lwn.git/drivers/cpufreq/cpufreq_governor.c, branch v6.5

cpufreq: governor: Use kobject release() method to free dbs_data

2022-04-13T13:22:41+00:00

The struct dbs_data embeds a struct gov_attr_set and the struct gov_attr_set embeds a kobject. Since every kobject must have a release() method and we can't use kfree() to free it directly, so introduce cpufreq_dbs_data_release() to release the dbs_data via the kobject::release() method. This fixes the calltrace like below: ODEBUG: free active (active state 0) object type: timer_list hint: delayed_work_timer_fn+0x0/0x34 WARNING: CPU: 12 PID: 810 at lib/debugobjects.c:505 debug_print_object+0xb8/0x100 Modules linked in: CPU: 12 PID: 810 Comm: sh Not tainted 5.16.0-next-20220120-yocto-standard+ #536 Hardware name: Marvell OcteonTX CN96XX board (DT) pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : debug_print_object+0xb8/0x100 lr : debug_print_object+0xb8/0x100 sp : ffff80001dfcf9a0 x29: ffff80001dfcf9a0 x28: 0000000000000001 x27: ffff0001464f0000 x26: 0000000000000000 x25: ffff8000090e3f00 x24: ffff80000af60210 x23: ffff8000094dfb78 x22: ffff8000090e3f00 x21: ffff0001080b7118 x20: ffff80000aeb2430 x19: ffff800009e8f5e0 x18: 0000000000000000 x17: 0000000000000002 x16: 00004d62e58be040 x15: 013590470523aff8 x14: ffff8000090e1828 x13: 0000000001359047 x12: 00000000f5257d14 x11: 0000000000040591 x10: 0000000066c1ffea x9 : ffff8000080d15e0 x8 : ffff80000a1765a8 x7 : 0000000000000000 x6 : 0000000000000001 x5 : ffff800009e8c000 x4 : ffff800009e8c760 x3 : 0000000000000000 x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff0001474ed040 Call trace: debug_print_object+0xb8/0x100 __debug_check_no_obj_freed+0x1d0/0x25c debug_check_no_obj_freed+0x24/0xa0 kfree+0x11c/0x440 cpufreq_dbs_governor_exit+0xa8/0xac cpufreq_exit_governor+0x44/0x90 cpufreq_set_policy+0x29c/0x570 store_scaling_governor+0x110/0x154 store+0xb0/0xe0 sysfs_kf_write+0x58/0x84 kernfs_fop_write_iter+0x12c/0x1c0 new_sync_write+0xf0/0x18c vfs_write+0x1cc/0x220 ksys_write+0x74/0x100 __arm64_sys_write+0x28/0x3c invoke_syscall.constprop.0+0x58/0xf0 do_el0_svc+0x70/0x170 el0_svc+0x54/0x190 el0t_64_sync_handler+0xa4/0x130 el0t_64_sync+0x1a0/0x1a4 irq event stamp: 189006 hardirqs last enabled at (189005): [] finish_task_switch.isra.0+0xe0/0x2c0 hardirqs last disabled at (189006): [] el1_dbg+0x24/0xa0 softirqs last enabled at (188966): [] __do_softirq+0x4b0/0x6a0 softirqs last disabled at (188957): [] __irq_exit_rcu+0x108/0x1a4 [ rjw: Because can be freed by the gov_attr_set_put() in cpufreq_dbs_governor_exit() now, it is also necessary to put the invocation of the governor ->exit() callback into the new cpufreq_dbs_data_release() function. ] Fixes: c4435630361d ("cpufreq: governor: New sysfs show/store callbacks for governor tunables") Signed-off-by: Kevin Hao Signed-off-by: Rafael J. Wysocki

cpufreq: unify show() and store() naming and use __ATTR_XX

2022-03-10T18:55:05+00:00

Usually, sysfs attributes have .show and .store and their naming convention is filename_show() and filename_store(). But in cpufreq the naming convention of these functions is show_filename() and store_filename() which prevents __ATTR_RW() and __ATTR_RO() from being used in there to simplify code. Accordingly, change the naming convention of the sysfs .show and .store methods in cpufreq to follow the one expected by __ATTR_RW() and __ATTR_RO() and use these macros in that code. Signed-off-by: Lianjie Zhang [ rjw: Subject and changelog edits ] Signed-off-by: Rafael J. Wysocki

cpufreq: cpufreq_governor: Demote store_sampling_rate() header to standard comment block

2020-07-15T13:17:06+00:00

There is no need for this to be denoted as kerneldoc. Fixes the following W=1 kernel build warning(s): drivers/cpufreq/cpufreq_governor.c:46: warning: Function parameter or member 'attr_set' not described in 'store_sampling_rate' drivers/cpufreq/cpufreq_governor.c:46: warning: Function parameter or member 'buf' not described in 'store_sampling_rate' drivers/cpufreq/cpufreq_governor.c:46: warning: Function parameter or member 'count' not described in 'store_sampling_rate' Signed-off-by: Lee Jones Acked-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki

cpufreq: Use vtime aware kcpustat accessors for user time

2019-11-21T06:33:25+00:00

We can now safely read user and guest kcpustat fields on nohz_full CPUs. Use the appropriate accessors. Reported-by: Yauheni Kaliuta Signed-off-by: Frederic Weisbecker Cc: Rafael J. Wysocki Cc: Viresh Kumar Cc: Peter Zijlstra Cc: Wanpeng Li Link: https://lkml.kernel.org/r/20191121024430.19938-5-frederic@kernel.org Signed-off-by: Ingo Molnar

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

2019-06-19T15:09:55+00:00

Based on 2 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Enrico Weigelt Reviewed-by: Kate Stewart Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman

cpufreq: Fix kobject memleak

2019-04-30T08:54:23+00:00

Currently the error return path from kobject_init_and_add() is not followed by a call to kobject_put() - which means we are leaking the kobject. Fix it by adding a call to kobject_put() in the error path of kobject_init_and_add(). Signed-off-by: Viresh Kumar Reviewed-by: Tobin C. Harding Signed-off-by: Rafael J. Wysocki

cpufreq/cpufreq_governor: Replace synchronize_sched() with synchronize_rcu()

2018-11-27T17:21:38+00:00

Now that synchronize_rcu() waits for preempt-disable regions of code as well as RCU read-side critical sections, synchronize_sched() can be replaced by synchronize_rcu(). This commit therefore makes this change. Signed-off-by: Paul E. McKenney

cpufreq: governor: Avoid accessing invalid governor_data

2018-08-16T21:03:29+00:00

If cppc_cpufreq.ko is deleted at the same time that tuned-adm is changing profiles, there is a small chance that a race can occur between cpufreq_dbs_governor_exit() and cpufreq_dbs_governor_limits() resulting in a system failure when the latter tries to use policy->governor_data that has been freed by the former. This patch uses gov_dbs_data_mutex to synchronize access. Fixes: e788892ba3cc (cpufreq: governor: Get rid of governor events) Signed-off-by: Henry Willard [ rjw: Subject, minor white space adjustment ] Cc: 4.8+ # 4.8+ Signed-off-by: Rafael J. Wysocki

cpufreq: governors: Fix long idle detection logic in load calculation

2018-06-08T09:40:44+00:00

According to current code implementation, detecting the long idle period is done by checking if the interval between two adjacent utilization update handlers is long enough. Although this mechanism can detect if the idle period is long enough (no utilization hooks invoked during idle period), it might not cover a corner case: if the task has occupied the CPU for too long which causes no context switches during that period, then no utilization handler will be launched until this high prio task is scheduled out. As a result, the idle_periods field might be calculated incorrectly because it regards the 100% load as 0% and makes the conservative governor who uses this field confusing. Change the detection to compare the idle_time with sampling_rate directly. Reported-by: Artem S. Tashkinov Signed-off-by: Chen Yu Acked-by: Viresh Kumar Cc: All applicable Signed-off-by: Rafael J. Wysocki

cpufreq: Rename cpufreq_can_do_remote_dvfs()

2018-05-23T08:37:08+00:00

This routine checks if the CPU running this code belongs to the policy of the target CPU or if not, can it do remote DVFS for it remotely. But the current name of it implies as if it is only about doing remote updates. Rename it to make it more relevant. Suggested-by: Rafael J. Wysocki Signed-off-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki