On Wed 15-11-17 23:14:09, Roman Gushchin wrote: > Currently we display some hugepage statistics (total, free, etc) > in /proc/meminfo, but only for default hugepage size (e.g. 2Mb). > > If hugepages of different sizes are used (like 2Mb and 1Gb on x86-64), > /proc/meminfo output can be confusing, as non-default sized hugepages > are not reflected at all, and there are no signs that they are > existing and consuming system memory. > > To solve this problem, let's display the total amount of memory, > consumed by hugetlb pages of all sized (both free and used). > Let's call it "Hugetlb", and display size in kB to match generic > /proc/meminfo style. > > For example, (1024 2Mb pages and 2 1Gb pages are pre-allocated): > $ cat /proc/meminfo > MemTotal: 8168984 kB > MemFree: 3789276 kB > <...> > CmaFree: 0 kB > HugePages_Total: 1024 > HugePages_Free: 1024 > HugePages_Rsvd: 0 > HugePages_Surp: 0 > Hugepagesize: 2048 kB > Hugetlb: 4194304 kB > DirectMap4k: 32632 kB > DirectMap2M: 4161536 kB > DirectMap1G: 6291456 kB > > Also, this patch updates corresponding docs to reflect > Hugetlb entry meaning and difference between Hugetlb and > HugePages_Total * Hugepagesize. > > Signed-off-by: Roman Gushchin <[email protected]> > Cc: Andrew Morton <[email protected]> > Cc: Michal Hocko <[email protected]> > Cc: Johannes Weiner <[email protected]> > Cc: Mike Kravetz <[email protected]> > Cc: "Aneesh Kumar K.V" <[email protected]> > Cc: Andrea Arcangeli <[email protected]> > Cc: Dave Hansen <[email protected]> > Cc: David Rientjes <[email protected]> > Cc: [email protected] > Cc: [email protected] > Cc: [email protected]
Acked-by: Michal Hocko <[email protected]> Thanks! > --- > Documentation/vm/hugetlbpage.txt | 27 ++++++++++++++++++--------- > mm/hugetlb.c | 36 ++++++++++++++++++++++++------------ > 2 files changed, 42 insertions(+), 21 deletions(-) > > diff --git a/Documentation/vm/hugetlbpage.txt > b/Documentation/vm/hugetlbpage.txt > index 59cbc803aad6..faf077d50d42 100644 > --- a/Documentation/vm/hugetlbpage.txt > +++ b/Documentation/vm/hugetlbpage.txt > @@ -20,19 +20,20 @@ options. > > The /proc/meminfo file provides information about the total number of > persistent hugetlb pages in the kernel's huge page pool. It also displays > -information about the number of free, reserved and surplus huge pages and the > -default huge page size. The huge page size is needed for generating the > -proper alignment and size of the arguments to system calls that map huge page > -regions. > +default huge page size and information about the number of free, reserved > +and surplus huge pages in the pool of huge pages of default size. > +The huge page size is needed for generating the proper alignment and > +size of the arguments to system calls that map huge page regions. > > The output of "cat /proc/meminfo" will include lines like: > > ..... > -HugePages_Total: vvv > -HugePages_Free: www > -HugePages_Rsvd: xxx > -HugePages_Surp: yyy > -Hugepagesize: zzz kB > +HugePages_Total: uuu > +HugePages_Free: vvv > +HugePages_Rsvd: www > +HugePages_Surp: xxx > +Hugepagesize: yyy kB > +Hugetlb: zzz kB > > where: > HugePages_Total is the size of the pool of huge pages. > @@ -47,6 +48,14 @@ HugePages_Surp is short for "surplus," and is the number > of huge pages in > the pool above the value in /proc/sys/vm/nr_hugepages. The > maximum number of surplus huge pages is controlled by > /proc/sys/vm/nr_overcommit_hugepages. > +Hugepagesize is the default hugepage size (in Kb). > +Hugetlb is the total amount of memory (in kB), consumed by huge > + pages of all sizes. > + If huge pages of different sizes are in use, this number > + will exceed HugePages_Total * Hugepagesize. To get more > + detailed information, please, refer to > + /sys/kernel/mm/hugepages (described below). > + > > /proc/filesystems should also show a filesystem of type "hugetlbfs" > configured > in the kernel. > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > index 4b3bbd2980bb..672377e6de9f 100644 > --- a/mm/hugetlb.c > +++ b/mm/hugetlb.c > @@ -2973,20 +2973,32 @@ int hugetlb_overcommit_handler(struct ctl_table > *table, int write, > > void hugetlb_report_meminfo(struct seq_file *m) > { > - struct hstate *h = &default_hstate; > + struct hstate *h; > + unsigned long total = 0; > + > if (!hugepages_supported()) > return; > - seq_printf(m, > - "HugePages_Total: %5lu\n" > - "HugePages_Free: %5lu\n" > - "HugePages_Rsvd: %5lu\n" > - "HugePages_Surp: %5lu\n" > - "Hugepagesize: %8lu kB\n", > - h->nr_huge_pages, > - h->free_huge_pages, > - h->resv_huge_pages, > - h->surplus_huge_pages, > - 1UL << (huge_page_order(h) + PAGE_SHIFT - 10)); > + > + for_each_hstate(h) { > + unsigned long count = h->nr_huge_pages; > + > + total += (PAGE_SIZE << huge_page_order(h)) * count; > + > + if (h == &default_hstate) > + seq_printf(m, > + "HugePages_Total: %5lu\n" > + "HugePages_Free: %5lu\n" > + "HugePages_Rsvd: %5lu\n" > + "HugePages_Surp: %5lu\n" > + "Hugepagesize: %8lu kB\n", > + count, > + h->free_huge_pages, > + h->resv_huge_pages, > + h->surplus_huge_pages, > + (PAGE_SIZE << huge_page_order(h)) / 1024); > + } > + > + seq_printf(m, "Hugetlb: %8lu kB\n", total / 1024); > } > > int hugetlb_report_node_meminfo(int nid, char *buf) > -- > 2.13.6 > -- Michal Hocko SUSE Labs
