From patchwork Mon Oct 16 06:28:25 2023 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: 13422564 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 20050CDB465 for ; Mon, 16 Oct 2023 06:28:53 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.617224.959645 (Exim 4.92) (envelope-from ) id 1qsH5o-0005jl-5p; Mon, 16 Oct 2023 06:28:44 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 617224.959645; Mon, 16 Oct 2023 06:28:44 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1qsH5o-0005je-2Y; Mon, 16 Oct 2023 06:28:44 +0000 Received: by outflank-mailman (input) for mailman id 617224; Mon, 16 Oct 2023 06:28:42 +0000 Received: from se1-gles-sth1-in.inumbo.com ([159.253.27.254] helo=se1-gles-sth1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1qsH5m-0005jO-EN for xen-devel@lists.xenproject.org; Mon, 16 Oct 2023 06:28:42 +0000 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by se1-gles-sth1.inumbo.com (Halon) with ESMTPS id 3f7e7285-6bed-11ee-98d4-6d05b1d4d9a1; Mon, 16 Oct 2023 08:28:41 +0200 (CEST) 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-out2.suse.de (Postfix) with ESMTPS id B07521FEA9; Mon, 16 Oct 2023 06:28:40 +0000 (UTC) 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 7FACD138EF; Mon, 16 Oct 2023 06:28:40 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id ++vdHRjYLGWEQQAAMHmgww (envelope-from ); Mon, 16 Oct 2023 06:28:40 +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: 3f7e7285-6bed-11ee-98d4-6d05b1d4d9a1 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1697437720; 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=hBgTSni+I3ppK49nD/tnBJmLcv3aLmPun9In8njDCy4=; b=a2PTjcLx1p3n+4hZ7IAIhiXuz/Snwz7VPD7EqdwyTSPjCbWUn8tdXHUncYrCMvyKRL0rcT r9mYbUivhp5VqGCYn9sjH+CjQFqXlFJoxaqnbswv1xpSd/mF8WodAQMg6vXmRBWH2jFjc5 3lqtPANzQIFlmSNxeB+rjvNRm8UAdM0= From: Juergen Gross To: linux-kernel@vger.kernel.org Cc: Juergen Gross , Stefano Stabellini , Oleksandr Tyshchenko , xen-devel@lists.xenproject.org, Jan Beulich Subject: [PATCH 1/7] xen/events: fix delayed eoi list handling Date: Mon, 16 Oct 2023 08:28:25 +0200 Message-Id: <20231016062831.20630-2-jgross@suse.com> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20231016062831.20630-1-jgross@suse.com> References: <20231016062831.20630-1-jgross@suse.com> MIME-Version: 1.0 Authentication-Results: smtp-out2.suse.de; none X-Spamd-Result: default: False [-3.05 / 50.00]; ARC_NA(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; BAYES_SPAM(0.05)[55.71%]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; R_MISSING_CHARSET(2.50)[]; MIME_GOOD(-0.10)[text/plain]; REPLY(-4.00)[]; BROKEN_CONTENT_TYPE(1.50)[]; RCPT_COUNT_FIVE(0.00)[6]; NEURAL_HAM_LONG(-3.00)[-1.000]; DKIM_SIGNED(0.00)[suse.com:s=susede1]; NEURAL_HAM_SHORT(-1.00)[-1.000]; MID_CONTAINS_FROM(1.00)[]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+]; RCVD_COUNT_TWO(0.00)[2]; RCVD_TLS_ALL(0.00)[] When delaying eoi handling of events, the related elements are queued into the percpu lateeoi list. In case the list isn't empty, the elements should be sorted by the time when eoi handling is to happen. Unfortunately a new element will never be queued at the start of the list, even if it has a handling time lower than all other list elements. Fix that by handling that case the same way as for an empty list. Fixes: e99502f76271 ("xen/events: defer eoi in case of excessive number of events") Reported-by: Jan Beulich Signed-off-by: Juergen Gross Reviewed-by: Oleksandr Tyshchenko --- drivers/xen/events/events_base.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c index 1b2136fe0fa5..0e458b1c0c8c 100644 --- a/drivers/xen/events/events_base.c +++ b/drivers/xen/events/events_base.c @@ -601,7 +601,9 @@ static void lateeoi_list_add(struct irq_info *info) spin_lock_irqsave(&eoi->eoi_list_lock, flags); - if (list_empty(&eoi->eoi_list)) { + elem = list_first_entry_or_null(&eoi->eoi_list, struct irq_info, + eoi_list); + if (!elem || info->eoi_time < elem->eoi_time) { list_add(&info->eoi_list, &eoi->eoi_list); mod_delayed_work_on(info->eoi_cpu, system_wq, &eoi->delayed, delay);