Messages in this thread | | | Subject | Re: [RESEND RFC v4 1/3] mm: add tracepoint for scanning pages | From | Vlastimil Babka <> | Date | Fri, 4 Sep 2015 18:07:06 +0200 |
| |
On 09/03/2015 10:51 PM, Ebru Akagunduz wrote: > Using static tracepoints, data of functions is recorded. > It is good to automatize debugging without doing a lot > of changes in the source code. > > This patch adds tracepoint for khugepaged_scan_pmd, > collapse_huge_page and __collapse_huge_page_isolate. > > Signed-off-by: Ebru Akagunduz <ebru.akagunduz@gmail.com> > Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> > Acked-by: Rik van Riel <riel@redhat.com> > --- > Changes in v2: > - Nothing changed > > Changes in v3: > - Print page address instead of vm_start (Vlastimil Babka) > - Define constants to specify exact tracepoint result (Vlastimil Babka) > > Changes in v4: > - Change the constant prefix with SCAN_ instead of MM_ (Vlastimil Babka) > - Move the constants into the enum (Vlastimil Babka) > - Move the constants from mm.h to huge_memory.c > (because only will be used in huge_memory.c) (Vlastimil Babka) > - Print pfn in tracepoints (Vlastimil Babka) > - Print scan result as string in tracepoint (Vlastimil Babka) > (I tried to make same things to print string like mm/compaction.c. > My patch does not print string, I skip something but could not see why)
How do you print the trace? Do you cat /sys/kernel/debug/tracing/trace_pipe or use some tool such as trace-cmd? I have just recently realized that tools don't print strings in the compaction tracepoints, which lead to a patch [1]. You could convert this patch in the same way and then it should work with tracing tools. Sorry for previously suggesting a wrong example to follow.
[1] https://lkml.org/lkml/2015/8/27/373
| |