Tracing the event "fs_dax:dax_pmd_insert_mapping" with perf produces this warning: [fs_dax:dax_pmd_insert_mapping] unknown op '~'
It is printed in process_op (tools/lib/traceevent/event-parse.c) because '~' is parsed as a binary operator. perf reads the format of fs_dax:dax_pmd_insert_mapping ("print fmt") from /sys/kernel/debug/tracing/events/fs_dax/dax_pmd_insert_mapping/format . The format contains: ~(((u64) ~(~(((1UL) << 12)-1))) ^ \ interpreted as a binary operator by process_op(). This part is generated in the declaration of the event class dax_pmd_insert_mapping_class in include/trace/events/fs_dax.h : __print_flags_u64(__entry->pfn_val & PFN_FLAGS_MASK, "|", PFN_FLAGS_TRACE), This patch adds a pair of parentheses in the declaration of PFN_FLAGS_MASK to make sure that '~' is parsed as a unary operator by perf. The part of the format that was problematic is now: ~(((u64) (~(~(((1UL) << 12)-1)))) Now, all the '~' are parsed as unary operators. Cc: Dan Williams <dan.j.willi...@intel.com> Cc: "Steven Rostedt (VMware)" <rost...@goodmis.org> Cc: Arnaldo Carvalho de Melo <a...@redhat.com> Cc: "Tzvetomir Stoyanov (VMware)" <tz.stoya...@gmail.com> Cc: Namhyung Kim <namhy...@kernel.org> Cc: Ross Zwisler <zwis...@kernel.org> Cc: Elenie Godzaridis <arangradi...@gmail.com> Cc: linux-perf-us...@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Sebastien Boisvert <sebh...@videotron.qc.ca> --- include/linux/pfn_t.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/linux/pfn_t.h b/include/linux/pfn_t.h index 21713dc14ce2..673546ba7342 100644 --- a/include/linux/pfn_t.h +++ b/include/linux/pfn_t.h @@ -10,7 +10,7 @@ * PFN_DEV - pfn is not covered by system memmap by default * PFN_MAP - pfn has a dynamic page mapping established by a device driver */ -#define PFN_FLAGS_MASK (((u64) ~PAGE_MASK) << (BITS_PER_LONG_LONG - PAGE_SHIFT)) +#define PFN_FLAGS_MASK (((u64) (~PAGE_MASK)) << (BITS_PER_LONG_LONG - PAGE_SHIFT)) #define PFN_SG_CHAIN (1ULL << (BITS_PER_LONG_LONG - 1)) #define PFN_SG_LAST (1ULL << (BITS_PER_LONG_LONG - 2)) #define PFN_DEV (1ULL << (BITS_PER_LONG_LONG - 3)) -- 2.17.1