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| author | Yang Jihong <yangjihong1@huawei.com> | 2022-07-09 03:50:21 +0200 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2022-07-26 21:02:13 +0200 |
| commit | e432947ef5500f0c89ab044e00ee7842d38bdb39 (patch) | |
| tree | 14cecd2ff9b0353a86e6e1a14f95d41f88faca3c /tools/include | |
| parent | perf kwork: Add workqueue kwork record support (diff) | |
| download | linux-e432947ef5500f0c89ab044e00ee7842d38bdb39.tar.xz linux-e432947ef5500f0c89ab044e00ee7842d38bdb39.zip | |
tools lib: Add list_last_entry_or_null()
Add list_last_entry_or_null() to get the last element from a list,
returns NULL if the list is empty.
Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Clarke <pc@us.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220709015033.38326-6-yangjihong1@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/include')
| -rw-r--r-- | tools/include/linux/list.h | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/tools/include/linux/list.h b/tools/include/linux/list.h index b2fc48d5478c..a4dfb6a7cc6a 100644 --- a/tools/include/linux/list.h +++ b/tools/include/linux/list.h @@ -385,6 +385,17 @@ static inline void list_splice_tail_init(struct list_head *list, (!list_empty(ptr) ? list_first_entry(ptr, type, member) : NULL) /** + * list_last_entry_or_null - get the last element from a list + * @ptr: the list head to take the element from. + * @type: the type of the struct this is embedded in. + * @member: the name of the list_head within the struct. + * + * Note that if the list is empty, it returns NULL. + */ +#define list_last_entry_or_null(ptr, type, member) \ + (!list_empty(ptr) ? list_last_entry(ptr, type, member) : NULL) + +/** * list_next_entry - get the next element in list * @pos: the type * to cursor * @member: the name of the list_head within the struct. |