Fix two build problems: 1. implicit declaration of function 'cgroup_ino'. 2. unused variable 'stats'. After this fix, No build problem is found when CGROUPS is disabled. The wb_stats could be successfully retrieved when CGROUP_WRITEBACK is disabled: cat wb_stats WbCgIno: 1 WbWriteback: 0 kB WbReclaimable: 685440 kB WbDirtyThresh: 195530960 kB WbDirtied: 691488 kB WbWritten: 6048 kB WbWriteBandwidth: 102400 kBps b_dirty: 2 b_io: 0 b_more_io: 0 b_dirty_time: 0 state: 5 cat wb_stats WbCgIno: 1 WbWriteback: 0 kB WbReclaimable: 818944 kB WbDirtyThresh: 195527484 kB WbDirtied: 824992 kB WbWritten: 6048 kB WbWriteBandwidth: 102400 kBps b_dirty: 2 b_io: 0 b_more_io: 0 b_dirty_time: 0 state: 5 Signed-off-by: Kemeng Shi <shikemeng@xxxxxxxxxxxxxxx> --- mm/backing-dev.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/mm/backing-dev.c b/mm/backing-dev.c index 6ecd11bdce6e..e61bbb1bd622 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -172,7 +172,11 @@ static void wb_stats_show(struct seq_file *m, struct bdi_writeback *wb, "b_more_io: %10lu\n" "b_dirty_time: %10lu\n" "state: %10lx\n\n", +#ifdef CONFIG_CGROUP_WRITEBACK cgroup_ino(wb->memcg_css->cgroup), +#else + 1ul, +#endif K(stats->nr_writeback), K(stats->nr_reclaimable), K(stats->wb_thresh), @@ -192,7 +196,6 @@ static int cgwb_debug_stats_show(struct seq_file *m, void *v) unsigned long background_thresh; unsigned long dirty_thresh; struct bdi_writeback *wb; - struct wb_stats stats; global_dirty_limits(&background_thresh, &dirty_thresh); -- 2.30.0