From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754414AbbIIPMR (ORCPT ); Wed, 9 Sep 2015 11:12:17 -0400 Received: from mx2.suse.de ([195.135.220.15]:39727 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754129AbbIIPMN (ORCPT ); Wed, 9 Sep 2015 11:12:13 -0400 Subject: Re: [PATCH v5 1/2] mm: hugetlb: proc: add HugetlbPages field to /proc/PID/smaps To: Naoya Horiguchi , Andrew Morton References: <20150812000336.GB32192@hori1.linux.bs1.fc.nec.co.jp> <1440059182-19798-1-git-send-email-n-horiguchi@ah.jp.nec.com> <1440059182-19798-2-git-send-email-n-horiguchi@ah.jp.nec.com> Cc: David Rientjes , =?UTF-8?Q?J=c3=b6rn_Engel?= , Mike Kravetz , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , Naoya Horiguchi From: Vlastimil Babka Message-ID: <55F04C48.7070105@suse.cz> Date: Wed, 9 Sep 2015 17:12:08 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 MIME-Version: 1.0 In-Reply-To: <1440059182-19798-2-git-send-email-n-horiguchi@ah.jp.nec.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/20/2015 10:26 AM, Naoya Horiguchi wrote: > Currently /proc/PID/smaps provides no usage info for vma(VM_HUGETLB), which > is inconvenient when we want to know per-task or per-vma base hugetlb usage. > To solve this, this patch adds a new line for hugetlb usage like below: > > Size: 20480 kB > Rss: 0 kB > Pss: 0 kB > Shared_Clean: 0 kB > Shared_Dirty: 0 kB > Private_Clean: 0 kB > Private_Dirty: 0 kB > Referenced: 0 kB > Anonymous: 0 kB > AnonHugePages: 0 kB > HugetlbPages: 18432 kB > Swap: 0 kB > KernelPageSize: 2048 kB > MMUPageSize: 2048 kB > Locked: 0 kB > VmFlags: rd wr mr mw me de ht > > Signed-off-by: Naoya Horiguchi > Acked-by: Joern Engel > Acked-by: David Rientjes Sorry for coming late to this thread. It's a nice improvement, but I find it somewhat illogical that the per-process stats (status) are more detailed than the per-mapping stats (smaps) with respect to the size breakdown. I would expect it to be the other way around. That would simplify the per-process accounting (I realize this has been a hot topic already), and allow those who really care to look at smaps. I'm just not sure about the format in that case. In smaps, a line per size would probably make more sense. Even in status, the extra information in parentheses looks somewhat out of place. But of course, adding shared/private breakdown as suggested would lead to an explosion of number of lines in that case... > --- > v3 -> v4: > - suspend Acked-by tag because v3->v4 change is not trivial > - I stated in previous discussion that HugetlbPages line can contain page > size info, but that's not necessary because we already have KernelPageSize > info. > - merged documentation update, where the current documentation doesn't mention > AnonHugePages, so it's also added. > --- > Documentation/filesystems/proc.txt | 7 +++++-- > fs/proc/task_mmu.c | 29 +++++++++++++++++++++++++++++ > 2 files changed, 34 insertions(+), 2 deletions(-) > > diff --git v4.2-rc4/Documentation/filesystems/proc.txt v4.2-rc4_patched/Documentation/filesystems/proc.txt > index 6f7fafde0884..22e40211ef64 100644 > --- v4.2-rc4/Documentation/filesystems/proc.txt > +++ v4.2-rc4_patched/Documentation/filesystems/proc.txt > @@ -423,6 +423,8 @@ Private_Clean: 0 kB > Private_Dirty: 0 kB > Referenced: 892 kB > Anonymous: 0 kB > +AnonHugePages: 0 kB > +HugetlbPages: 0 kB > Swap: 0 kB > KernelPageSize: 4 kB > MMUPageSize: 4 kB > @@ -440,8 +442,9 @@ indicates the amount of memory currently marked as referenced or accessed. > "Anonymous" shows the amount of memory that does not belong to any file. Even > a mapping associated with a file may contain anonymous pages: when MAP_PRIVATE > and a page is modified, the file page is replaced by a private anonymous copy. > -"Swap" shows how much would-be-anonymous memory is also used, but out on > -swap. > +"AnonHugePages" shows the ammount of memory backed by transparent hugepage. > +"HugetlbPages" shows the ammount of memory backed by hugetlbfs page. > +"Swap" shows how much would-be-anonymous memory is also used, but out on swap. > > "VmFlags" field deserves a separate description. This member represents the kernel > flags associated with the particular virtual memory area in two letter encoded > diff --git v4.2-rc4/fs/proc/task_mmu.c v4.2-rc4_patched/fs/proc/task_mmu.c > index ca1e091881d4..2c37938b82ee 100644 > --- v4.2-rc4/fs/proc/task_mmu.c > +++ v4.2-rc4_patched/fs/proc/task_mmu.c > @@ -445,6 +445,7 @@ struct mem_size_stats { > unsigned long anonymous; > unsigned long anonymous_thp; > unsigned long swap; > + unsigned long hugetlb; > u64 pss; > }; > > @@ -610,12 +611,38 @@ static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma) > seq_putc(m, '\n'); > } > > +#ifdef CONFIG_HUGETLB_PAGE > +static int smaps_hugetlb_range(pte_t *pte, unsigned long hmask, > + unsigned long addr, unsigned long end, > + struct mm_walk *walk) > +{ > + struct mem_size_stats *mss = walk->private; > + struct vm_area_struct *vma = walk->vma; > + struct page *page = NULL; > + > + if (pte_present(*pte)) { > + page = vm_normal_page(vma, addr, *pte); > + } else if (is_swap_pte(*pte)) { > + swp_entry_t swpent = pte_to_swp_entry(*pte); > + > + if (is_migration_entry(swpent)) > + page = migration_entry_to_page(swpent); > + } > + if (page) > + mss->hugetlb += huge_page_size(hstate_vma(vma)); > + return 0; > +} > +#endif /* HUGETLB_PAGE */ > + > static int show_smap(struct seq_file *m, void *v, int is_pid) > { > struct vm_area_struct *vma = v; > struct mem_size_stats mss; > struct mm_walk smaps_walk = { > .pmd_entry = smaps_pte_range, > +#ifdef CONFIG_HUGETLB_PAGE > + .hugetlb_entry = smaps_hugetlb_range, > +#endif > .mm = vma->vm_mm, > .private = &mss, > }; > @@ -637,6 +664,7 @@ static int show_smap(struct seq_file *m, void *v, int is_pid) > "Referenced: %8lu kB\n" > "Anonymous: %8lu kB\n" > "AnonHugePages: %8lu kB\n" > + "HugetlbPages: %8lu kB\n" > "Swap: %8lu kB\n" > "KernelPageSize: %8lu kB\n" > "MMUPageSize: %8lu kB\n" > @@ -651,6 +679,7 @@ static int show_smap(struct seq_file *m, void *v, int is_pid) > mss.referenced >> 10, > mss.anonymous >> 10, > mss.anonymous_thp >> 10, > + mss.hugetlb >> 10, > mss.swap >> 10, > vma_kernel_pagesize(vma) >> 10, > vma_mmu_pagesize(vma) >> 10, >