From: Yang Yang <yang.yang29@xxxxxxxxxx> Subject: delayacct: fix incomplete disable operation when switch enable to disable When a task is created after delayacct is enabled, kernel will do all the delay accountings for that task. The problems is if user disables delayacct by set /proc/sys/kernel/task_delayacct to zero, only blkio delay accounting is disabled. Now disable all the kinds of delay accountings when /proc/sys/kernel/task_delayacct sets to zero. Link: https://lkml.kernel.org/r/20211123140342.32962-1-ran.xiaokai@xxxxxxxxxx Signed-off-by: Yang Yang <yang.yang29@xxxxxxxxxx> Reported-by: Zeal Robot <zealci@xxxxxxxxxx> Cc: Balbir Singh <bsingharora@xxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/delayacct.h | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) --- a/include/linux/delayacct.h~delayacct-fix-incomplete-disable-operation-when-switch-enable-to-disable +++ a/include/linux/delayacct.h @@ -131,36 +131,54 @@ static inline __u64 delayacct_blkio_tick static inline void delayacct_freepages_start(void) { + if (!static_branch_unlikely(&delayacct_key)) + return; + if (current->delays) __delayacct_freepages_start(); } static inline void delayacct_freepages_end(void) { + if (!static_branch_unlikely(&delayacct_key)) + return; + if (current->delays) __delayacct_freepages_end(); } static inline void delayacct_thrashing_start(void) { + if (!static_branch_unlikely(&delayacct_key)) + return; + if (current->delays) __delayacct_thrashing_start(); } static inline void delayacct_thrashing_end(void) { + if (!static_branch_unlikely(&delayacct_key)) + return; + if (current->delays) __delayacct_thrashing_end(); } static inline void delayacct_swapin_start(void) { + if (!static_branch_unlikely(&delayacct_key)) + return; + if (current->delays) __delayacct_swapin_start(); } static inline void delayacct_swapin_end(void) { + if (!static_branch_unlikely(&delayacct_key)) + return; + if (current->delays) __delayacct_swapin_end(); } _
