diff options
| author | Tejun Heo <tj@kernel.org> | 2015-09-29 12:47:53 -0400 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2015-10-12 10:31:13 -0600 |
| commit | d60d1bddd5b642711a237511845853755b25bf1f (patch) | |
| tree | e5790b6d703d30fcd8c92f5760fdcc0e165fc912 /mm/page-writeback.c | |
| parent | b817525a4a80c04e4ca44192d97a1ffa9f2be572 (diff) | |
| download | lwn-d60d1bddd5b642711a237511845853755b25bf1f.tar.gz lwn-d60d1bddd5b642711a237511845853755b25bf1f.zip | |
writeback: memcg dirty_throttle_control should be initialized with wb->memcg_completions
MDTC_INIT() is used to initialize dirty_throttle_control for memcg
domains. It used DTC_INIT_COMMON() to initialized mdtc->wb and
->wb_completions which is incorrect as DTC_INIT_COMMON() sets the
latter to wb->completions instead of wb->memcg_completions. This can
lead to wildly incorrect results when calculating the proportion of
dirty memory the memcg domain should get.
Remove DTC_INIT_COMMON() and update MDTC_INIT() to initialize
mdtc->wb_completions to wb->memcg_completions.
Signed-off-by: Tejun Heo <tj@kernel.org>
Fixes: c2aa723a6093 ("writeback: implement memcg writeback domain based throttling")
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'mm/page-writeback.c')
| -rw-r--r-- | mm/page-writeback.c | 20 |
1 files changed, 11 insertions, 9 deletions
diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 0f1a94e9f351..56c0bffa9f49 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -145,9 +145,6 @@ struct dirty_throttle_control { unsigned long pos_ratio; }; -#define DTC_INIT_COMMON(__wb) .wb = (__wb), \ - .wb_completions = &(__wb)->completions - /* * Length of period for aging writeout fractions of bdis. This is an * arbitrarily chosen number. The longer the period, the slower fractions will @@ -157,12 +154,16 @@ struct dirty_throttle_control { #ifdef CONFIG_CGROUP_WRITEBACK -#define GDTC_INIT(__wb) .dom = &global_wb_domain, \ - DTC_INIT_COMMON(__wb) +#define GDTC_INIT(__wb) .wb = (__wb), \ + .dom = &global_wb_domain, \ + .wb_completions = &(__wb)->completions + #define GDTC_INIT_NO_WB .dom = &global_wb_domain -#define MDTC_INIT(__wb, __gdtc) .dom = mem_cgroup_wb_domain(__wb), \ - .gdtc = __gdtc, \ - DTC_INIT_COMMON(__wb) + +#define MDTC_INIT(__wb, __gdtc) .wb = (__wb), \ + .dom = mem_cgroup_wb_domain(__wb), \ + .wb_completions = &(__wb)->memcg_completions, \ + .gdtc = __gdtc static bool mdtc_valid(struct dirty_throttle_control *dtc) { @@ -213,7 +214,8 @@ static void wb_min_max_ratio(struct bdi_writeback *wb, #else /* CONFIG_CGROUP_WRITEBACK */ -#define GDTC_INIT(__wb) DTC_INIT_COMMON(__wb) +#define GDTC_INIT(__wb) .wb = (__wb), \ + .wb_completions = &(__wb)->completions #define GDTC_INIT_NO_WB #define MDTC_INIT(__wb, __gdtc) |