stabellini , Wei Liu Subject: [PATCH v5 11/13] xen/spinlock: support higher number of cpus Date: Thu, 14 Mar 2024 08:20:27 +0100 Message-Id: <20240314072029.16937-12-jgross@suse.com> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20240314072029.16937-1-jgross@suse.com> References: <20240314072029.16937-1-jgross@suse.com> MIME-Version: 1.0 Authentication-Results: smtp-out2.suse.de; none X-Spamd-Result: default: False [1.90 / 50.00]; ARC_NA(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; R_MISSING_CHARSET(2.50)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; MIME_GOOD(-0.10)[text/plain]; BROKEN_CONTENT_TYPE(1.50)[]; RCVD_COUNT_THREE(0.00)[3]; DKIM_SIGNED(0.00)[suse.com:s=susede1]; RCPT_COUNT_SEVEN(0.00)[8]; MID_CONTAINS_FROM(1.00)[]; FUZZY_BLOCKED(0.00)[rspamd.com]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+]; RCVD_TLS_ALL(0.00)[]; BAYES_HAM(-3.00)[100.00%] Allow 16 bits per cpu number, which is the limit imposed by spinlock_tickets_t. This will allow up to 65535 cpus, while increasing only the size of recursive spinlocks in debug builds from 8 to 12 bytes. The current Xen limit of 4095 cpus is imposed by SPINLOCK_CPU_BITS being 12. There are machines available with more cpus than the current Xen limit, so it makes sense to have the possibility to use more cpus. Signed-off-by: Juergen Gross --- V5: - keep previous recursion limit (Julien Grall) --- xen/common/spinlock.c | 2 ++ xen/include/xen/spinlock.h | 20 ++++++++++---------- 2 files changed, 12 insertions(+), 10 deletions(-) diff --git a/xen/common/spinlock.c b/xen/common/spinlock.c index b28239f74d..5be48be082 100644 --- a/xen/common/spinlock.c +++ b/xen/common/spinlock.c @@ -481,7 +481,9 @@ bool _rspin_trylock(rspinlock_t *lock) /* Don't allow overflow of recurse_cpu field. */ BUILD_BUG_ON(NR_CPUS > SPINLOCK_NO_CPU); + BUILD_BUG_ON(SPINLOCK_CPU_BITS > sizeof(lock->recurse_cpu) * 8); BUILD_BUG_ON(SPINLOCK_RECURSE_BITS < 3); + BUILD_BUG_ON(SPINLOCK_MAX_RECURSE > ((1u << SPINLOCK_RECURSE_BITS) - 1)); check_lock(&lock->debug, true); diff --git a/xen/include/xen/spinlock.h b/xen/include/xen/spinlock.h index 1b50a7e6a0..984da6d4c9 100644 --- a/xen/include/xen/spinlock.h +++ b/xen/include/xen/spinlock.h @@ -8,16 +8,16 @@ #include #include -#define SPINLOCK_CPU_BITS 12 +#define SPINLOCK_CPU_BITS 16 #ifdef CONFIG_DEBUG_LOCKS union lock_debug { - uint16_t val; -#define LOCK_DEBUG_INITVAL 0xffff + uint32_t val; +#define LOCK_DEBUG_INITVAL 0xffffffff struct { - uint16_t cpu:SPINLOCK_CPU_BITS; -#define LOCK_DEBUG_PAD_BITS (14 - SPINLOCK_CPU_BITS) - uint16_t :LOCK_DEBUG_PAD_BITS; + uint32_t cpu:SPINLOCK_CPU_BITS; +#define LOCK_DEBUG_PAD_BITS (30 - SPINLOCK_CPU_BITS) + uint32_t :LOCK_DEBUG_PAD_BITS; bool irq_safe:1; bool unseen:1; }; @@ -211,11 +211,11 @@ typedef struct spinlock { typedef struct rspinlock { spinlock_tickets_t tickets; - uint16_t recurse_cpu:SPINLOCK_CPU_BITS; + uint16_t recurse_cpu; #define SPINLOCK_NO_CPU ((1u << SPINLOCK_CPU_BITS) - 1) -#define SPINLOCK_RECURSE_BITS (16 - SPINLOCK_CPU_BITS) - uint16_t recurse_cnt:SPINLOCK_RECURSE_BITS; -#define SPINLOCK_MAX_RECURSE ((1u << SPINLOCK_RECURSE_BITS) - 1) +#define SPINLOCK_RECURSE_BITS 8 + uint8_t recurse_cnt; +#define SPINLOCK_MAX_RECURSE 15 union lock_debug debug; #ifdef CONFIG_DEBUG_LOCK_PROFILE struct lock_profile *profile;