On Tue, Aug 04, 2015 at 05:13:39AM +0000, Naoya Horiguchi wrote: > On Tue, Aug 04, 2015 at 02:55:30AM +0000, Naoya Horiguchi wrote: > > > > One possible way to get hugetlb metric in per-task basis is to walk page > > table via /proc/pid/pagemap, and counting page flags for each mapped page > > (we can easily do this with tools/vm/page-types.c like "page-types -p <PID> > > -b huge"). This is obviously slower than just storing the counter as > > in-kernel data and just exporting it, but might be useful in some situation.
Maybe. The current situation is a mess and I don't know the best way out of it yet. > BTW, currently smaps doesn't report any meaningful info for vma(VM_HUGETLB). > I wrote the following patch, which hopefully is helpful for your purpose. > > Thanks, > Naoya Horiguchi > > --- > From: Naoya Horiguchi <[email protected]> > Subject: [PATCH] smaps: fill missing fields for vma(VM_HUGETLB) > > Currently smaps reports many zero fields for vma(VM_HUGETLB), which is > inconvenient when we want to know per-task or per-vma base hugetlb usage. > This patch enables these fields by introducing smaps_hugetlb_range(). > > before patch: > > 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 > Swap: 0 kB > KernelPageSize: 2048 kB > MMUPageSize: 2048 kB > Locked: 0 kB > VmFlags: rd wr mr mw me de ht > > after patch: > > Size: 20480 kB > Rss: 18432 kB > Pss: 18432 kB > Shared_Clean: 0 kB > Shared_Dirty: 0 kB > Private_Clean: 0 kB > Private_Dirty: 18432 kB > Referenced: 18432 kB > Anonymous: 18432 kB > AnonHugePages: 0 kB > Swap: 0 kB > KernelPageSize: 2048 kB > MMUPageSize: 2048 kB > Locked: 0 kB > VmFlags: rd wr mr mw me de ht Nice! > Signed-off-by: Naoya Horiguchi <[email protected]> > --- > fs/proc/task_mmu.c | 27 +++++++++++++++++++++++++++ > 1 file changed, 27 insertions(+) > > diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c > index ca1e091881d4..c7218603306d 100644 > --- a/fs/proc/task_mmu.c > +++ b/fs/proc/task_mmu.c > @@ -610,12 +610,39 @@ 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) > + smaps_account(mss, page, huge_page_size(hstate_vma(vma)), > + pte_young(*pte), pte_dirty(*pte)); > + 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 Not too fond of the #ifdef. But I won't blame you, as there already is an example of the same and - worse - a contradicting example that unconditionally assigns and moved the #ifdef elsewhere. Hugetlb is the unloved stepchild with 13 years of neglect and half-measures. It shows. Patch looks good to me. Acked-by: Jörn Engel <[email protected]> Jörn -- Functionality is an asset, but code is a liability. --Ted Dziuba -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
