From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9CF7FC433EF for ; Thu, 11 Nov 2021 02:37:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7656A61354 for ; Thu, 11 Nov 2021 02:37:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233573AbhKKCjr (ORCPT ); Wed, 10 Nov 2021 21:39:47 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38604 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233061AbhKKCjq (ORCPT ); Wed, 10 Nov 2021 21:39:46 -0500 Received: from mail-yb1-xb36.google.com (mail-yb1-xb36.google.com [IPv6:2607:f8b0:4864:20::b36]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B8E50C061766 for ; Wed, 10 Nov 2021 18:36:57 -0800 (PST) Received: by mail-yb1-xb36.google.com with SMTP id 131so11392557ybc.7 for ; Wed, 10 Nov 2021 18:36:57 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20210112.gappssmtp.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=NqctALwMz4c+px2fGda2fQ0bf3yBC/4iDfvjem4l/kQ=; b=mWByVKqSmeYdggMqp+elJHoij/9RHfl/7mHDpsXDmQkVNRHdnG65lrh3s9/8+2Dd/R Wv2kELS1xvLjot1c1BWvssTMD8EcGmQg1ns2/P0IoTwwByUOD/zBMSPwILtmaYGDE4nK FXXNM7a3FndZAomXcKWnaRQMZ+/L0U8wTD+EnW7d4T7iVzImCtRLB7GsrPm4v4/1lUT6 Na4z6j+LbY9QwpVJgzLSYow+ihmi10yPIKJ2mycy8sOHiM2iGvmKDBciVjpBzcg3CsWY 6t3dzOh+ozcxj0a5m9L5YoLnbihSc5MSO6btDGDpBize8iunnZ+oluw8fPNaMVG20/Wm HUBw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=NqctALwMz4c+px2fGda2fQ0bf3yBC/4iDfvjem4l/kQ=; b=WlPfkP6RXzJ9gOEzVcklH6LSSCYSPbvNN9Nkw44AP25ocwGVEKLaSg1pLy3QOXjdtj cI0RdkMenlfmHQFviP03brUZJzAMmBuXYNztm/MG03bTwOpoBsfcVpR8O89QlVeTQrTP hv53QeZ12blSIHAZTxsoxFNuvCf7VdYqiPXDaKIkrPMVZQ4lm7ThEYBVK5aGzUmt1v2M tOQ+I2tE+9PhaLqoOBgJxGC40JPOSKdjIp2ZSNx6ZsSJ9zeg/rL5p3Y6Rsk7vUPG9SoE TpGn5r2up15j1+XsU+QbK3dWFFaMkv0qNDDY9B4OCMy5s9YpSeNNKp+U2C2YGlCOL6Im BQtg== X-Gm-Message-State: AOAM532z4OBnHVQOZgPR6I/Xlc4ARZOp4Kif+O6LQQzkCirhJePs0EHI 7P2aTzpwghyjXhBj9qxQR5XZtJInhfqFSHthQ7eozA== X-Google-Smtp-Source: ABdhPJyHOm6Y4ULjM8ZgZDqdaUKlK/ybR/IFS8Rsc1lVKxANExzIIe2usY5PwMFzpu74QTqiu39euYf9Z5FNix5xGPg= X-Received: by 2002:a25:b0a8:: with SMTP id f40mr4189292ybj.125.1636598216802; Wed, 10 Nov 2021 18:36:56 -0800 (PST) MIME-Version: 1.0 References: <20211111015037.4092956-1-almasrymina@google.com> In-Reply-To: <20211111015037.4092956-1-almasrymina@google.com> From: Muchun Song Date: Thu, 11 Nov 2021 10:36:20 +0800 Message-ID: Subject: Re: [PATCH v6] hugetlb: Add hugetlb.*.numa_stat file To: Mina Almasry Cc: Mike Kravetz , Andrew Morton , Shuah Khan , Miaohe Lin , Oscar Salvador , Michal Hocko , David Rientjes , Shakeel Butt , Jue Wang , Yang Yao , Joanna Li , Cannon Matthews , Linux Memory Management List , LKML Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Nov 11, 2021 at 9:50 AM Mina Almasry wrote= : > > For hugetlb backed jobs/VMs it's critical to understand the numa > information for the memory backing these jobs to deliver optimal > performance. > > Currently this technically can be queried from /proc/self/numa_maps, but > there are significant issues with that. Namely: > 1. Memory can be mapped or unmapped. > 2. numa_maps are per process and need to be aggregated across all > processes in the cgroup. For shared memory this is more involved as > the userspace needs to make sure it doesn't double count shared > mappings. > 3. I believe querying numa_maps needs to hold the mmap_lock which adds > to the contention on this lock. > > For these reasons I propose simply adding hugetlb.*.numa_stat file, > which shows the numa information of the cgroup similarly to > memory.numa_stat. > > On cgroup-v2: > cat /sys/fs/cgroup/unified/test/hugetlb.2MB.numa_stat > total=3D2097152 N0=3D2097152 N1=3D0 > > On cgroup-v1: > cat /sys/fs/cgroup/hugetlb/test/hugetlb.2MB.numa_stat > total=3D2097152 N0=3D2097152 N1=3D0 > hierarichal_total=3D2097152 N0=3D2097152 N1=3D0 > > This patch was tested manually by allocating hugetlb memory and querying > the hugetlb.*.numa_stat file of the cgroup and its parents. > =EF=BF=BC > Cc: Mike Kravetz > Cc: Andrew Morton > Cc: Shuah Khan > Cc: Miaohe Lin > Cc: Oscar Salvador > Cc: Michal Hocko > Cc: Muchun Song > Cc: David Rientjes > Cc: Shakeel Butt > Cc: Jue Wang > Cc: Yang Yao > Cc: Joanna Li > Cc: Cannon Matthews > Cc: linux-mm@kvack.org > Cc: linux-kernel@vger.kernel.org > > Signed-off-by: Mina Almasry > > --- > > Changes in v6: > - Changed usage from unsigned long to atomic_long_t > > Changes in v5: > - Fixed commit message typo. > - Fixed per node usage documentation to be in pages. > - Removed unnecessary h_cg check. > > Changes in v4: > - Removed unnecessary braces. > - usage is now counted in pages instead of bytes. > - Reverted unneeded changes to write_to_hugetlbfs.c > > Changes in v3: > - Fixed typos (sorry!) > - Used conventional locations for cgroups mount points in docs/commit > message. > - Updated docs. > - Handle kzalloc_node failure, and proper deallocation of per node data. > - Use struct_size() to calculate the struct size. > - Use nr_node_ids instead of MAX_NUMNODES. > - Updated comments per multi-line comment pattern. > > Changes in v2: > - Fix warning Reported-by: kernel test robot > --- > .../admin-guide/cgroup-v1/hugetlb.rst | 4 + > Documentation/admin-guide/cgroup-v2.rst | 5 + > include/linux/hugetlb.h | 4 +- > include/linux/hugetlb_cgroup.h | 7 ++ > mm/hugetlb_cgroup.c | 118 ++++++++++++++++-- > 5 files changed, 127 insertions(+), 11 deletions(-) > > diff --git a/Documentation/admin-guide/cgroup-v1/hugetlb.rst b/Documentat= ion/admin-guide/cgroup-v1/hugetlb.rst > index 338f2c7d7a1c..0fa724d82abb 100644 > --- a/Documentation/admin-guide/cgroup-v1/hugetlb.rst > +++ b/Documentation/admin-guide/cgroup-v1/hugetlb.rst > @@ -29,12 +29,14 @@ Brief summary of control files:: > hugetlb..max_usage_in_bytes # show max "hugep= agesize" hugetlb usage recorded > hugetlb..usage_in_bytes # show current us= age for "hugepagesize" hugetlb > hugetlb..failcnt # show the number= of allocation failure due to HugeTLB usage limit > + hugetlb..numa_stat # show the numa i= nformation of the hugetlb memory charged to this cgroup > > For a system supporting three hugepage sizes (64k, 32M and 1G), the cont= rol > files include:: > > hugetlb.1GB.limit_in_bytes > hugetlb.1GB.max_usage_in_bytes > + hugetlb.1GB.numa_stat > hugetlb.1GB.usage_in_bytes > hugetlb.1GB.failcnt > hugetlb.1GB.rsvd.limit_in_bytes > @@ -43,6 +45,7 @@ files include:: > hugetlb.1GB.rsvd.failcnt > hugetlb.64KB.limit_in_bytes > hugetlb.64KB.max_usage_in_bytes > + hugetlb.64KB.numa_stat > hugetlb.64KB.usage_in_bytes > hugetlb.64KB.failcnt > hugetlb.64KB.rsvd.limit_in_bytes > @@ -51,6 +54,7 @@ files include:: > hugetlb.64KB.rsvd.failcnt > hugetlb.32MB.limit_in_bytes > hugetlb.32MB.max_usage_in_bytes > + hugetlb.32MB.numa_stat > hugetlb.32MB.usage_in_bytes > hugetlb.32MB.failcnt > hugetlb.32MB.rsvd.limit_in_bytes > diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admi= n-guide/cgroup-v2.rst > index 4d8c27eca96b..356847f8f008 100644 > --- a/Documentation/admin-guide/cgroup-v2.rst > +++ b/Documentation/admin-guide/cgroup-v2.rst > @@ -2252,6 +2252,11 @@ HugeTLB Interface Files > are local to the cgroup i.e. not hierarchical. The file modified = event > generated on this file reflects only the local events. > > + hugetlb..numa_stat > + Similar to memory.numa_stat, it shows the numa information of the > + hugetlb pages of in this cgroup. Only active in > + use hugetlb pages are included. The per-node values are in byte= s. > + > Misc > ---- > > diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h > index 1faebe1cd0ed..0445faaa636e 100644 > --- a/include/linux/hugetlb.h > +++ b/include/linux/hugetlb.h > @@ -613,8 +613,8 @@ struct hstate { > #endif > #ifdef CONFIG_CGROUP_HUGETLB > /* cgroup control files */ > - struct cftype cgroup_files_dfl[7]; > - struct cftype cgroup_files_legacy[9]; > + struct cftype cgroup_files_dfl[8]; > + struct cftype cgroup_files_legacy[10]; > #endif > char name[HSTATE_NAME_LEN]; > }; > diff --git a/include/linux/hugetlb_cgroup.h b/include/linux/hugetlb_cgrou= p.h > index c137396129db..13aa0210ff70 100644 > --- a/include/linux/hugetlb_cgroup.h > +++ b/include/linux/hugetlb_cgroup.h > @@ -36,6 +36,11 @@ enum hugetlb_memory_event { > HUGETLB_NR_MEMORY_EVENTS, > }; > > +struct hugetlb_cgroup_per_node { > + /* hugetlb usage in pages over all hstates. */ > + atomic_long_t usage[HUGE_MAX_HSTATE]; Why do you use atomic? IIUC, 'usage' is always increased/decreased under hugetlb_lock except hugetlb_cgroup_read_numa_stat() which is always reading it. So I think WRITE_ONCE/READ_ONCE is enough. Thanks. > +}; > + > struct hugetlb_cgroup { > struct cgroup_subsys_state css; > > @@ -57,6 +62,8 @@ struct hugetlb_cgroup { > > /* Handle for "hugetlb.events.local" */ > struct cgroup_file events_local_file[HUGE_MAX_HSTATE]; > + > + struct hugetlb_cgroup_per_node *nodeinfo[]; > }; > > static inline struct hugetlb_cgroup * > diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c > index 5383023d0cca..be1f25a9ba28 100644 > --- a/mm/hugetlb_cgroup.c > +++ b/mm/hugetlb_cgroup.c > @@ -126,29 +126,58 @@ static void hugetlb_cgroup_init(struct hugetlb_cgro= up *h_cgroup, > } > } > > +static void hugetlb_cgroup_free(struct hugetlb_cgroup *h_cgroup) > +{ > + int node; > + > + for_each_node(node) > + kfree(h_cgroup->nodeinfo[node]); > + kfree(h_cgroup); > +} > + > static struct cgroup_subsys_state * > hugetlb_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) > { > struct hugetlb_cgroup *parent_h_cgroup =3D hugetlb_cgroup_from_cs= s(parent_css); > struct hugetlb_cgroup *h_cgroup; > + int node; > + > + h_cgroup =3D kzalloc(struct_size(h_cgroup, nodeinfo, nr_node_ids)= , > + GFP_KERNEL); > > - h_cgroup =3D kzalloc(sizeof(*h_cgroup), GFP_KERNEL); > if (!h_cgroup) > return ERR_PTR(-ENOMEM); > > if (!parent_h_cgroup) > root_h_cgroup =3D h_cgroup; > > + /* > + * TODO: this routine can waste much memory for nodes which will > + * never be onlined. It's better to use memory hotplug callback > + * function. > + */ > + for_each_node(node) { > + /* Set node_to_alloc to -1 for offline nodes. */ > + int node_to_alloc =3D > + node_state(node, N_NORMAL_MEMORY) ? node : -1; > + h_cgroup->nodeinfo[node] =3D > + kzalloc_node(sizeof(struct hugetlb_cgroup_per_nod= e), > + GFP_KERNEL, node_to_alloc); > + if (!h_cgroup->nodeinfo[node]) > + goto fail_alloc_nodeinfo; > + } > + > hugetlb_cgroup_init(h_cgroup, parent_h_cgroup); > return &h_cgroup->css; > + > +fail_alloc_nodeinfo: > + hugetlb_cgroup_free(h_cgroup); > + return ERR_PTR(-ENOMEM); > } > > static void hugetlb_cgroup_css_free(struct cgroup_subsys_state *css) > { > - struct hugetlb_cgroup *h_cgroup; > - > - h_cgroup =3D hugetlb_cgroup_from_css(css); > - kfree(h_cgroup); > + hugetlb_cgroup_free(hugetlb_cgroup_from_css(css)); > } > > /* > @@ -292,7 +321,9 @@ static void __hugetlb_cgroup_commit_charge(int idx, u= nsigned long nr_pages, > return; > > __set_hugetlb_cgroup(page, h_cg, rsvd); > - return; > + if (!rsvd) > + atomic_long_add(nr_pages, > + &h_cg->nodeinfo[page_to_nid(page)]->usage= [idx]); > } > > void hugetlb_cgroup_commit_charge(int idx, unsigned long nr_pages, > @@ -331,7 +362,9 @@ static void __hugetlb_cgroup_uncharge_page(int idx, u= nsigned long nr_pages, > > if (rsvd) > css_put(&h_cg->css); > - > + else > + atomic_long_sub(nr_pages, > + &h_cg->nodeinfo[page_to_nid(page)]->usage= [idx]); > return; Could you remove "return" by the way? > } > > @@ -421,6 +454,61 @@ enum { > RES_RSVD_FAILCNT, > }; > > +static int hugetlb_cgroup_read_numa_stat(struct seq_file *seq, void *dum= my) > +{ > + int nid; > + struct cftype *cft =3D seq_cft(seq); > + int idx =3D MEMFILE_IDX(cft->private); > + bool legacy =3D MEMFILE_ATTR(cft->private); > + struct hugetlb_cgroup *h_cg =3D hugetlb_cgroup_from_css(seq_css(s= eq)); > + struct cgroup_subsys_state *css; > + unsigned long usage; > + > + if (legacy) { > + /* Add up usage across all nodes for the non-hierarchical= total. */ > + usage =3D 0; > + for_each_node_state(nid, N_MEMORY) > + usage +=3D atomic_long_read( > + &h_cg->nodeinfo[nid]->usage[idx]); > + seq_printf(seq, "total=3D%lu", usage * PAGE_SIZE); > + > + /* Simply print the per-node usage for the non-hierarchic= al total. */ > + for_each_node_state(nid, N_MEMORY) > + seq_printf(seq, " N%d=3D%lu", nid, > + atomic_long_read( > + &h_cg->nodeinfo[nid]->usage[id= x]) * > + PAGE_SIZE); > + seq_putc(seq, '\n'); > + } > + > + /* > + * The hierarchical total is pretty much the value recorded by th= e > + * counter, so use that. > + */ > + seq_printf(seq, "%stotal=3D%lu", legacy ? "hierarichal_" : "", > + page_counter_read(&h_cg->hugepage[idx]) * PAGE_SIZE); > + > + /* > + * For each node, transverse the css tree to obtain the hierarich= al > + * node usage. > + */ > + for_each_node_state(nid, N_MEMORY) { > + usage =3D 0; > + rcu_read_lock(); > + css_for_each_descendant_pre(css, &h_cg->css) { > + usage +=3D atomic_long_read(&hugetlb_cgroup_from_= css(css) > + ->nodeinfo[nid= ] > + ->usage[idx]); > + } > + rcu_read_unlock(); > + seq_printf(seq, " N%d=3D%lu", nid, usage * PAGE_SIZE); > + } > + > + seq_putc(seq, '\n'); > + > + return 0; > +} > + > static u64 hugetlb_cgroup_read_u64(struct cgroup_subsys_state *css, > struct cftype *cft) > { > @@ -671,8 +759,14 @@ static void __init __hugetlb_cgroup_file_dfl_init(in= t idx) > events_local_file[idx]); > cft->flags =3D CFTYPE_NOT_ON_ROOT; > > - /* NULL terminate the last cft */ > + /* Add the numa stat file */ > cft =3D &h->cgroup_files_dfl[6]; > + snprintf(cft->name, MAX_CFTYPE_NAME, "%s.numa_stat", buf); > + cft->seq_show =3D hugetlb_cgroup_read_numa_stat; > + cft->flags =3D CFTYPE_NOT_ON_ROOT; > + > + /* NULL terminate the last cft */ > + cft =3D &h->cgroup_files_dfl[7]; > memset(cft, 0, sizeof(*cft)); > > WARN_ON(cgroup_add_dfl_cftypes(&hugetlb_cgrp_subsys, > @@ -742,8 +836,14 @@ static void __init __hugetlb_cgroup_file_legacy_init= (int idx) > cft->write =3D hugetlb_cgroup_reset; > cft->read_u64 =3D hugetlb_cgroup_read_u64; > > + /* Add the numa stat file */ > + cft =3D &h->cgroup_files_dfl[8]; > + snprintf(cft->name, MAX_CFTYPE_NAME, "%s.numa_stat", buf); > + cft->private =3D MEMFILE_PRIVATE(idx, 1); > + cft->seq_show =3D hugetlb_cgroup_read_numa_stat; > + > /* NULL terminate the last cft */ > - cft =3D &h->cgroup_files_legacy[8]; > + cft =3D &h->cgroup_files_legacy[9]; > memset(cft, 0, sizeof(*cft)); > > WARN_ON(cgroup_add_legacy_cftypes(&hugetlb_cgrp_subsys, > -- > 2.34.0.rc0.344.g81b53c2807-goog