From: Chris Down <chris@xxxxxxxxxxxxxx> Subject: mm, memcg: extract memcg maxable seq_file logic to seq_show_memcg_tunable memcg has a significant number of files exposed to kernfs where their value is either exposed directly or is "max" in the case of PAGE_COUNTER_MAX. This patch makes this generic by providing a single function to do this work. In combination with the previous patch adding mem_cgroup_from_seq, this makes all of the seq_show feeder functions significantly more simple. Link: http://lkml.kernel.org/r/20190124194100.GA31425@xxxxxxxxxxxxxx Signed-off-by: Chris Down <chris@xxxxxxxxxxxxxx> Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx> Acked-by: Michal Hocko <mhocko@xxxxxxxx> Cc: Tejun Heo <tj@xxxxxxxxxx> Cc: Roman Gushchin <guro@xxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/memcontrol.c | 64 +++++++++++++--------------------------------- 1 file changed, 19 insertions(+), 45 deletions(-) --- a/mm/memcontrol.c~mm-extract-memcg-maxable-seq_file-logic-to-seq_show_memcg_tunable +++ a/mm/memcontrol.c @@ -5353,6 +5353,16 @@ static void mem_cgroup_bind(struct cgrou root_mem_cgroup->use_hierarchy = false; } +static int seq_puts_memcg_tunable(struct seq_file *m, unsigned long value) +{ + if (value == PAGE_COUNTER_MAX) + seq_puts(m, "max\n"); + else + seq_printf(m, "%llu\n", (u64)value * PAGE_SIZE); + + return 0; +} + static u64 memory_current_read(struct cgroup_subsys_state *css, struct cftype *cft) { @@ -5363,15 +5373,8 @@ static u64 memory_current_read(struct cg static int memory_min_show(struct seq_file *m, void *v) { - struct mem_cgroup *memcg = mem_cgroup_from_seq(m); - unsigned long min = READ_ONCE(memcg->memory.min); - - if (min == PAGE_COUNTER_MAX) - seq_puts(m, "max\n"); - else - seq_printf(m, "%llu\n", (u64)min * PAGE_SIZE); - - return 0; + return seq_puts_memcg_tunable(m, + READ_ONCE(mem_cgroup_from_seq(m)->memory.min)); } static ssize_t memory_min_write(struct kernfs_open_file *of, @@ -5393,15 +5396,8 @@ static ssize_t memory_min_write(struct k static int memory_low_show(struct seq_file *m, void *v) { - struct mem_cgroup *memcg = mem_cgroup_from_seq(m); - unsigned long low = READ_ONCE(memcg->memory.low); - - if (low == PAGE_COUNTER_MAX) - seq_puts(m, "max\n"); - else - seq_printf(m, "%llu\n", (u64)low * PAGE_SIZE); - - return 0; + return seq_puts_memcg_tunable(m, + READ_ONCE(mem_cgroup_from_seq(m)->memory.low)); } static ssize_t memory_low_write(struct kernfs_open_file *of, @@ -5423,15 +5419,7 @@ static ssize_t memory_low_write(struct k static int memory_high_show(struct seq_file *m, void *v) { - struct mem_cgroup *memcg = mem_cgroup_from_seq(m); - unsigned long high = READ_ONCE(memcg->high); - - if (high == PAGE_COUNTER_MAX) - seq_puts(m, "max\n"); - else - seq_printf(m, "%llu\n", (u64)high * PAGE_SIZE); - - return 0; + return seq_puts_memcg_tunable(m, READ_ONCE(mem_cgroup_from_seq(m)->high)); } static ssize_t memory_high_write(struct kernfs_open_file *of, @@ -5460,15 +5448,8 @@ static ssize_t memory_high_write(struct static int memory_max_show(struct seq_file *m, void *v) { - struct mem_cgroup *memcg = mem_cgroup_from_seq(m); - unsigned long max = READ_ONCE(memcg->memory.max); - - if (max == PAGE_COUNTER_MAX) - seq_puts(m, "max\n"); - else - seq_printf(m, "%llu\n", (u64)max * PAGE_SIZE); - - return 0; + return seq_puts_memcg_tunable(m, + READ_ONCE(mem_cgroup_from_seq(m)->memory.max)); } static ssize_t memory_max_write(struct kernfs_open_file *of, @@ -6600,15 +6581,8 @@ static u64 swap_current_read(struct cgro static int swap_max_show(struct seq_file *m, void *v) { - struct mem_cgroup *memcg = mem_cgroup_from_seq(m); - unsigned long max = READ_ONCE(memcg->swap.max); - - if (max == PAGE_COUNTER_MAX) - seq_puts(m, "max\n"); - else - seq_printf(m, "%llu\n", (u64)max * PAGE_SIZE); - - return 0; + return seq_puts_memcg_tunable(m, + READ_ONCE(mem_cgroup_from_seq(m)->swap.max)); } static ssize_t swap_max_write(struct kernfs_open_file *of, _
