From mboxrd@z Thu Jan 1 00:00:00 1970 From: Johannes Weiner Subject: Re: [PATCH v5] mm: memcontrol: Add the missing numa_stat interface for cgroup v2 Date: Tue, 15 Sep 2020 17:48:45 -0400 Message-ID: <20200915214845.GB189808@cmpxchg.org> References: <20200915171801.39761-1-songmuchun@bytedance.com> Mime-Version: 1.0 Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cmpxchg-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=gwAGdDXVM4r4OL55XSo1884lNeDAwaOm7bwctRtLrys=; b=uOWcBox38dGodh/iQrPqVF2GLIJyW9L4Y3ANaEZXp2ypNq6/uKrX+x43BZP8K1yuwB TjBbkfHme3SAZjHyCDwS27BnDVQcAodcI29aOajz9qZKP6YTdfgiHiG7ERgW0xkoMkZc vnnYhnh1hdS2aYSiqfXF918Ttjkg/AZluGilhI1SM4HJ2oSeNm8sbJrtEH/4xheskIPM Fn349hTQnPUj1MoyZwZEIsaKO2GhGt3GRpPEws4hszG3mSahAm4PmzMdhBav2zpg/aGG GkAk3u/IFwWEN8bb5pmjgdXCg+UJyIAZ1cTAk/PMXcWapHOK0hyjAleZE0fB0RVgd8O4 IhMA== Content-Disposition: inline In-Reply-To: <20200915171801.39761-1-songmuchun-EC8Uxl6Npydl57MIdRCFDg@public.gmane.org> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Muchun Song Cc: tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org, corbet-T1hC0tSOHrs@public.gmane.org, mhocko-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, vdavydov.dev-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org, shakeelb-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, guro-b10kYP2dOMg@public.gmane.org, rdunlap-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-doc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org On Wed, Sep 16, 2020 at 01:18:01AM +0800, Muchun Song wrote: > In the cgroup v1, we have a numa_stat interface. This is useful for > providing visibility into the numa locality information within an > memcg since the pages are allowed to be allocated from any physical > node. One of the use cases is evaluating application performance by > combining this information with the application's CPU allocation. > But the cgroup v2 does not. So this patch adds the missing information. > > Signed-off-by: Muchun Song > Suggested-by: Shakeel Butt > Reviewed-by: Shakeel Butt Yup, that would be useful information to have. Just a few comments on the patch below: > @@ -1368,6 +1368,78 @@ PAGE_SIZE multiple when read back. > collapsing an existing range of pages. This counter is not > present when CONFIG_TRANSPARENT_HUGEPAGE is not set. > > + memory.numa_stat > + A read-only flat-keyed file which exists on non-root cgroups. It's a nested key file, not flat. > + This breaks down the cgroup's memory footprint into different > + types of memory, type-specific details, and other information > + per node on the state of the memory management system. > + > + This is useful for providing visibility into the NUMA locality > + information within an memcg since the pages are allowed to be > + allocated from any physical node. One of the use case is evaluating > + application performance by combining this information with the > + application's CPU allocation. > + > + All memory amounts are in bytes. > + > + The output format of memory.numa_stat is:: > + > + type N0= N1= ... > + > + The entries are ordered to be human readable, and new entries > + can show up in the middle. Don't rely on items remaining in a > + fixed position; use the keys to look up specific values! > + > + anon > + Amount of memory per node used in anonymous mappings such > + as brk(), sbrk(), and mmap(MAP_ANONYMOUS). > + > + file > + Amount of memory per node used to cache filesystem data, > + including tmpfs and shared memory. > + > + kernel_stack > + Amount of memory per node allocated to kernel stacks. > + > + shmem > + Amount of cached filesystem data per node that is swap-backed, > + such as tmpfs, shm segments, shared anonymous mmap()s. > + > + file_mapped > + Amount of cached filesystem data per node mapped with mmap(). > + > + file_dirty > + Amount of cached filesystem data per node that was modified but > + not yet written back to disk. > + > + file_writeback > + Amount of cached filesystem data per node that was modified and > + is currently being written back to disk. > + > + anon_thp > + Amount of memory per node used in anonymous mappings backed by > + transparent hugepages. > + > + inactive_anon, active_anon, inactive_file, active_file, unevictable > + Amount of memory, swap-backed and filesystem-backed, > + per node on the internal memory management lists used > + by the page reclaim algorithm. > + > + As these represent internal list state (e.g. shmem pages are on > + anon memory management lists), inactive_foo + active_foo may not > + be equal to the value for the foo counter, since the foo counter > + is type-based, not list-based. > + > + slab_reclaimable > + Amount of memory per node used for storing in-kernel data > + structures which might be reclaimed, such as dentries and > + inodes. > + > + slab_unreclaimable > + Amount of memory per node used for storing in-kernel data > + structures which cannot be reclaimed on memory pressure. > + > memory.swap.current > A read-only single value file which exists on non-root > cgroups. > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index 75cd1a1e66c8..ff919ef3b57b 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -6425,6 +6425,86 @@ static int memory_stat_show(struct seq_file *m, void *v) > return 0; > } > > +#ifdef CONFIG_NUMA > +struct numa_stat { > + const char *name; > + unsigned int ratio; > + enum node_stat_item idx; > +}; > + > +static struct numa_stat numa_stats[] = { > + { "anon", PAGE_SIZE, NR_ANON_MAPPED }, > + { "file", PAGE_SIZE, NR_FILE_PAGES }, > + { "kernel_stack", 1024, NR_KERNEL_STACK_KB }, > + { "shmem", PAGE_SIZE, NR_SHMEM }, > + { "file_mapped", PAGE_SIZE, NR_FILE_MAPPED }, > + { "file_dirty", PAGE_SIZE, NR_FILE_DIRTY }, > + { "file_writeback", PAGE_SIZE, NR_WRITEBACK }, > +#ifdef CONFIG_TRANSPARENT_HUGEPAGE > + /* > + * The ratio will be initialized in numa_stats_init(). Because > + * on some architectures, the macro of HPAGE_PMD_SIZE is not > + * constant(e.g. powerpc). > + */ > + { "anon_thp", 0, NR_ANON_THPS }, > +#endif > + { "inactive_anon", PAGE_SIZE, NR_INACTIVE_ANON }, > + { "active_anon", PAGE_SIZE, NR_ACTIVE_ANON }, > + { "inactive_file", PAGE_SIZE, NR_INACTIVE_FILE }, > + { "active_file", PAGE_SIZE, NR_ACTIVE_FILE }, > + { "unevictable", PAGE_SIZE, NR_UNEVICTABLE }, > + { "slab_reclaimable", 1, NR_SLAB_RECLAIMABLE_B }, > + { "slab_unreclaimable", 1, NR_SLAB_UNRECLAIMABLE_B }, > +}; This is a bit duplicative with memory_stat_format(), and the collections will easily go out of sync as we add/change stat items. Can you please convert memory_stat_format() to use the same shared table? You may have to add another flag for the MEMCG_* items for which we don't have per-node counters. The same applies to the documentation. Please don't duplicate the list of items, but have memory.numa_stat refer to the list for memory.stat. You can add (not in memory.numa_stat) or something to percpu and sock. > +static unsigned long memcg_node_page_state(struct mem_cgroup *memcg, > + unsigned int nid, > + enum node_stat_item idx) > +{ > + VM_BUG_ON(nid >= nr_node_ids); > + return lruvec_page_state(mem_cgroup_lruvec(memcg, NODE_DATA(nid)), idx); > +} Please drop this wrapper and use lruvec_page_state directly below. Otherwise, this looks reasonable to me.