diff options
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/memory-failure.c | 31 |
1 files changed, 18 insertions, 13 deletions
diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 757f6b0accf..eebb9d8efae 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -7,21 +7,26 @@ * Free Software Foundation. * * High level machine check handler. Handles pages reported by the - * hardware as being corrupted usually due to a 2bit ECC memory or cache + * hardware as being corrupted usually due to a multi-bit ECC memory or cache * failure. + * + * In addition there is a "soft offline" entry point that allows stop using + * not-yet-corrupted-by-suspicious pages without killing anything. * * Handles page cache pages in various states. The tricky part - * here is that we can access any page asynchronous to other VM - * users, because memory failures could happen anytime and anywhere, - * possibly violating some of their assumptions. This is why this code - * has to be extremely careful. Generally it tries to use normal locking - * rules, as in get the standard locks, even if that means the - * error handling takes potentially a long time. - * - * The operation to map back from RMAP chains to processes has to walk - * the complete process list and has non linear complexity with the number - * mappings. In short it can be quite slow. But since memory corruptions - * are rare we hope to get away with this. + * here is that we can access any page asynchronously in respect to + * other VM users, because memory failures could happen anytime and + * anywhere. This could violate some of their assumptions. This is why + * this code has to be extremely careful. Generally it tries to use + * normal locking rules, as in get the standard locks, even if that means + * the error handling takes potentially a long time. + * + * There are several operations here with exponential complexity because + * of unsuitable VM data structures. For example the operation to map back + * from RMAP chains to processes has to walk the complete process list and + * has non linear complexity with the number. But since memory corruptions + * are rare we hope to get away with this. This avoids impacting the core + * VM. */ /* @@ -78,7 +83,7 @@ static int hwpoison_filter_dev(struct page *p) return 0; /* - * page_mapping() does not accept slab page + * page_mapping() does not accept slab pages. */ if (PageSlab(p)) return -EINVAL; |