From f943849f720689214abb3930623c31ff91990be9 Mon Sep 17 00:00:00 2001 From: Sudeep Holla Date: Fri, 20 Nov 2020 10:12:52 +0000 Subject: [PATCH 1/2] cpufreq: scmi: Fix build for !CONFIG_COMMON_CLK Commit 8410e7f3b31e ("cpufreq: scmi: Fix OPP addition failure with a dummy clock provider") registers a dummy clock provider using devm_of_clk_add_hw_provider. These *_hw_provider functions are defined only when CONFIG_COMMON_CLK=y. One possible fix is to add the Kconfig dependency, but since we plan to move away from the clock dependency for scmi cpufreq, it is preferrable to avoid that. Let us just conditionally compile out the offending call to devm_of_clk_add_hw_provider. It also uses the variable 'dev' outside of the #ifdef block to avoid build warning. Fixes: 8410e7f3b31e ("cpufreq: scmi: Fix OPP addition failure with a dummy clock provider") Cc: Rafael J. Wysocki Cc: Viresh Kumar Signed-off-by: Sudeep Holla Signed-off-by: Viresh Kumar --- drivers/cpufreq/scmi-cpufreq.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/cpufreq/scmi-cpufreq.c b/drivers/cpufreq/scmi-cpufreq.c index 78318508a6d6..8286205c7165 100644 --- a/drivers/cpufreq/scmi-cpufreq.c +++ b/drivers/cpufreq/scmi-cpufreq.c @@ -236,13 +236,15 @@ static int scmi_cpufreq_probe(struct scmi_device *sdev) if (!handle || !handle->perf_ops) return -ENODEV; +#ifdef CONFIG_COMMON_CLK /* dummy clock provider as needed by OPP if clocks property is used */ if (of_find_property(dev->of_node, "#clock-cells", NULL)) devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get, NULL); +#endif ret = cpufreq_register_driver(&scmi_cpufreq_driver); if (ret) { - dev_err(&sdev->dev, "%s: registering cpufreq failed, err: %d\n", + dev_err(dev, "%s: registering cpufreq failed, err: %d\n", __func__, ret); } From 4df910620bebb5cfe234af16ac8f6474b60215fd Mon Sep 17 00:00:00 2001 From: Feng Tang Date: Wed, 25 Nov 2020 13:22:21 +0800 Subject: [PATCH 2/2] mm: memcg: relayout structure mem_cgroup to avoid cache interference 0day reported one -22.7% regression for will-it-scale page_fault2 case [1] on a 4 sockets 144 CPU platform, and bisected to it to be caused by Waiman's optimization (commit bd0b230fe1) of saving one 'struct page_counter' space for 'struct mem_cgroup'. Initially we thought it was due to the cache alignment change introduced by the patch, but further debug shows that it is due to some hot data members ('vmstats_local', 'vmstats_percpu', 'vmstats') sit in 2 adjacent cacheline (2N and 2N+1 cacheline), and when adjacent cache line prefetch is enabled, it triggers an "extended level" of cache false sharing for 2 adjacent cache lines. So exchange the 2 member blocks, while keeping mostly the original cache alignment, which can restore and even enhance the performance, and save 64 bytes of space for 'struct mem_cgroup' (from 2880 to 2816, with 0day's default RHEL-8.3 kernel config) [1]. https://lore.kernel.org/lkml/20201102091543.GM31092@shao2-debian/ Fixes: bd0b230fe145 ("mm/memcg: unify swap and memsw page counters") Reported-by: kernel test robot Signed-off-by: Feng Tang Acked-by: Waiman Long Signed-off-by: Linus Torvalds --- include/linux/memcontrol.h | 28 ++++++++++++++-------------- 1 file changed, 14 insertions(+), 14 deletions(-) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index a80c59af2c60..922a7f600465 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -282,20 +282,6 @@ struct mem_cgroup { MEMCG_PADDING(_pad1_); - /* - * set > 0 if pages under this cgroup are moving to other cgroup. - */ - atomic_t moving_account; - struct task_struct *move_lock_task; - - /* Legacy local VM stats and events */ - struct memcg_vmstats_percpu __percpu *vmstats_local; - - /* Subtree VM stats and events (batched updates) */ - struct memcg_vmstats_percpu __percpu *vmstats_percpu; - - MEMCG_PADDING(_pad2_); - atomic_long_t vmstats[MEMCG_NR_STAT]; atomic_long_t vmevents[NR_VM_EVENT_ITEMS]; @@ -317,6 +303,20 @@ struct mem_cgroup { struct list_head objcg_list; /* list of inherited objcgs */ #endif + MEMCG_PADDING(_pad2_); + + /* + * set > 0 if pages under this cgroup are moving to other cgroup. + */ + atomic_t moving_account; + struct task_struct *move_lock_task; + + /* Legacy local VM stats and events */ + struct memcg_vmstats_percpu __percpu *vmstats_local; + + /* Subtree VM stats and events (batched updates) */ + struct memcg_vmstats_percpu __percpu *vmstats_percpu; + #ifdef CONFIG_CGROUP_WRITEBACK struct list_head cgwb_list; struct wb_domain cgwb_domain;