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=-9.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,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 DF09DC04AB2 for ; Thu, 9 May 2019 18:10:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B6F4B2084E for ; Thu, 9 May 2019 18:10:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alien8.de header.i=@alien8.de header.b="k1m3b2sa" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727001AbfEISKR (ORCPT ); Thu, 9 May 2019 14:10:17 -0400 Received: from mail.skyhub.de ([5.9.137.197]:36996 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726796AbfEISJh (ORCPT ); Thu, 9 May 2019 14:09:37 -0400 Received: from zn.tnic (p200300EC2F0F5F0071783F241746291C.dip0.t-ipconnect.de [IPv6:2003:ec:2f0f:5f00:7178:3f24:1746:291c]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 03FE61EC0AD6; Thu, 9 May 2019 20:09:34 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1557425375; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=NkEC4473CGa7e8fIjNoC3X1SUXgaP3E6j+KdsWZpwGI=; b=k1m3b2saVzeK70i0Zc+svzcsCMtLoz9u/6G0XhnNTuEjjBqaPgdeZdOLSwkAtok3vOMT9x jzlXXcpyFlWLaTYeD49uG6SdwoL+UKtkVB6uKF0psIVjtbY9kzJFknqbLnScN5lCIl0BFI LGOml0JVdm+uTsrhRAzo+MzzTJjSKCs= From: Borislav Petkov To: Tony Luck Cc: linux-edac , LKML Subject: [PATCH 04/11] RAS/CEC: Check count_threshold unconditionally Date: Thu, 9 May 2019 20:09:19 +0200 Message-Id: <20190509180926.31932-5-bp@alien8.de> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190509180926.31932-1-bp@alien8.de> References: <20190509180926.31932-1-bp@alien8.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Borislav Petkov The count_threshold should be checked unconditionally, after insertion too, so that a count_threshold value of 1 can cause an immediate offlining. I.e., offline the page on the *first* error encountered. Add comments to make it clear what cec_add_elem() does, while at it. Reported-by: WANG Chao Signed-off-by: Borislav Petkov Cc: Tony Luck Cc: linux-edac@vger.kernel.org Link: https://lkml.kernel.org/r/20190418034115.75954-3-chao.wang@ucloud.cn --- drivers/ras/cec.c | 27 ++++++++++----------------- 1 file changed, 10 insertions(+), 17 deletions(-) diff --git a/drivers/ras/cec.c b/drivers/ras/cec.c index 1275907ff21c..73216b7f67be 100644 --- a/drivers/ras/cec.c +++ b/drivers/ras/cec.c @@ -294,6 +294,7 @@ int cec_add_elem(u64 pfn) ca->ces_entered++; + /* Array full, free the LRU slot. */ if (ca->n == MAX_ELEMS) WARN_ON(!del_lru_elem_unlocked(ca)); @@ -306,24 +307,17 @@ int cec_add_elem(u64 pfn) (void *)&ca->array[to], (ca->n - to) * sizeof(u64)); - ca->array[to] = (pfn << PAGE_SHIFT) | - (DECAY_MASK << COUNT_BITS) | 1; - + ca->array[to] = pfn << PAGE_SHIFT; ca->n++; - - ret = 0; - - goto decay; } - count = COUNT(ca->array[to]); - - if (count < count_threshold) { - ca->array[to] |= (DECAY_MASK << COUNT_BITS); - ca->array[to]++; + /* Add/refresh element generation and increment count */ + ca->array[to] |= DECAY_MASK << COUNT_BITS; + ca->array[to]++; - ret = 0; - } else { + /* Check action threshold and soft-offline, if reached. */ + count = COUNT(ca->array[to]); + if (count >= count_threshold) { u64 pfn = ca->array[to] >> PAGE_SHIFT; if (!pfn_valid(pfn)) { @@ -338,15 +332,14 @@ int cec_add_elem(u64 pfn) del_elem(ca, to); /* - * Return a >0 value to denote that we've reached the offlining - * threshold. + * Return a >0 value to callers, to denote that we've reached + * the offlining threshold. */ ret = 1; goto unlock; } -decay: ca->decay_count++; if (ca->decay_count >= CLEAN_ELEMS) -- 2.21.0