| Message ID | 20250117101457.1530653-3-zhenglifeng1@huawei.com (mailing list archive) |
|---|---|
| State | In Next |
| Delegated to: | Rafael Wysocki |
| Headers | show |
| Series | cpufreq: Fix some boost errors related to CPU online and offline. | expand |
On 17-01-25, 18:14, Lifeng Zheng wrote: > In cpufreq_online() of cpufreq.c, the per-policy boost flag is already set > to mirror the cpufreq_driver boost during init but using freq_table to > judge if the policy has boost frequency. There are two drawbacks to this > approach: > > 1. It doesn't work for the cpufreq drivers that do not use a frequency > table. For now, acpi-cpufreq and amd-pstate have to enable boost in policy > initialization. And cppc_cpufreq never set policy to boost when going > online no matter what the cpufreq_driver boost flag is. > > 2. If the cpu goes offline when cpufreq_driver boost enabled and then goes > online when cpufreq_driver boost disabled, the per-policy boost flag will > unreasonably remain true. > > Running set_boost at the end of the online process is a more generic way > for all cpufreq drivers. > > Signed-off-by: Lifeng Zheng <zhenglifeng1@huawei.com> > --- > drivers/cpufreq/cpufreq.c | 16 ++++++++++++---- > 1 file changed, 12 insertions(+), 4 deletions(-) > > diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c > index 5882d7f5e3c1..5a3566c2eb8d 100644 > --- a/drivers/cpufreq/cpufreq.c > +++ b/drivers/cpufreq/cpufreq.c > @@ -1409,10 +1409,6 @@ static int cpufreq_online(unsigned int cpu) > goto out_free_policy; > } > > - /* Let the per-policy boost flag mirror the cpufreq_driver boost during init */ > - if (cpufreq_boost_enabled() && policy_has_boost_freq(policy)) > - policy->boost_enabled = true; > - > /* > * The initialization has succeeded and the policy is online. > * If there is a problem with its frequency table, take it > @@ -1573,6 +1569,18 @@ static int cpufreq_online(unsigned int cpu) > if (new_policy && cpufreq_thermal_control_enabled(cpufreq_driver)) > policy->cdev = of_cpufreq_cooling_register(policy); > > + /* Let the per-policy boost flag mirror the cpufreq_driver boost during init */ > + if (policy->boost_enabled != cpufreq_boost_enabled()) { > + policy->boost_enabled = cpufreq_boost_enabled(); > + ret = cpufreq_driver->set_boost(policy, policy->boost_enabled); I though you agreed to do some optimization here ? > + if (ret) { > + /* If the set_boost fails, the online operation is not affected */ > + pr_info("%s: CPU%d: Cannot %s BOOST\n", __func__, policy->cpu, > + policy->boost_enabled ? "enable" : "disable"); > + policy->boost_enabled = !policy->boost_enabled; > + } > + } > + > pr_debug("initialization complete\n"); > > return 0; > -- > 2.33.0
On 2025/1/20 17:01, Viresh Kumar wrote: > On 17-01-25, 18:14, Lifeng Zheng wrote: >> In cpufreq_online() of cpufreq.c, the per-policy boost flag is already set >> to mirror the cpufreq_driver boost during init but using freq_table to >> judge if the policy has boost frequency. There are two drawbacks to this >> approach: >> >> 1. It doesn't work for the cpufreq drivers that do not use a frequency >> table. For now, acpi-cpufreq and amd-pstate have to enable boost in policy >> initialization. And cppc_cpufreq never set policy to boost when going >> online no matter what the cpufreq_driver boost flag is. >> >> 2. If the cpu goes offline when cpufreq_driver boost enabled and then goes >> online when cpufreq_driver boost disabled, the per-policy boost flag will >> unreasonably remain true. >> >> Running set_boost at the end of the online process is a more generic way >> for all cpufreq drivers. >> >> Signed-off-by: Lifeng Zheng <zhenglifeng1@huawei.com> >> --- >> drivers/cpufreq/cpufreq.c | 16 ++++++++++++---- >> 1 file changed, 12 insertions(+), 4 deletions(-) >> >> diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c >> index 5882d7f5e3c1..5a3566c2eb8d 100644 >> --- a/drivers/cpufreq/cpufreq.c >> +++ b/drivers/cpufreq/cpufreq.c >> @@ -1409,10 +1409,6 @@ static int cpufreq_online(unsigned int cpu) >> goto out_free_policy; >> } >> >> - /* Let the per-policy boost flag mirror the cpufreq_driver boost during init */ >> - if (cpufreq_boost_enabled() && policy_has_boost_freq(policy)) >> - policy->boost_enabled = true; >> - >> /* >> * The initialization has succeeded and the policy is online. >> * If there is a problem with its frequency table, take it >> @@ -1573,6 +1569,18 @@ static int cpufreq_online(unsigned int cpu) >> if (new_policy && cpufreq_thermal_control_enabled(cpufreq_driver)) >> policy->cdev = of_cpufreq_cooling_register(policy); >> >> + /* Let the per-policy boost flag mirror the cpufreq_driver boost during init */ >> + if (policy->boost_enabled != cpufreq_boost_enabled()) { >> + policy->boost_enabled = cpufreq_boost_enabled(); >> + ret = cpufreq_driver->set_boost(policy, policy->boost_enabled); > > I though you agreed to do some optimization here ? Sorry. Do I miss something here? > >> + if (ret) { >> + /* If the set_boost fails, the online operation is not affected */ >> + pr_info("%s: CPU%d: Cannot %s BOOST\n", __func__, policy->cpu, >> + policy->boost_enabled ? "enable" : "disable"); >> + policy->boost_enabled = !policy->boost_enabled; >> + } >> + } >> + >> pr_debug("initialization complete\n"); >> >> return 0; >> -- >> 2.33.0 >
On 21-01-25, 09:45, zhenglifeng (A) wrote: > On 2025/1/20 17:01, Viresh Kumar wrote: > > On 17-01-25, 18:14, Lifeng Zheng wrote: > >> + /* Let the per-policy boost flag mirror the cpufreq_driver boost during init */ > >> + if (policy->boost_enabled != cpufreq_boost_enabled()) { > >> + policy->boost_enabled = cpufreq_boost_enabled(); > >> + ret = cpufreq_driver->set_boost(policy, policy->boost_enabled); > > > > I though you agreed to do some optimization here ? > > Sorry. Do I miss something here? https://lore.kernel.org/all/17c7ed77-21f1-4093-91fc-f3eaa863d312@huawei.com/
On 2025/1/21 12:20, Viresh Kumar wrote: > On 21-01-25, 09:45, zhenglifeng (A) wrote: >> On 2025/1/20 17:01, Viresh Kumar wrote: >>> On 17-01-25, 18:14, Lifeng Zheng wrote: >>>> + /* Let the per-policy boost flag mirror the cpufreq_driver boost during init */ >>>> + if (policy->boost_enabled != cpufreq_boost_enabled()) { >>>> + policy->boost_enabled = cpufreq_boost_enabled(); >>>> + ret = cpufreq_driver->set_boost(policy, policy->boost_enabled); >>> >>> I though you agreed to do some optimization here ? >> >> Sorry. Do I miss something here? > > https://lore.kernel.org/all/17c7ed77-21f1-4093-91fc-f3eaa863d312@huawei.com/ > I think I already done that, isn't it?
On 21-01-25, 14:22, zhenglifeng (A) wrote: > On 2025/1/21 12:20, Viresh Kumar wrote: > > > On 21-01-25, 09:45, zhenglifeng (A) wrote: > >> On 2025/1/20 17:01, Viresh Kumar wrote: > >>> On 17-01-25, 18:14, Lifeng Zheng wrote: > >>>> + /* Let the per-policy boost flag mirror the cpufreq_driver boost during init */ > >>>> + if (policy->boost_enabled != cpufreq_boost_enabled()) { > >>>> + policy->boost_enabled = cpufreq_boost_enabled(); > >>>> + ret = cpufreq_driver->set_boost(policy, policy->boost_enabled); > >>> > >>> I though you agreed to do some optimization here ? > >> > >> Sorry. Do I miss something here? > > > > https://lore.kernel.org/all/17c7ed77-21f1-4093-91fc-f3eaa863d312@huawei.com/ > > > > I think I already done that, isn't it? And I misread /facepalm .
On Fri, 2025-01-17 at 18:14 +0800, Lifeng Zheng wrote: > In cpufreq_online() of cpufreq.c, the per-policy boost flag is already set > to mirror the cpufreq_driver boost during init but using freq_table to > judge if the policy has boost frequency. There are two drawbacks to this > approach: > > 1. It doesn't work for the cpufreq drivers that do not use a frequency > table. For now, acpi-cpufreq and amd-pstate have to enable boost in policy > initialization. And cppc_cpufreq never set policy to boost when going > online no matter what the cpufreq_driver boost flag is. > > 2. If the cpu goes offline when cpufreq_driver boost enabled and then goes > online when cpufreq_driver boost disabled, the per-policy boost flag will > unreasonably remain true. > > Running set_boost at the end of the online process is a more generic way > for all cpufreq drivers. > > Signed-off-by: Lifeng Zheng <zhenglifeng1@huawei.com> > --- > drivers/cpufreq/cpufreq.c | 16 ++++++++++++---- > 1 file changed, 12 insertions(+), 4 deletions(-) > > diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c > index 5882d7f5e3c1..5a3566c2eb8d 100644 > --- a/drivers/cpufreq/cpufreq.c > +++ b/drivers/cpufreq/cpufreq.c > @@ -1409,10 +1409,6 @@ static int cpufreq_online(unsigned int cpu) > goto out_free_policy; > } > > - /* Let the per-policy boost flag mirror the cpufreq_driver boost during init */ > - if (cpufreq_boost_enabled() && policy_has_boost_freq(policy)) > - policy->boost_enabled = true; > - > /* > * The initialization has succeeded and the policy is online. > * If there is a problem with its frequency table, take it > @@ -1573,6 +1569,18 @@ static int cpufreq_online(unsigned int cpu) > if (new_policy && cpufreq_thermal_control_enabled(cpufreq_driver)) > policy->cdev = of_cpufreq_cooling_register(policy); > > + /* Let the per-policy boost flag mirror the cpufreq_driver boost during init */ > + if (policy->boost_enabled != cpufreq_boost_enabled()) { > + policy->boost_enabled = cpufreq_boost_enabled(); > + ret = cpufreq_driver->set_boost(policy, policy->boost_enabled); > + if (ret) { > + /* If the set_boost fails, the online operation is not affected */ > + pr_info("%s: CPU%d: Cannot %s BOOST\n", __func__, policy->cpu, > + policy->boost_enabled ? "enable" : "disable"); > + policy->boost_enabled = !policy->boost_enabled; > + } > + } > + > pr_debug("initialization complete\n"); > > > return 0; Hi, This patch causes a boot-time crash on PowerNV (Power9-baremetal systems) when WoF (Workload Optimized Frequency - boost) is enabled, starting from v6.14-rc1. The crash happens due to null pointer dereference of the `set_boost` function. `set_boost` is only assigned after the cpufreq driver is registered on PowerNV as below, Initialization Flow: (powernv_cpufreq_init -> cpufreq_enable_boost_support -> initializes set_boost). However, with this patch, `set_boost` is invoked in `cpufreq_register_driver` before it is initialized. Access Flow: (powernv_cpufreq_init -> cpufreq_register_driver -> cpufreq_online -> attempts to access cpufreq_driver->set_boost, which is still NULL at this point). This causes a boot-time crash as follows: [ 9.393946][ T1] BUG: Unable to handle kernel instruction fetch (NULL pointer?) [ 9.393946][ T1] BUG: Unable to handle kernel instruction fetch (NULL pointer?) [ 9.396285][ T1] Faulting instruction address: 0x00000000 [ 9.396285][ T1] Faulting instruction address: 0x00000000 [ 9.398545][ T1] Oops: Kernel access of bad area, sig: 7 [#1] [ 9.398545][ T1] Oops: Kernel access of bad area, sig: 7 [#1] [ 9.398804][ T1] LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA PowerNV [ 9.398804][ T1] LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA PowerNV [ 9.400114][ T1] Modules linked in: [ 9.400114][ T1] Modules linked in: [ 9.400283][ T1] CPU: 19 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.14.0-rc1-dirty #23 [ 9.400283][ T1] CPU: 19 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.14.0-rc1-dirty #23 [ 9.400605][ T1] Hardware name: 0000000000000000 POWER9 0x4e1202 opal:v6.6-111-gd362ae4f-root-dirty-157d5e1 PowerNV [ 9.400605][ T1] Hardware name: 0000000000000000 POWER9 0x4e1202 opal:v6.6-111-gd362ae4f-root-dirty-157d5e1 PowerNV [ 9.403093][ T1] NIP: 0000000000000000 LR: c000000000f7a574 CTR: 0000000000000000 [ 9.403093][ T1] NIP: 0000000000000000 LR: c000000000f7a574 CTR: 0000000000000000 [ 9.404397][ T1] REGS: c00020000419f680 TRAP: 0400 Not tainted (6.14.0-rc1-dirty) [ 9.404397][ T1] REGS: c00020000419f680 TRAP: 0400 Not tainted (6.14.0-rc1-dirty) [ 9.407771][ T1] MSR: 9000000002089033 <SF,HV,VEC,EE,ME,IR,DR,RI,LE> CR: 84000482 XER: 00000000 [ 9.407771][ T1] MSR: 9000000002089033 <SF,HV,VEC,EE,ME,IR,DR,RI,LE> CR: 84000482 XER: 00000000 [ 9.409191][ T1] CFAR: c000000000f7a570 IRQMASK: 0 [ 9.409191][ T1] GPR00: c000000000f7a51c c00020000419f920 c000000001ea3200 c00020002455f800 [ 9.409191][ T1] GPR04: 0000000000000001 0000000000000000 0000000000000001 0000000000000000 [ 9.409191][ T1] GPR08: 0000000000000000 c000000002a1f280 0000000000000001 0000000000000000 [ 9.409191][ T1] GPR12: 0000000000000000 c000003ffefe0900 c00000000001101c 0000000000000000 [ 9.409191][ T1] GPR16: 0000000000000000 0000000000000000 c000000002c20b80 000000000000005a [ 9.409191][ T1] GPR20: c00000007ffa0a14 c000000002973200 c000000002c1ff38 c00020002455fc48 [ 9.409191][ T1] GPR24: c0000000029752f8 c000000002c1ff10 c00020002455fcb8 0000000000000000 [ 9.409191][ T1] GPR28: c000000002a71be0 0000000000000000 c00020002455f800 c000000002a1f0a0 [ 9.409191][ T1] CFAR: c000000000f7a570 IRQMASK: 0 [ 9.409191][ T1] GPR00: c000000000f7a51c c00020000419f920 c000000001ea3200 c00020002455f800 [ 9.409191][ T1] GPR04: 0000000000000001 0000000000000000 0000000000000001 0000000000000000 [ 9.409191][ T1] GPR08: 0000000000000000 c000000002a1f280 0000000000000001 0000000000000000 [ 9.409191][ T1] GPR12: 0000000000000000 c000003ffefe0900 c00000000001101c 0000000000000000 [ 9.409191][ T1] GPR16: 0000000000000000 0000000000000000 c000000002c20b80 000000000000005a [ 9.409191][ T1] GPR20: c00000007ffa0a14 c000000002973200 c000000002c1ff38 c00020002455fc48 [ 9.409191][ T1] GPR24: c0000000029752f8 c000000002c1ff10 c00020002455fcb8 0000000000000000 [ 9.409191][ T1] GPR28: c000000002a71be0 0000000000000000 c00020002455f800 c000000002a1f0a0 [ 9.415226][ T1] NIP [0000000000000000] 0x0 [ 9.415226][ T1] NIP [0000000000000000] 0x0 [ 9.417435][ T1] LR [c000000000f7a574] cpufreq_online+0x440/0xe14 [ 9.417435][ T1] LR [c000000000f7a574] cpufreq_online+0x440/0xe14 [ 9.419701][ T1] Call Trace: [ 9.419701][ T1] Call Trace: [ 9.422849][ T1] [c00020000419f920] [c000000000f7a51c] cpufreq_online+0x3e8/0xe14 (unreliable) [ 9.422849][ T1] [c00020000419f920] [c000000000f7a51c] cpufreq_online+0x3e8/0xe14 (unreliable) [ 9.430225][ T1] [c00020000419fa00] [c000000000f7b030] cpufreq_add_dev+0xb4/0xd8 [ 9.430225][ T1] [c00020000419fa00] [c000000000f7b030] cpufreq_add_dev+0xb4/0xd8 [ 9.434547][ T1] [c00020000419fa30] [c000000000c89e18] subsys_interface_register+0x18c/0x1d4 [ 9.434547][ T1] [c00020000419fa30] [c000000000c89e18] subsys_interface_register+0x18c/0x1d4 [ 9.440934][ T1] [c00020000419faa0] [c000000000f763a8] cpufreq_register_driver+0x1f0/0x370 [ 9.440934][ T1] [c00020000419faa0] [c000000000f763a8] cpufreq_register_driver+0x1f0/0x370 [ 9.444314][ T1] [c00020000419fb20] [c000000002093340] powernv_cpufreq_init+0x690/0xa10 [ 9.444314][ T1] [c00020000419fb20] [c000000002093340] powernv_cpufreq_init+0x690/0xa10 [ 9.444686][ T1] [c00020000419fc30] [c000000000010cb8] do_one_initcall+0x60/0x2c8 [ 9.444686][ T1] [c00020000419fc30] [c000000000010cb8] do_one_initcall+0x60/0x2c8 [ 9.445024][ T1] [c00020000419fd00] [c0000000020059ec] kernel_init_freeable+0x33c/0x530 [ 9.445024][ T1] [c00020000419fd00] [c0000000020059ec] kernel_init_freeable+0x33c/0x530 [ 9.446375][ T1] [c00020000419fde0] [c000000000011048] kernel_init+0x34/0x26c [ 9.446375][ T1] [c00020000419fde0] [c000000000011048] kernel_init+0x34/0x26c [ 9.448684][ T1] [c00020000419fe50] [c00000000000debc] ret_from_kernel_user_thread+0x14/0x1c [ 9.448684][ T1] [c00020000419fe50] [c00000000000debc] ret_from_kernel_user_thread+0x14/0x1c [ 9.455840][ T1] ---[ end trace 0000000000000000 ]--- [ 9.455840][ T1] ---[ end trace 0000000000000000 ]--- The fix will be to initialize set_boost earlier in powernv_cpufreq_init before calling cpufreq_register_driver. Quickly tried this patch and it resolves the issue: --- diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c index ae79d909943b..2dd61de34a28 100644 --- a/drivers/cpufreq/powernv-cpufreq.c +++ b/drivers/cpufreq/powernv-cpufreq.c @@ -1127,8 +1127,10 @@ static int __init powernv_cpufreq_init(void) if (rc) goto out; - if (powernv_pstate_info.wof_enabled) + if (powernv_pstate_info.wof_enabled) { powernv_cpufreq_driver.boost_enabled = true; + powernv_cpufreq_driver.set_boost = cpufreq_boost_set_sw; + } else powernv_cpu_freq_attr[SCALING_BOOST_FREQS_ATTR_INDEX] = NULL; @@ -1138,9 +1140,6 @@ static int __init powernv_cpufreq_init(void) goto cleanup; } - if (powernv_pstate_info.wof_enabled) - cpufreq_enable_boost_support(); - register_reboot_notifier(&powernv_cpufreq_reboot_nb); opal_message_notifier_register(OPAL_MSG_OCC, &powernv_cpufreq_opal_nb); --- I noticed that Viresh is working on a similar patch [1] as part of a broader patchset to simplify boost handling, which should also resolve this issue. Should we merge this patch [1] and related patches since this is causing a crash, or submit a separate patch to fix this? [1]: https://lore.kernel.org/all/9b4af20d5b415f41e866ddd8bde9cf6441c463b8.1737707712.git.viresh.kumar@linaro.org/ Regards, Aboorva
On 04-02-25, 22:11, Aboorva Devarajan wrote: > I noticed that Viresh is working on a similar patch [1] as part of a broader patchset > to simplify boost handling, which should also resolve this issue. > > Should we merge this patch [1] and related patches since this is causing a crash, > or submit a separate patch to fix this? diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index d434096b7515..7c1f7f5142da 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -1590,7 +1590,8 @@ static int cpufreq_online(unsigned int cpu) policy->cdev = of_cpufreq_cooling_register(policy); /* Let the per-policy boost flag mirror the cpufreq_driver boost during init */ - if (policy->boost_enabled != cpufreq_boost_enabled()) { + if (cpufreq_driver->set_boost && + policy->boost_enabled != cpufreq_boost_enabled()) { policy->boost_enabled = cpufreq_boost_enabled(); ret = cpufreq_driver->set_boost(policy, policy->boost_enabled); if (ret) { I think the right fix for now should be something like this. My series (which will be part of next merge window) can go in separately and revert this change then (as we won't see this problem then). Please send a fix with something like this if it works fine, so Rafael can apply.
On Wed, 2025-02-05 at 10:31 +0530, Viresh Kumar wrote: > On 04-02-25, 22:11, Aboorva Devarajan wrote: > > I noticed that Viresh is working on a similar patch [1] as part of a broader patchset > > to simplify boost handling, which should also resolve this issue. > > > > Should we merge this patch [1] and related patches since this is causing a crash, > > or submit a separate patch to fix this? > > diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c > index d434096b7515..7c1f7f5142da 100644 > --- a/drivers/cpufreq/cpufreq.c > +++ b/drivers/cpufreq/cpufreq.c > @@ -1590,7 +1590,8 @@ static int cpufreq_online(unsigned int cpu) > policy->cdev = of_cpufreq_cooling_register(policy); > > /* Let the per-policy boost flag mirror the cpufreq_driver boost during init */ > - if (policy->boost_enabled != cpufreq_boost_enabled()) { > + if (cpufreq_driver->set_boost && > + policy->boost_enabled != cpufreq_boost_enabled()) { > policy->boost_enabled = cpufreq_boost_enabled(); > ret = cpufreq_driver->set_boost(policy, policy->boost_enabled); > if (ret) { > > I think the right fix for now should be something like this. My series > (which will be part of next merge window) can go in separately and > revert this change then (as we won't see this problem then). > > Please send a fix with something like this if it works fine, so Rafael > can apply. > Hi Viresh, Thanks, I have posted a patch for this: https://lore.kernel.org/all/20250205181347.2079272-1-aboorvad@linux.ibm.com/ this should get past the boot-time crash for now, until your patchset to simplify boost handling is merged. Regards, Aboorva
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 5882d7f5e3c1..5a3566c2eb8d 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -1409,10 +1409,6 @@ static int cpufreq_online(unsigned int cpu) goto out_free_policy; } - /* Let the per-policy boost flag mirror the cpufreq_driver boost during init */ - if (cpufreq_boost_enabled() && policy_has_boost_freq(policy)) - policy->boost_enabled = true; - /* * The initialization has succeeded and the policy is online. * If there is a problem with its frequency table, take it @@ -1573,6 +1569,18 @@ static int cpufreq_online(unsigned int cpu) if (new_policy && cpufreq_thermal_control_enabled(cpufreq_driver)) policy->cdev = of_cpufreq_cooling_register(policy); + /* Let the per-policy boost flag mirror the cpufreq_driver boost during init */ + if (policy->boost_enabled != cpufreq_boost_enabled()) { + policy->boost_enabled = cpufreq_boost_enabled(); + ret = cpufreq_driver->set_boost(policy, policy->boost_enabled); + if (ret) { + /* If the set_boost fails, the online operation is not affected */ + pr_info("%s: CPU%d: Cannot %s BOOST\n", __func__, policy->cpu, + policy->boost_enabled ? "enable" : "disable"); + policy->boost_enabled = !policy->boost_enabled; + } + } + pr_debug("initialization complete\n"); return 0;
In cpufreq_online() of cpufreq.c, the per-policy boost flag is already set to mirror the cpufreq_driver boost during init but using freq_table to judge if the policy has boost frequency. There are two drawbacks to this approach: 1. It doesn't work for the cpufreq drivers that do not use a frequency table. For now, acpi-cpufreq and amd-pstate have to enable boost in policy initialization. And cppc_cpufreq never set policy to boost when going online no matter what the cpufreq_driver boost flag is. 2. If the cpu goes offline when cpufreq_driver boost enabled and then goes online when cpufreq_driver boost disabled, the per-policy boost flag will unreasonably remain true. Running set_boost at the end of the online process is a more generic way for all cpufreq drivers. Signed-off-by: Lifeng Zheng <zhenglifeng1@huawei.com> --- drivers/cpufreq/cpufreq.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-)