Greentime Hu ed48b297fe riscv: Enable context tracking ... This patch implements and enables context tracking for riscv (which is a prerequisite for CONFIG_NO_HZ_FULL support) It adds checking for previous state in the entry that all excepttions and interrupts goes to and calls context_tracking_user_exit() if it comes from user space. It also calls context_tracking_user_enter() if it will return to user space before restore_all. This patch is tested with the dynticks-testing testcase in qemu-system-riscv64 virt machine and Unleashed board. git://git.kernel.org/pub/scm/linux/kernel/git/frederic/dynticks-testing.git We can see the log here. The tick got mostly stopped during the execution of the user loop. _-----=> irqs-off / _----=> need-resched | / _---=> hardirq/softirq || / _--=> preempt-depth ||| / delay TASK-PID CPU# |||| TIMESTAMP FUNCTION | | | |||| | | <idle>-0 [001] d..2 604.183512: sched_switch: prev_comm=swapper/1 prev_pid=0 prev_prio=120 prev_state=R ==> next_comm=taskset next_pid=273 next_prio=120 user_loop-273 [001] d.h1 604.184788: hrtimer_expire_entry: hrtimer=000000002eda5fab function=tick_sched_timer now=604176096300 user_loop-273 [001] d.s2 604.184897: workqueue_queue_work: work struct=00000000383402c2 function=vmstat_update workqueue=00000000f36d35d4 req_cpu=1 cpu=1 user_loop-273 [001] dns2 604.185039: tick_stop: success=0 dependency=SCHED user_loop-273 [001] dn.1 604.185103: tick_stop: success=0 dependency=SCHED user_loop-273 [001] d..2 604.185154: sched_switch: prev_comm=taskset prev_pid=273 prev_prio=120 prev_state=R+ ==> next_comm=kworker/1:1 next_pid=46 next_prio=120 <...>-46 [001] .... 604.185194: workqueue_execute_start: work struct 00000000383402c2: function vmstat_update <...>-46 [001] d..2 604.185266: sched_switch: prev_comm=kworker/1:1 prev_pid=46 prev_prio=120 prev_state=I ==> next_comm=taskset next_pid=273 next_prio=120 user_loop-273 [001] d.h1 604.188812: hrtimer_expire_entry: hrtimer=000000002eda5fab function=tick_sched_timer now=604180133400 user_loop-273 [001] d..1 604.189050: tick_stop: success=1 dependency=NONE user_loop-273 [001] d..2 614.251386: sched_switch: prev_comm=user_loop prev_pid=273 prev_prio=120 prev_state=X ==> next_comm=swapper/1 next_pid=0 next_prio=120 <idle>-0 [001] d..2 614.315391: sched_switch: prev_comm=swapper/1 prev_pid=0 prev_prio=120 prev_state=R ==> next_comm=taskset next_pid=276 next_prio=120 Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>		2020-07-30 11:37:34 -07:00
..
boot	riscv: K210: Add a built-in device tree	2020-05-18 11:38:06 -07:00
configs	riscv: K210: Update defconfig	2020-05-18 11:38:07 -07:00
include	riscv: Support irq_work via self IPIs	2020-07-30 11:37:33 -07:00
kernel	riscv: Enable context tracking	2020-07-30 11:37:34 -07:00
lib	RISC-V Patches for the 5.7 Merge Window, Part 1	2020-04-09 10:51:30 -07:00
mm	riscv: Register System RAM as iomem resources	2020-07-09 12:42:02 -07:00
net	bpf, riscv: Optimize BPF_JSET BPF_K using andi on RV64	2020-05-06 09:48:15 +02:00
Kbuild	riscv: Allow device trees to be built into the kernel	2020-05-18 11:38:05 -07:00
Kconfig	riscv: Enable context tracking	2020-07-30 11:37:34 -07:00
Kconfig.debug
Kconfig.socs	riscv: K210: Add a built-in device tree	2020-05-18 11:38:06 -07:00
Makefile	RISC-V Patches for the 5.7 Merge Window, Part 1	2020-04-09 10:51:30 -07:00