Commit-ID: de0e0624d86ff9fc512dedb297f8978698abf21a Gitweb: https://git.kernel.org/tip/de0e0624d86ff9fc512dedb297f8978698abf21a Author: Borislav Petkov <b...@suse.de> AuthorDate: Sat, 20 Apr 2019 14:06:37 +0200 Committer: Borislav Petkov <b...@suse.de> CommitDate: Sat, 8 Jun 2019 17:33:10 +0200
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.w...@ucloud.cn> Signed-off-by: Borislav Petkov <b...@suse.de> Cc: Tony Luck <tony.l...@intel.com> Cc: linux-e...@vger.kernel.org Link: https://lkml.kernel.org/r/20190418034115.75954-3-chao.w...@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 f5795adc5a6e..73a975c26f9f 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)
