From: Changhee Han <ch0.han@xxxxxxx> Subject: tools/vm/page_owner_sort.c: filter out unneeded line To see a sorted result from page_owner, there must be a tiresome preprocessing step before running page_owner_sort. This patch simply filters out lines which start with "PFN" while reading the page owner report. Link: http://lkml.kernel.org/r/20200429052940.16968-1-ch0.han@xxxxxxx Signed-off-by: Changhee Han <ch0.han@xxxxxxx> Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: Vlastimil Babka <vbabka@xxxxxxx> Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> Cc: Jonathan Corbet <corbet@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- Documentation/vm/page_owner.rst | 3 +-- tools/vm/page_owner_sort.c | 5 +++-- 2 files changed, 4 insertions(+), 4 deletions(-) --- a/Documentation/vm/page_owner.rst~tools-vm-page_owner_sort-filter-out-unneeded-line +++ a/Documentation/vm/page_owner.rst @@ -83,8 +83,7 @@ Usage 4) Analyze information from page owner:: cat /sys/kernel/debug/page_owner > page_owner_full.txt - grep -v ^PFN page_owner_full.txt > page_owner.txt - ./page_owner_sort page_owner.txt sorted_page_owner.txt + ./page_owner_sort page_owner_full.txt sorted_page_owner.txt See the result about who allocated each page in the ``sorted_page_owner.txt``. --- a/tools/vm/page_owner_sort.c~tools-vm-page_owner_sort-filter-out-unneeded-line +++ a/tools/vm/page_owner_sort.c @@ -4,8 +4,7 @@ * * Example use: * cat /sys/kernel/debug/page_owner > page_owner_full.txt - * grep -v ^PFN page_owner_full.txt > page_owner.txt - * ./page_owner_sort page_owner.txt sorted_page_owner.txt + * ./page_owner_sort page_owner_full.txt sorted_page_owner.txt * * See Documentation/vm/page_owner.rst */ @@ -38,6 +37,8 @@ int read_block(char *buf, int buf_size, while (buf_end - curr > 1 && fgets(curr, buf_end - curr, fin)) { if (*curr == '\n') /* empty line */ return curr - buf; + if (!strncmp(curr, "PFN", 3)) + continue; curr += strlen(curr); } _
