The patch titled Subject: mm, hwpoison: add comment describing when to add new cases has been removed from the -mm tree. Its filename was mm-hwpoison-add-comment-describing-when-to-add-new-cases.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Andi Kleen <ak@xxxxxxxxxxxxxxx> Subject: mm, hwpoison: add comment describing when to add new cases Here's another comment fix for hwpoison. It describes the "guiding principle" on when to add new memory error recovery code. Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx> Acked-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/memory-failure.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff -puN mm/memory-failure.c~mm-hwpoison-add-comment-describing-when-to-add-new-cases mm/memory-failure.c --- a/mm/memory-failure.c~mm-hwpoison-add-comment-describing-when-to-add-new-cases +++ a/mm/memory-failure.c @@ -20,6 +20,14 @@ * 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. + * + * It can be very tempting to add handling for obscure cases here. + * In general any code for handling new cases should only be added iff: + * - You know how to test it. + * - You have a test that can be added to mce-test + * https://git.kernel.org/cgit/utils/cpu/mce/mce-test.git/ + * - The case actually shows up as a frequent (top 10) page state in + * tools/vm/page-types when running a real workload. * * There are several operations here with exponential complexity because * of unsuitable VM data structures. For example the operation to map back _ Patches currently in -mm which might be from ak@xxxxxxxxxxxxxxx are origin.patch linux-next.patch do_shared_fault-check-that-mmap_sem-is-held.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html