On Thu, Aug 19, 2021 at 11:48 PM HORIGUCHI NAOYA(堀口 直也) <naoya.horiguchi@xxxxxxx> wrote: > > On Wed, Aug 18, 2021 at 10:41:16PM -0700, Yang Shi wrote: > > Currently just very simple message is shown for unhandlable page, e.g. > > non-LRU page, like: > > soft_offline: 0x1469f2: unknown non LRU page type 5ffff0000000000 () > > > > It is not very helpful for further debug, calling dump_page() could show > > more useful information. > > > > Calling dump_page() in get_any_page() in order to not duplicate the call > > in a couple of different places. It may be called with pcp disabled and > > holding memory hotplug lock, it should be not a big deal since hwpoison > > handler is not called very often. > > > > Suggested-by: Matthew Wilcox <willy@xxxxxxxxxxxxx> > > Cc: Naoya Horiguchi <naoya.horiguchi@xxxxxxx> > > Cc: Oscar Salvador <osalvador@xxxxxxx> > > Signed-off-by: Yang Shi <shy828301@xxxxxxxxx> > > --- > > mm/memory-failure.c | 3 +++ > > 1 file changed, 3 insertions(+) > > > > diff --git a/mm/memory-failure.c b/mm/memory-failure.c > > index 7cfa134b1370..60df8fcd0444 100644 > > --- a/mm/memory-failure.c > > +++ b/mm/memory-failure.c > > @@ -1228,6 +1228,9 @@ static int get_any_page(struct page *p, unsigned long flags) > > ret = -EIO; > > } > > out: > > + if (ret == -EIO) > > + dump_page(p, "hwpoison: unhandlable page"); > > + > > I feel that 4 callers of get_hwpoison_page() are in the different context, > so it might be better to consider them separately to add dump_page() or not. > soft_offline_page() still prints out "%s: %#lx: unknown page type: %lx (%pGp)" No strong opinion to keep or remove it. > message, which might be duplicate so this printk() may be dropped. > In memory_failure_hugetlb() and memory_failure(), we can call dump_page() after > action_result(). unpoison_memory() doesn't need dump_page() at all because > it's related to already hwpoisoned page. I don't have a strong opinion either to have the dump_page() called either before action or after action, it just moves around the dumped page information around that printk. For unpoison_memory(), I think it is harmless to have dump_page() called, right? If get_hwpoison_page() can't return -EIO, then the dump_page() won't be called at all, if it is possible then this is exactly why we call dump_page() to help debug. So IMHO calling dump_page() in get_any_page when -EIO is returned could work for all the cases well and avoid duplicating the call. > > Thanks, > Naoya Horiguchi
