Re: [PATCH] tools lib traceevent: add checks for returned EVENT_ERROR type

Namhyung Kim
2015-08-09T02:41:15Z

Hi Dean,

On Fri, Aug 07, 2015 at 08:02:25AM -0500, Dean Nelson wrote:
> On 08/07/2015 07:16 AM, Namhyung Kim wrote:
> >Hi,
> >
> >On Fri, Aug 7, 2015 at 7:59 PM, Jiri Olsa <jolsa@redhat.com> wrote:
> >>On Mon, Aug 03, 2015 at 01:08:05PM -0400, Dean Nelson wrote:
> >>>Running the following perf-stat command on an arm64 system produces the
> >>>following result...
> >>>
> >>> [root@aarch64 ~]# perf stat -e kmem:mm_page_alloc -a sleep 1
> >>> Warning: [kmem:mm_page_alloc] function sizeof not defined
> >>> Warning: Error: expected type 4 but read 0
> >>> Segmentation fault
> >
> >Oops,
> >
> >
> >>> [root@aarch64 ~]#
> >>
> >>hum, what kernel are you running on? I dont see that warning
> >>on my system:
> >>
> >>[jolsa@krava perf]$ sudo ./perf stat -e kmem:mm_page_alloc -a sleep 1
> >>
> >> Performance counter stats for 'system wide':
> >>
> >> 227 kmem:mm_page_alloc
> >>
> >> 1.000762466 seconds time elapsed
> >>
> >>Cc-ing Namhyung
> >
> >Yeah, it seems his kernel has sizeof() somewhere in the event format.
> >Anyway, it's not good to see a segfault.
> >
> >Dean, could you share your event format file?
> >
> > $ sudo cat /sys/kernel/debug/tracing/events/kmem/mm_page_alloc/format
>
> Sure, I've attached it. See my other email in reply to jirka's question
> about what kernel I was running on, for some details about where the
> sizeof operator comes from.

Thanks for the explanation. It seems there's a problem in processing
'?' operator. I'll take a look at it.

Thanks,
Namhyung

> name: mm_page_alloc
> ID: 360
> format:
> field:unsigned short common_type; offset:0; size:2; signed:0;
> field:unsigned char common_flags; offset:2; size:1; signed:0;
> field:unsigned char common_preempt_count; offset:3; size:1; signed:0;
> field:int common_pid; offset:4; size:4; signed:1;
>
> field:unsigned long pfn; offset:8; size:8; signed:0;
> field:unsigned int order; offset:16; size:4; signed:0;
> field:gfp_t gfp_flags; offset:20; size:4; signed:0;
> field:int migratetype; offset:24; size:4; signed:1;
>
> print fmt: "page=%p pfn=%lu order=%d migratetype=%d gfp_flags=%s", REC->pfn != -1UL ? (((struct page *)((((0xffffffffffffffffUL) << ((42) - 1)) - (1UL << ((16 - 3) * 2 + 3)) - (((((1UL << ((42) - 16)) * sizeof(struct page))) + ((typeof(((1UL << ((42) - 16)) * sizeof(struct page))))(((1UL << ((16 - 3) * 2 + 3)))) - 1)) & ~((typeof(((1UL << ((42) - 16)) * sizeof(struct page))))(((1UL << ((16 - 3) * 2 + 3)))) - 1)) - 0x00010000) + 0x00010000)) + (REC->pfn)) : ((void *)0), REC->pfn != -1UL ? REC->pfn : 0, REC->order, REC->migratetype, (REC->gfp_flags) ? __print_flags(REC->gfp_flags, "|", {(unsigned long)(((((( gfp_t)0x10u) | (( gfp_t)0x40u) | (( gfp_t)0x80u) | (( gfp_t)0x20000u)) | (( gfp_t)0x02u)) | (( gfp_t)0x08u)) | (( gfp_t)0x4000u) | (( gfp_t)0x10000u) | (( gfp_t)0x1000u) | (( gfp_t)0x200u) | (( gfp_t)0x400000u)), "GFP_TRANSHUGE"}, {(unsigned long)((((( gfp_t)0x10u) | (( gfp_t)0x40u) | (( gfp_t)0x80u) | (( gfp_t)0x20000u)) | (( gfp_t)0x02u)) | (( gfp_t)0x08u)), "GFP_HIGHUSER_MOVABLE"}, {(unsigned long)(((( gfp_t)0x10u) | (( gfp_t)0x40u) | (( gfp_t)0x80u) | (( gfp_t)0x20000u)) | (( gfp_t)0x02u)), "GFP_HIGHUSER"}, {(unsigned long)((( gfp_t)0x10u) | (( gfp_t)0x40u) | (( gfp_t)0x80u) | (( gfp_t)0x20000u)), "GFP_USER"}, {(unsigned long)((( gfp_t)0x10u) | (( gfp_t)0x40u) | (( gfp_t)0x80u) | (( gfp_t)0x80000u)), "GFP_TEMPORARY"}, {(unsigned long)((( gfp_t)0x10u) | (( gfp_t)0x40u) | (( gfp_t)0x80u)), "GFP_KERNEL"}, {(unsigned long)((( gfp_t)0x10u) | (( gfp_t)0x40u)), "GFP_NOFS"}, {(unsigned long)((( gfp_t)0x20u)), "GFP_ATOMIC"}, {(unsigned long)((( gfp_t)0x10u)), "GFP_NOIO"}, {(unsigned long)(( gfp_t)0x20u), "GFP_HIGH"}, {(unsigned long)(( gfp_t)0x10u), "GFP_WAIT"}, {(unsigned long)(( gfp_t)0x40u), "GFP_IO"}, {(unsigned long)(( gfp_t)0x100u), "GFP_COLD"}, {(unsigned long)(( gfp_t)0x200u), "GFP_NOWARN"}, {(unsigned long)(( gfp_t)0x400u), "GFP_REPEAT"}, {(unsigned long)(( gfp_t)0x800u), "GFP_NOFAIL"}, {(unsigned long)(( gfp_t)0x1000u), "GFP_NORETRY"}, {(unsigned long)(( gfp_t)0x4000u), "GFP_COMP"}, {(unsigned long)(( gfp_t)0x8000u), "GFP_ZERO"}, {(unsigned long)(( gfp_t)0x10000u), "GFP_NOMEMALLOC"}, {(unsigned long)(( gfp_t)0x2000u), "GFP_MEMALLOC"}, {(unsigned long)(( gfp_t)0x20000u), "GFP_HARDWALL"}, {(unsigned long)(( gfp_t)0x40000u), "GFP_THISNODE"}, {(unsigned long)(( gfp_t)0x80000u), "GFP_RECLAIMABLE"}, {(unsigned long)(( gfp_t)0x08u), "GFP_MOVABLE"}, {(unsigned long)(( gfp_t)0x200000u), "GFP_NOTRACK"}, {(unsigned long)(( gfp_t)0x400000u), "GFP_NO_KSWAPD"}, {(unsigned long)(( gfp_t)0x800000u), "GFP_OTHER_NODE"} ) : "GFP_NOWAIT"