From: Borislav Petkov <bp@alien8.de>
To: Tony Luck <tony.luck@intel.com>
Cc: linux-edac <linux-edac@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: [PATCH 04/11] RAS/CEC: Check count_threshold unconditionally
Date: Thu, 9 May 2019 20:09:19 +0200 [thread overview]
Message-ID: <20190509180926.31932-5-bp@alien8.de> (raw)
In-Reply-To: <20190509180926.31932-1-bp@alien8.de>
From: Borislav Petkov <bp@suse.de>
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 <chao.wang@ucloud.cn>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Tony Luck <tony.luck@intel.com>
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
next prev parent reply other threads:[~2019-05-09 18:10 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-09 18:09 [PATCH 00/11] RAS/CEC: Fixes and cleanups Borislav Petkov
2019-05-09 18:09 ` [PATCH 01/11] RAS/CEC: Fix binary search function Borislav Petkov
2019-05-09 18:09 ` [PATCH 02/11] RAS/CEC: Convert the timer callback to a workqueue Borislav Petkov
2019-05-09 18:09 ` [PATCH 03/11] RAS/CEC: Fix pfn insertion Borislav Petkov
2019-05-09 18:09 ` Borislav Petkov [this message]
2019-05-09 18:09 ` [PATCH 05/11] RAS/CEC: Do not set decay value on error Borislav Petkov
2019-05-09 18:09 ` [PATCH 06/11] RAS/CEC: Fix potential memory leak Borislav Petkov
2019-05-09 18:09 ` [PATCH 07/11] RAS/CEC: Sanity-check array on every insertion Borislav Petkov
2019-05-09 18:09 ` [PATCH 08/11] RAS/CEC: Rename count_threshold to action_threshold Borislav Petkov
2019-05-09 18:09 ` [PATCH 09/11] RAS/CEC: Dump the different array element sections Borislav Petkov
2019-05-09 18:09 ` [PATCH 10/11] RAS/CEC: Add CONFIG_RAS_CEC_DEBUG and move CEC debug features there Borislav Petkov
2019-05-09 18:09 ` [PATCH 11/11] RAS/CEC: Add copyright Borislav Petkov
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