On Thu 14-03-13 19:30:46, Wanpeng Li wrote: > Changelog: > v2 -> v3: > * update patch description, spotted by Michal > v1 -> v2: > * update patch description, spotted by Michal > > "hugetlb_total_pages is used for overcommit calculations but the > current implementation considers only default hugetlb page size (which > is either the first defined hugepage size or the one specified by > default_hugepagesz kernel boot parameter). > > If the system is configured for more than one hugepage size (which is > possible since a137e1cc hugetlbfs: per mount huge page sizes) then > the overcommit estimation done by __vm_enough_memory (resp. shown by > meminfo_proc_show) is not precise - there is an impression of more > available/allowed memory. This can lead to an unexpected ENOMEM/EFAULT > resp. SIGSEGV when memory is accounted."
Any reason for keeping the quotes I put in the previous email just to show what changelog I had in mind? > The patch should also push to 2.6.27 stable tree. There are no such trees, I have mentioned that only to point out which kernels are affected. > > Testcase: > boot: hugepagesz=1G hugepages=1 > the default overcommit ratio is 50 > before patch: > egrep 'CommitLimit' /proc/meminfo > CommitLimit: 55434168 kB > after patch: > egrep 'CommitLimit' /proc/meminfo > CommitLimit: 54909880 kB > Is this information useful at all? Cc: <[email protected]> # 3.0+ please > Signed-off-by: Wanpeng Li <[email protected]> Acked-by: Michal Hocko <[email protected]> > --- > mm/hugetlb.c | 7 +++++-- > 1 file changed, 5 insertions(+), 2 deletions(-) > > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > index cdb64e4..9e25040 100644 > --- a/mm/hugetlb.c > +++ b/mm/hugetlb.c > @@ -2124,8 +2124,11 @@ int hugetlb_report_node_meminfo(int nid, char *buf) > /* Return the number pages of memory we physically have, in PAGE_SIZE units. > */ > unsigned long hugetlb_total_pages(void) > { > - struct hstate *h = &default_hstate; > - return h->nr_huge_pages * pages_per_huge_page(h); > + struct hstate *h; > + unsigned long nr_total_pages = 0; > + for_each_hstate(h) > + nr_total_pages += h->nr_huge_pages * pages_per_huge_page(h); > + return nr_total_pages; > } > > static int hugetlb_acct_memory(struct hstate *h, long delta) > -- > 1.7.11.7 > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to [email protected]. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: <a href=mailto:"[email protected]";> [email protected] </a> -- Michal Hocko SUSE Labs -- 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/
