在 2023/12/14 20:55, Kefeng Wang 写道:

这个地方要不要新加一个逻辑： 考虑后续新pid加入到cgroup里面情况；

我们memcg->ksm接口只是做使能； 1） 当前实现，遍历已有的使能ksm 2） 新加入pid，需要查看遍历使能ksm

等姚路路来了让他做，包括其他KSM相关的几个需求一起做了

On 2023/12/14 21:38, Nanyong Sun wrote:

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hulk inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8OIQR

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Add control file "memory.ksm" to enable ksm per cgroup. Echo to 1 will set all tasks currently in the cgroup to ksm merge any mode, which means ksm gets enabled for all vma's of a process. Meanwhile echo to 0 will disable ksm for them and unmerge the merged pages. Cat the file will show the above state and ksm related profits of this cgroup.

Signed-off-by: Nanyong Sun sunnanyong@huawei.com

.../admin-guide/cgroup-v1/memory.rst          |   1 +   mm/memcontrol.c                               | 110 +++++++++++++++++-   2 files changed, 109 insertions(+), 2 deletions(-)

diff --git a/Documentation/admin-guide/cgroup-v1/memory.rst b/Documentation/admin-guide/cgroup-v1/memory.rst index ff456871bf4b..3fdb48435e8e 100644 --- a/Documentation/admin-guide/cgroup-v1/memory.rst +++ b/Documentation/admin-guide/cgroup-v1/memory.rst @@ -109,6 +109,7 @@ Brief summary of control files.    memory.kmem.tcp.failcnt             show the number of tcp buf memory usage                        hits limits    memory.kmem.tcp.max_usage_in_bytes  show max tcp buf memory usage recorded

• memory.ksm                          set/show ksm merge any mode

====================================

1. History diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 8a881ab21f6c..be37c2dda785 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -73,6 +73,7 @@   #include <linux/uaccess.h>     #include <trace/events/vmscan.h> +#include <linux/ksm.h>     struct cgroup_subsys memory_cgrp_subsys __read_mostly;   EXPORT_SYMBOL(memory_cgrp_subsys); @@ -230,10 +231,15 @@ enum res_type {            iter != NULL;                \            iter = mem_cgroup_iter(NULL, iter, NULL))   +static inline bool __task_is_dying(struct task_struct *task) +{ +    return tsk_is_oom_victim(task) || fatal_signal_pending(task) || +        (task->flags & PF_EXITING); +}

static inline bool task_is_dying(void)   { -    return tsk_is_oom_victim(current) || fatal_signal_pending(current) || -        (current->flags & PF_EXITING); +    return __task_is_dying(current);   }     /* Some nice accessors for the vmpressure. */ @@ -5010,6 +5016,98 @@ static int mem_cgroup_slab_show(struct seq_file *m, void *p)   }   #endif   +#ifdef CONFIG_KSM +static int memcg_set_ksm_for_tasks(struct mem_cgroup *memcg, bool enable) +{ +    struct task_struct *task; +    struct mm_struct *mm; +    struct css_task_iter it; +    int ret = 0;

+    css_task_iter_start(&memcg->css, CSS_TASK_ITER_PROCS, &it); +    while (!ret && (task = css_task_iter_next(&it))) { +        if (__task_is_dying(task)) +            continue;

+        mm = get_task_mm(task); +        if (!mm) +            continue;

+        if (mmap_write_lock_killable(mm)) { +            mmput(mm); +            continue; +        }

+        if (enable) +            ret = ksm_enable_merge_any(mm); +        else +            ret = ksm_disable_merge_any(mm);

+        mmap_write_unlock(mm); +        mmput(mm); +    } +    css_task_iter_end(&it);

+    return ret; +}

+static int memory_ksm_show(struct seq_file *m, void *v) +{ +    unsigned long ksm_merging_pages = 0; +    unsigned long ksm_rmap_items = 0; +    long ksm_process_profits = 0; +    unsigned int tasks = 0; +    struct task_struct *task; +    struct mm_struct *mm; +    struct css_task_iter it; +    struct mem_cgroup *memcg = mem_cgroup_from_seq(m);

+    css_task_iter_start(&memcg->css, CSS_TASK_ITER_PROCS, &it); +    while ((task = css_task_iter_next(&it))) { +        mm = get_task_mm(task); +        if (!mm) +            continue;

+        if (test_bit(MMF_VM_MERGE_ANY, &mm->flags)) +            tasks++;

+        ksm_rmap_items += mm->ksm_rmap_items; +        ksm_merging_pages += mm->ksm_merging_pages; +        ksm_process_profits += ksm_process_profit(mm); +        mmput(mm); +    } +    css_task_iter_end(&it);

+    seq_printf(m, "merge any tasks: %u\n", tasks); +    seq_printf(m, "ksm_rmap_items %lu\n", ksm_rmap_items); +    seq_printf(m, "ksm_merging_pages %lu\n", ksm_merging_pages); +    seq_printf(m, "ksm_process_profits %ld\n", ksm_process_profits); +    return 0; +}

+static ssize_t memory_ksm_write(struct kernfs_open_file *of, char *buf, +                    size_t nbytes, loff_t off) +{ +    bool enable; +    int err; +    struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of));

+    buf = strstrip(buf); +    if (!buf) +        return -EINVAL;

+    err = kstrtobool(buf, &enable); +    if (err) +        return err;

+    err = memcg_set_ksm_for_tasks(memcg, enable); +    if (err) +        return err;

+    return nbytes; +} +#endif /* CONFIG_KSM */

static int memory_stat_show(struct seq_file *m, void *v);     static struct cftype mem_cgroup_legacy_files[] = { @@ -5138,6 +5236,14 @@ static struct cftype mem_cgroup_legacy_files[] = {           .write = mem_cgroup_reset,           .read_u64 = mem_cgroup_read_u64,       }, +#ifdef CONFIG_KSM +    { +        .name = "ksm", +        .flags = CFTYPE_NOT_ON_ROOT, +        .write = memory_ksm_write, +        .seq_show = memory_ksm_show, +    }, +#endif       { },    /* terminate */   };

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