Messages in this thread | | | Subject | Re: [PATCH 2/2] mm, page_owner: Skip unnecessary stack_trace entries | From | Vlastimil Babka <> | Date | Thu, 31 Aug 2017 09:34:38 +0200 |
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On 08/30/2017 09:32 AM, Prakash Gupta wrote: > The page_owner stacktrace always begin as follows: > > [<ffffff987bfd48f4>] save_stack+0x40/0xc8 > [<ffffff987bfd4da8>] __set_page_owner+0x3c/0x6c
Hmm, on x86_64 it looks like this:
save_stack_trace+0x16/0x20 save_stack+0x43/0xe0 __set_page_owner+0x24/0x50
So after your patch there's still __set_page_owner. Seems x86 needs something similar to your arm64 patch 1/2?
> These two entries do not provide any useful information and limits the > available stacktrace depth. The page_owner stacktrace was skipping caller > function from stack entries but this was missed with commit f2ca0b557107 > ("mm/page_owner: use stackdepot to store stacktrace") > > Example page_owner entry after the patch: > > Page allocated via order 0, mask 0x8(ffffff80085fb714) > PFN 654411 type Movable Block 639 type CMA Flags 0x0(ffffffbe5c7f12c0) > [<ffffff9b64989c14>] post_alloc_hook+0x70/0x80 > ... > [<ffffff9b651216e8>] msm_comm_try_state+0x5f8/0x14f4 > [<ffffff9b6512486c>] msm_vidc_open+0x5e4/0x7d0 > [<ffffff9b65113674>] msm_v4l2_open+0xa8/0x224 > > Fixes: f2ca0b557107 ("mm/page_owner: use stackdepot to store stacktrace") > Signed-off-by: Prakash Gupta <guptap@codeaurora.org>
The patch itself improves the output regardless of whether we fix the x86 internals, so:
Acked-by: Vlastimil Babka <vbabka@suse.cz>
> --- > mm/page_owner.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/page_owner.c b/mm/page_owner.c > index 10d16fc45bd9..75b7c39bf1df 100644 > --- a/mm/page_owner.c > +++ b/mm/page_owner.c > @@ -139,7 +139,7 @@ static noinline depot_stack_handle_t save_stack(gfp_t flags) > .nr_entries = 0, > .entries = entries, > .max_entries = PAGE_OWNER_STACK_DEPTH, > - .skip = 0 > + .skip = 2 > }; > depot_stack_handle_t handle; > >
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