Re: [PATCH][RFC] dirty balancing for cgroups

KAMEZAWA Hiroyuki
2008-07-10T23:49:02Z

On Wed, 9 Jul 2008 15:00:34 +0900 (JST)
yamamoto@valinux.co.jp (YAMAMOTO Takashi) wrote:

> hi,
>
> the following patch is a simple implementation of
> dirty balancing for cgroups. any comments?
>
> it depends on the following fix:
> http://lkml.org/lkml/2008/7/8/428
>

A few comments ;)

- This looks simple but, could you merge this into memory resource controller ?
(if conflict, I'll queue on my stack.)
- Do you have some number ? or How we can test this works well ?
- please CC to linux-mm.

Thanks,
-Kame

> YAMAMOTO Takashi
>
>
> Signed-off-by: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
> ---
>
> diff --git a/include/linux/cgroup_subsys.h b/include/linux/cgroup_subsys.h
> index 23c02e2..f5453cc 100644
> --- a/include/linux/cgroup_subsys.h
> +++ b/include/linux/cgroup_subsys.h
> @@ -52,3 +52,9 @@ SUBSYS(memrlimit_cgroup)
> #endif
>
> /* */
> +
> +#ifdef CONFIG_CGROUP_MEMDIRTYLIMIT_CTLR
> +SUBSYS(memdirtylimit_cgroup)
> +#endif
> +
> +/* */
> diff --git a/include/linux/memdirtylimitcgroup.h b/include/linux/memdirtylimitcgroup.h
> new file mode 100644
> index 0000000..667d312
> --- /dev/null
> +++ b/include/linux/memdirtylimitcgroup.h
> @@ -0,0 +1,47 @@
> +
> +/*
> + * memdirtylimitcgroup.h COPYRIGHT FUJITSU LIMITED 2008
> + *
> + * Author: yamamoto@valinux.co.jp
> + */
> +
> +struct task_struct;
> +
> +#if defined(CONFIG_CGROUP_MEMDIRTYLIMIT_CTLR)
> +
> +void memdirtylimitcgroup_dirty_inc(struct task_struct *);
> +void memdirtylimitcgroup_dirty_limit(struct task_struct *, long *);
> +void memdirtylimitcgroup_change_shift(int);
> +void memdirtylimitcgroup_init(int);
> +
> +#else /* defined(CONFIG_CGROUP_MEMDIRTYLIMIT_CTLR) */
> +
> +static inline void
> +memdirtylimitcgroup_dirty_inc(struct task_struct *t)
> +{
> +
> + /* nothing */
> +}
> +
> +static inline void
> +memdirtylimitcgroup_dirty_limit(struct task_struct *t, long *dirtyp)
> +{
> +
> + /* nothing */
> +}
> +
> +static inline void
> +memdirtylimitcgroup_change_shift(int shift)
> +{
> +
> + /* nothing */
> +}
> +
> +static inline void
> +memdirtylimitcgroup_init(int shift)
> +{
> +
> + /* nothing */
> +}
> +
> +#endif /* defined(CONFIG_CGROUP_MEMDIRTYLIMIT_CTLR) */
> diff --git a/init/Kconfig b/init/Kconfig
> index 162d462..985bac8 100644
> --- a/init/Kconfig
> +++ b/init/Kconfig
> @@ -418,6 +418,12 @@ config CGROUP_MEMRLIMIT_CTLR
> memory RSS and Page Cache control. Virtual address space control
> is provided by this controller.
>
> +config CGROUP_MEMDIRTYLIMIT_CTLR
> + bool "Memory Dirty Limit Controller for Control Groups"
> + depends on CGROUPS && RESOURCE_COUNTERS
> + help
> + XXX TBD
> +
> config SYSFS_DEPRECATED
> bool
>
> diff --git a/mm/Makefile b/mm/Makefile
> index f54232d..8603d19 100644
> --- a/mm/Makefile
> +++ b/mm/Makefile
> @@ -35,4 +35,5 @@ obj-$(CONFIG_SMP) += allocpercpu.o
> obj-$(CONFIG_QUICKLIST) += quicklist.o
> obj-$(CONFIG_CGROUP_MEM_RES_CTLR) += memcontrol.o
> obj-$(CONFIG_CGROUP_MEMRLIMIT_CTLR) += memrlimitcgroup.o
> +obj-$(CONFIG_CGROUP_MEMDIRTYLIMIT_CTLR) += memdirtylimitcgroup.o
> obj-$(CONFIG_MMU_NOTIFIER) += mmu_notifier.o
> diff --git a/mm/memdirtylimitcgroup.c b/mm/memdirtylimitcgroup.c
> new file mode 100644
> index 0000000..b70b33d
> --- /dev/null
> +++ b/mm/memdirtylimitcgroup.c
> @@ -0,0 +1,179 @@
> +
> +/*
> + * memdirtylimitcgroup.c COPYRIGHT FUJITSU LIMITED 2008
> + *
> + * Author: yamamoto@valinux.co.jp
> + */
> +
> +#include <linux/err.h>
> +#include <linux/cgroup.h>
> +#include <linux/rcupdate.h>
> +#include <linux/slab.h>
> +#include <linux/memdirtylimitcgroup.h>
> +
> +#include <asm/div64.h>
> +
> +static struct prop_descriptor vm_cgroup_dirties;
> +
> +struct memdirtylimit_cgroup {
> + struct cgroup_subsys_state dlcg_css;
> + spinlock_t dlcg_lock;
> + struct prop_local_single dlcg_dirties;
> +};
> +
> +static struct cgroup_subsys_state *
> +task_to_css(struct task_struct *task)
> +{
> +
> + return task_subsys_state(task, memdirtylimit_cgroup_subsys_id);
> +}
> +
> +static struct memdirtylimit_cgroup *
> +css_to_dlcg(struct cgroup_subsys_state *css)
> +{
> +
> + return container_of(css, struct memdirtylimit_cgroup, dlcg_css);
> +}
> +
> +static struct cgroup_subsys_state *
> +cg_to_css(struct cgroup *cg)
> +{
> +
> + return cgroup_subsys_state(cg, memdirtylimit_cgroup_subsys_id);
> +}
> +
> +static struct memdirtylimit_cgroup *
> +cg_to_dlcg(struct cgroup *cg)
> +{
> +
> + return css_to_dlcg(cg_to_css(cg));
> +}
> +
> +/* ---------------------------------------- */
> +
> +static void
> +getfraction(struct memdirtylimit_cgroup *dlcg, long *numeratorp,
> + long *denominatorp)
> +{
> +
> + spin_lock(&dlcg->dlcg_lock);
> + prop_fraction_single(&vm_cgroup_dirties, &dlcg->dlcg_dirties,
> + numeratorp, denominatorp);
> + spin_unlock(&dlcg->dlcg_lock);
> +}
> +
> +/* ---------------------------------------- */
> +
> +void
> +memdirtylimitcgroup_dirty_inc(struct task_struct *t)
> +{
> + struct memdirtylimit_cgroup *dlcg;
> +
> + rcu_read_lock();
> + dlcg = css_to_dlcg(task_to_css(t));
> + spin_lock(&dlcg->dlcg_lock);
> + prop_inc_single(&vm_cgroup_dirties, &dlcg->dlcg_dirties);
> + spin_unlock(&dlcg->dlcg_lock);
> + rcu_read_unlock();
> +}
> +
> +void
> +memdirtylimitcgroup_dirty_limit(struct task_struct *t, long *dirtyp)
> +{
> + struct memdirtylimit_cgroup *dlcg;
> + unsigned long dirty = *dirtyp;
> + uint64_t tmp;
> + long numerator;
> + long denominator;
> +
> + BUG_ON(*dirtyp < 0);
> +
> + rcu_read_lock();
> + dlcg = css_to_dlcg(task_to_css(t));
> + getfraction(dlcg, &numerator, &denominator);
> + rcu_read_unlock();
> +
> + tmp = (uint64_t)(dirty >> 1) * numerator;
> + do_div(tmp, denominator);
> + *dirtyp = dirty - (unsigned long)tmp;
> +}
> +
> +void
> +memdirtylimitcgroup_change_shift(int shift)
> +{
> +
> + prop_change_shift(&vm_cgroup_dirties, shift);
> +}
> +
> +void
> +memdirtylimitcgroup_init(int shift)
> +{
> +
> + prop_descriptor_init(&vm_cgroup_dirties, shift);
> +}
> +
> +/* ---------------------------------------- */
> +
> +static u64
> +memdirtylimit_cgroup_read_fraction(struct cgroup *cg, struct cftype *cft)
> +{
> + struct memdirtylimit_cgroup *dlcg;
> + uint64_t result;
> + long numerator;
> + long denominator;
> +
> + dlcg = cg_to_dlcg(cg);
> + getfraction(dlcg, &numerator, &denominator);
> + result = (uint64_t)100 * numerator;
> + do_div(result, denominator);
> + return result;
> +}
> +
> +static const struct cftype files[] = {
> + {
> + .name = "fraction",
> + .read_u64 = memdirtylimit_cgroup_read_fraction,
> + },
> +};
> +
> +static int
> +memdirtylimit_cgroup_populate(struct cgroup_subsys *ss, struct cgroup *cg)
> +{
> +
> + return cgroup_add_files(cg, ss, files, ARRAY_SIZE(files));
> +}
> +
> +static struct cgroup_subsys_state *
> +memdirtylimit_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cg)
> +{
> + struct memdirtylimit_cgroup *dlcg;
> + int error;
> +
> + dlcg = kzalloc(sizeof(*dlcg), GFP_KERNEL);
> + if (dlcg == NULL)
> + return ERR_PTR(-ENOMEM);
> + error = prop_local_init_single(&dlcg->dlcg_dirties);
> + if (error != 0) {
> + kfree(dlcg);
> + return ERR_PTR(error);
> + }
> + spin_lock_init(&dlcg->dlcg_lock);
> + return &dlcg->dlcg_css;
> +}
> +
> +static void
> +memdirtylimit_cgroup_destroy(struct cgroup_subsys *ss, struct cgroup *cg)
> +{
> + struct memdirtylimit_cgroup *dlcg = cg_to_dlcg(cg);
> +
> + prop_local_destroy_single(&dlcg->dlcg_dirties);
> + kfree(dlcg);
> +}
> +
> +struct cgroup_subsys memdirtylimit_cgroup_subsys = {
> + .name = "memdirtylimit",
> + .subsys_id = memdirtylimit_cgroup_subsys_id,
> + .create = memdirtylimit_cgroup_create,
> + .destroy = memdirtylimit_cgroup_destroy,
> + .populate = memdirtylimit_cgroup_populate,
> +};
> diff --git a/mm/page-writeback.c b/mm/page-writeback.c
> index e6fa69e..f971532 100644
> --- a/mm/page-writeback.c
> +++ b/mm/page-writeback.c
> @@ -34,6 +34,7 @@
> #include <linux/syscalls.h>
> #include <linux/buffer_head.h>
> #include <linux/pagevec.h>
> +#include <linux/memdirtylimitcgroup.h>
>
> /*
> * The maximum number of pages to writeout in a single bdflush/kupdate
> @@ -152,6 +153,7 @@ int dirty_ratio_handler(struct ctl_table *table, int write,
> int shift = calc_period_shift();
> prop_change_shift(&vm_completions, shift);
> prop_change_shift(&vm_dirties, shift);
> + memdirtylimitcgroup_change_shift(shift);
> }
> return ret;
> }
> @@ -393,6 +395,8 @@ get_dirty_limits(long *pbackground, long *pdirty, long *pbdi_dirty,
> if (bdi) {
> u64 bdi_dirty;
> long numerator, denominator;
> + long task_dirty;
> + long cgroup_dirty;
>
> /*
> * Calculate this BDI's share of the dirty ratio.
> @@ -408,7 +412,11 @@ get_dirty_limits(long *pbackground, long *pdirty, long *pbdi_dirty,
>
> *pbdi_dirty = bdi_dirty;
> clip_bdi_dirty_limit(bdi, dirty, pbdi_dirty);
> - task_dirty_limit(current, pbdi_dirty);
> + task_dirty = *pbdi_dirty;
> + task_dirty_limit(current, &task_dirty);
> + cgroup_dirty = *pbdi_dirty;
> + memdirtylimitcgroup_dirty_limit(current, &cgroup_dirty);
> + *pbdi_dirty = min(task_dirty, cgroup_dirty);
> }
> }
>
> @@ -842,6 +850,7 @@ void __init page_writeback_init(void)
> shift = calc_period_shift();
> prop_descriptor_init(&vm_completions, shift);
> prop_descriptor_init(&vm_dirties, shift);
> + memdirtylimitcgroup_init(shift);
> }
>
> /**
> @@ -1105,6 +1114,7 @@ int __set_page_dirty_nobuffers(struct page *page)
> }
>
> task_dirty_inc(current);
> + memdirtylimitcgroup_dirty_inc(current);
>
> return 1;
> }
>