From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E33C12EAEA; Fri, 24 Nov 2023 19:04:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Vd8eS4eD" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 47341C433C8; Fri, 24 Nov 2023 19:04:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1700852663; bh=/MYKxYGQNeky6nF2ANCm3RPE/av8LD0dFxgRUTel+Is=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Vd8eS4eDQLgYbBZW4ptEwRTQhbhe3fjgyaymJ7/We4FSdIeUj/vuZAspjDiSsi1y4 RxQ7ZqxcFLDvMs6S8ECIawFBaYzDAo4sH00hNEQ5030xvFCl7DEwiusGtOLsZvetSE mNVILlJyqlx4ND/ddURWA7IhheP4wbarStkhIrHU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jan Beulich , Juergen Gross , Oleksandr Tyshchenko , Sasha Levin Subject: [PATCH 5.10 074/193] xen/events: fix delayed eoi list handling Date: Fri, 24 Nov 2023 17:53:21 +0000 Message-ID: <20231124171950.194063199@linuxfoundation.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20231124171947.127438872@linuxfoundation.org> References: <20231124171947.127438872@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Juergen Gross [ Upstream commit 47d970204054f859f35a2237baa75c2d84fcf436 ] 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 Signed-off-by: Juergen Gross Signed-off-by: Sasha Levin --- 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 52891546e6973..24e39984914fe 100644 --- a/drivers/xen/events/events_base.c +++ b/drivers/xen/events/events_base.c @@ -551,7 +551,9 @@ 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); -- 2.42.0