On Sun, Aug 22, 2021 at 10:05 PM HORIGUCHI NAOYA(堀口 直也) <naoya.horiguchi@xxxxxxx> wrote: > > On Fri, Aug 20, 2021 at 11:40:24AM -0700, Yang Shi wrote: > > 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. > > Reading the explanation below, I think that calling dump_page() in the > original place is fine. So let's remove "else if (ret == 0)" block in > soft_offline_page(). The "else if (ret == 0)" block is used to handle free page IIUC. I'm supposed you mean the "else if (ret == -EIO)" block which just calls printk. > > > > > > 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. > > Fair enough. So could you repost 3/3 with the above change in soft_offline_page()? > > Thanks, > Naoya Horiguchi
