RAS/CEC: Check count_threshold unconditionally

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
This commit is contained in:
Borislav Petkov 2019-04-20 14:06:37 +02:00
parent 6d8e294bf5
commit de0e0624d8

View File

@ -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;
}
/* Add/refresh element generation and increment count */
ca->array[to] |= DECAY_MASK << COUNT_BITS;
ca->array[to]++;
/* Check action threshold and soft-offline, if reached. */
count = COUNT(ca->array[to]);
if (count < count_threshold) {
ca->array[to] |= (DECAY_MASK << COUNT_BITS);
ca->array[to]++;
ret = 0;
} else {
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)