Messages in this thread | | | Subject | Re: [PATCH 2/2] mm, page_owner: Skip unnecessary stack_trace entries | From | Prakash Gupta <> | Date | Fri, 1 Sep 2017 10:30:23 +0530 |
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On 8/31/2017 1:04 PM, Vlastimil Babka wrote: > 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?
Yes, that's correct.
> >> 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>
Thanks.
> >> --- >> 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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