From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ed1-f71.google.com (mail-ed1-f71.google.com [209.85.208.71]) by kanga.kvack.org (Postfix) with ESMTP id 53E4B8E00C2 for ; Fri, 25 Jan 2019 02:24:34 -0500 (EST) Received: by mail-ed1-f71.google.com with SMTP id c53so3373533edc.9 for ; Thu, 24 Jan 2019 23:24:34 -0800 (PST) Received: from mx1.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id kq26si1441069ejb.228.2019.01.24.23.24.32 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 24 Jan 2019 23:24:32 -0800 (PST) Date: Fri, 25 Jan 2019 08:24:29 +0100 From: Michal Hocko Subject: Re: [PATCH 2/2] mm: Extract memcg maxable seq_file logic to seq_show_memcg_tunable Message-ID: <20190125072429.GA3560@dhcp22.suse.cz> References: <20190124194100.GA31425@chrisdown.name> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190124194100.GA31425@chrisdown.name> Sender: owner-linux-mm@kvack.org List-ID: To: Chris Down Cc: Andrew Morton , Johannes Weiner , Tejun Heo , Roman Gushchin , linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, linux-mm@kvack.org, kernel-team@fb.com On Thu 24-01-19 14:41:00, Chris Down wrote: > 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. Yeah this is what I've had in mind when mentioning a helper in the previous version of the patch. I like this more even though the resulting savings are not that large. > Signed-off-by: Chris Down > Cc: Andrew Morton > Cc: Johannes Weiner > Cc: Tejun Heo > Cc: Roman Gushchin > Cc: linux-kernel@vger.kernel.org > Cc: cgroups@vger.kernel.org > Cc: linux-mm@kvack.org > Cc: kernel-team@fb.com Acked-by: Michal Hocko > --- > mm/memcontrol.c | 64 +++++++++++++++---------------------------------- > 1 file changed, 19 insertions(+), 45 deletions(-) > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index 98aad31f5226..81b6f752471a 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -5375,6 +5375,16 @@ static void mem_cgroup_bind(struct cgroup_subsys_state *root_css) > 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) > { > @@ -5385,15 +5395,8 @@ static u64 memory_current_read(struct cgroup_subsys_state *css, > > 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, > @@ -5415,15 +5418,8 @@ static ssize_t memory_min_write(struct kernfs_open_file *of, > > 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, > @@ -5445,15 +5441,7 @@ static ssize_t memory_low_write(struct kernfs_open_file *of, > > 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, > @@ -5482,15 +5470,8 @@ static ssize_t memory_high_write(struct kernfs_open_file *of, > > 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, > @@ -6622,15 +6603,8 @@ static u64 swap_current_read(struct cgroup_subsys_state *css, > > 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, > -- > 2.20.1 -- Michal Hocko SUSE Labs