Messages in this thread | | | Date | Tue, 21 Nov 2017 11:19:07 -0800 | From | Andrew Morton <> | Subject | Re: [PATCH v2] mm: show total hugetlb memory consumption in /proc/meminfo |
| |
On Tue, 21 Nov 2017 15:15:55 +0000 Roman Gushchin <guro@fb.com> wrote:
> > > + > > > + for_each_hstate(h) { > > > + unsigned long count = h->nr_huge_pages; > > > + > > > + total += (PAGE_SIZE << huge_page_order(h)) * count; > > > + > > > + if (h == &default_hstate) > > > > I'm not understanding this test. Are we assuming that default_hstate > > always refers to the highest-index hstate? If so why, and is that > > valid? > > As Mike and Michal pointed, default_hstate is defined as > #define default_hstate (hstates[default_hstate_idx]), > where default_hstate_idx can be altered by a boot argument. > > We're iterating over all states to calculate total and also > print some additional info for the default size. Having a single > loop guarantees consistency of these numbers. >
OK, I misread the handling of `count' -> HugePages_Total.
It seems unnecessarily obscure?
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);
Why not
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) total += (PAGE_SIZE << huge_page_order(h)) * h->nr_huge_pages; seq_printf(m, "Hugetlb: %8lu kB\n", total / 1024); ?
| |