From f0c7183008b41e92fa676406d87f18773724b48b Mon Sep 17 00:00:00 2001 From: Brian Geffon Date: Thu, 21 Sep 2023 13:00:45 -0400 Subject: PM: hibernate: Use __get_safe_page() rather than touching the list We found at least one situation where the safe pages list was empty and get_buffer() would gladly try to use a NULL pointer. Signed-off-by: Brian Geffon Fixes: 8357376d3df2 ("[PATCH] swsusp: Improve handling of highmem") Cc: All applicable Signed-off-by: Rafael J. Wysocki --- kernel/power/snapshot.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) (limited to 'kernel') diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index 87e9f7e2bdc0..acd2e49b9ac8 100644 --- a/kernel/power/snapshot.c +++ b/kernel/power/snapshot.c @@ -2545,8 +2545,9 @@ static void *get_highmem_page_buffer(struct page *page, pbe->copy_page = tmp; } else { /* Copy of the page will be stored in normal memory */ - kaddr = safe_pages_list; - safe_pages_list = safe_pages_list->next; + kaddr = __get_safe_page(ca->gfp_mask); + if (!kaddr) + return ERR_PTR(-ENOMEM); pbe->copy_page = virt_to_page(kaddr); } pbe->next = highmem_pblist; @@ -2750,8 +2751,9 @@ static void *get_buffer(struct memory_bitmap *bm, struct chain_allocator *ca) return ERR_PTR(-ENOMEM); } pbe->orig_address = page_address(page); - pbe->address = safe_pages_list; - safe_pages_list = safe_pages_list->next; + pbe->address = __get_safe_page(ca->gfp_mask); + if (!pbe->address) + return ERR_PTR(-ENOMEM); pbe->next = restore_pblist; restore_pblist = pbe; return pbe->address; -- cgit v1.2.3 From d08970df1980476f27936e24d452550f3e9e92e1 Mon Sep 17 00:00:00 2001 From: Brian Geffon Date: Fri, 22 Sep 2023 12:07:04 -0400 Subject: PM: hibernate: Clean up sync_read handling in snapshot_write_next() In snapshot_write_next(), sync_read is set and unset in three different spots unnecessiarly. As a result there is a subtle bug where the first page after the meta data has been loaded unconditionally sets sync_read to 0. If this first PFN was actually a highmem page, then the returned buffer will be the global "buffer," and the page needs to be loaded synchronously. That is, I'm not sure we can always assume the following to be safe: handle->buffer = get_buffer(&orig_bm, &ca); handle->sync_read = 0; Because get_buffer() can call get_highmem_page_buffer() which can return 'buffer'. The easiest way to address this is just set sync_read before snapshot_write_next() returns if handle->buffer == buffer. Signed-off-by: Brian Geffon Fixes: 8357376d3df2 ("[PATCH] swsusp: Improve handling of highmem") Cc: All applicable [ rjw: Subject and changelog edits ] Signed-off-by: Rafael J. Wysocki --- kernel/power/snapshot.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) (limited to 'kernel') diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index acd2e49b9ac8..7f0e6870318b 100644 --- a/kernel/power/snapshot.c +++ b/kernel/power/snapshot.c @@ -2785,8 +2785,6 @@ next: if (handle->cur > 1 && handle->cur > nr_meta_pages + nr_copy_pages + nr_zero_pages) return 0; - handle->sync_read = 1; - if (!handle->cur) { if (!buffer) /* This makes the buffer be freed by swsusp_free() */ @@ -2829,7 +2827,6 @@ next: memory_bm_position_reset(&zero_bm); restore_pblist = NULL; handle->buffer = get_buffer(&orig_bm, &ca); - handle->sync_read = 0; if (IS_ERR(handle->buffer)) return PTR_ERR(handle->buffer); } @@ -2839,9 +2836,8 @@ next: handle->buffer = get_buffer(&orig_bm, &ca); if (IS_ERR(handle->buffer)) return PTR_ERR(handle->buffer); - if (handle->buffer != buffer) - handle->sync_read = 0; } + handle->sync_read = (handle->buffer == buffer); handle->cur++; /* Zero pages were not included in the image, memset it and move on. */ -- cgit v1.2.3 From 7bf770f74e850c0b8d21ac143b3b2bc18813a6eb Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 25 Sep 2023 09:40:58 +0200 Subject: PM: hibernate: fix the kerneldoc comment for swsusp_check() and swsusp_close() The comments for both swsusp_check() and swsusp_close() don't actually describe what they are doing. Just removing the comments would probably better, but as the file is full of useless kerneldoc comments for non-exported symbols this fits in better with the style. Signed-off-by: Christoph Hellwig Signed-off-by: Rafael J. Wysocki --- kernel/power/swap.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/power/swap.c b/kernel/power/swap.c index 74edbce2320b..a64af0a552f9 100644 --- a/kernel/power/swap.c +++ b/kernel/power/swap.c @@ -1513,7 +1513,7 @@ end: static void *swsusp_holder; /** - * swsusp_check - Check for swsusp signature in the resume device + * swsusp_check - Open the resume device and check for the swsusp signature. * @exclusive: Open the resume device exclusively. */ @@ -1564,7 +1564,7 @@ put: } /** - * swsusp_close - close swap device. + * swsusp_close - close resume device. * @exclusive: Close the resume device which is exclusively opened. */ -- cgit v1.2.3 From 16a03c71bba012b4cc31f34e00007c34ef5a58df Mon Sep 17 00:00:00 2001 From: Liao Chang Date: Fri, 8 Sep 2023 03:16:04 +0000 Subject: cpufreq: schedutil: Merge initialization code of sg_cpu in single loop The initialization code of the per-cpu sg_cpu struct is currently split into two for-loop blocks. This can be simplified by merging the two blocks into a single loop. This will make the code more maintainable. Signed-off-by: Liao Chang Acked-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki --- kernel/sched/cpufreq_schedutil.c | 11 +++-------- 1 file changed, 3 insertions(+), 8 deletions(-) (limited to 'kernel') diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c index 4492608b7d7f..f3a95def49cc 100644 --- a/kernel/sched/cpufreq_schedutil.c +++ b/kernel/sched/cpufreq_schedutil.c @@ -767,14 +767,6 @@ static int sugov_start(struct cpufreq_policy *policy) sg_policy->need_freq_update = cpufreq_driver_test_flags(CPUFREQ_NEED_UPDATE_LIMITS); - for_each_cpu(cpu, policy->cpus) { - struct sugov_cpu *sg_cpu = &per_cpu(sugov_cpu, cpu); - - memset(sg_cpu, 0, sizeof(*sg_cpu)); - sg_cpu->cpu = cpu; - sg_cpu->sg_policy = sg_policy; - } - if (policy_is_shared(policy)) uu = sugov_update_shared; else if (policy->fast_switch_enabled && cpufreq_driver_has_adjust_perf()) @@ -785,6 +777,9 @@ static int sugov_start(struct cpufreq_policy *policy) for_each_cpu(cpu, policy->cpus) { struct sugov_cpu *sg_cpu = &per_cpu(sugov_cpu, cpu); + memset(sg_cpu, 0, sizeof(*sg_cpu)); + sg_cpu->cpu = cpu; + sg_cpu->sg_policy = sg_policy; cpufreq_add_update_util_hook(cpu, &sg_cpu->update_util, uu); } return 0; -- cgit v1.2.3 From e7a1b32e43b194bbf930281ae7f5149c420cd122 Mon Sep 17 00:00:00 2001 From: Pierre Gondois Date: Thu, 5 Oct 2023 15:41:20 +0200 Subject: cpufreq: Rebuild sched-domains when removing cpufreq driver The Energy Aware Scheduler (EAS) relies on the schedutil governor. When moving to/from the schedutil governor, sched domains must be rebuilt to allow re-evaluating the enablement conditions of EAS. This is done through sched_cpufreq_governor_change(). Having a cpufreq governor assumes a cpufreq driver is running. Inserting/removing a cpufreq driver should trigger a re-evaluation of EAS enablement conditions, avoiding to see EAS enabled when removing a running cpufreq driver. Rebuild the sched domains in schedutil's sugov_init()/sugov_exit(), allowing to check EAS's enablement condition whenever schedutil governor is initialized/exited from. Move relevant code up in schedutil.c to avoid a split and conditional function declaration. Rename sched_cpufreq_governor_change() to sugov_eas_rebuild_sd(). Signed-off-by: Pierre Gondois Acked-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki --- kernel/sched/cpufreq_schedutil.c | 55 +++++++++++++++++++++------------------- 1 file changed, 29 insertions(+), 26 deletions(-) (limited to 'kernel') diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c index f3a95def49cc..492ec650d48f 100644 --- a/kernel/sched/cpufreq_schedutil.c +++ b/kernel/sched/cpufreq_schedutil.c @@ -555,6 +555,31 @@ static const struct kobj_type sugov_tunables_ktype = { /********************** cpufreq governor interface *********************/ +#ifdef CONFIG_ENERGY_MODEL +static void rebuild_sd_workfn(struct work_struct *work) +{ + rebuild_sched_domains_energy(); +} + +static DECLARE_WORK(rebuild_sd_work, rebuild_sd_workfn); + +/* + * EAS shouldn't be attempted without sugov, so rebuild the sched_domains + * on governor changes to make sure the scheduler knows about it. + */ +static void sugov_eas_rebuild_sd(void) +{ + /* + * When called from the cpufreq_register_driver() path, the + * cpu_hotplug_lock is already held, so use a work item to + * avoid nested locking in rebuild_sched_domains(). + */ + schedule_work(&rebuild_sd_work); +} +#else +static inline void sugov_eas_rebuild_sd(void) { }; +#endif + struct cpufreq_governor schedutil_gov; static struct sugov_policy *sugov_policy_alloc(struct cpufreq_policy *policy) @@ -709,6 +734,8 @@ static int sugov_init(struct cpufreq_policy *policy) if (ret) goto fail; + sugov_eas_rebuild_sd(); + out: mutex_unlock(&global_tunables_lock); return 0; @@ -750,6 +777,8 @@ static void sugov_exit(struct cpufreq_policy *policy) sugov_kthread_stop(sg_policy); sugov_policy_free(sg_policy); cpufreq_disable_fast_switch(policy); + + sugov_eas_rebuild_sd(); } static int sugov_start(struct cpufreq_policy *policy) @@ -833,29 +862,3 @@ struct cpufreq_governor *cpufreq_default_governor(void) #endif cpufreq_governor_init(schedutil_gov); - -#ifdef CONFIG_ENERGY_MODEL -static void rebuild_sd_workfn(struct work_struct *work) -{ - rebuild_sched_domains_energy(); -} -static DECLARE_WORK(rebuild_sd_work, rebuild_sd_workfn); - -/* - * EAS shouldn't be attempted without sugov, so rebuild the sched_domains - * on governor changes to make sure the scheduler knows about it. - */ -void sched_cpufreq_governor_change(struct cpufreq_policy *policy, - struct cpufreq_governor *old_gov) -{ - if (old_gov == &schedutil_gov || policy->governor == &schedutil_gov) { - /* - * When called from the cpufreq_register_driver() path, the - * cpu_hotplug_lock is already held, so use a work item to - * avoid nested locking in rebuild_sched_domains(). - */ - schedule_work(&rebuild_sd_work); - } - -} -#endif -- cgit v1.2.3