The patch titled Subject: mm/hugetlb: optimize minimum size (min_size) accounting has been added to the -mm tree. Its filename is mm-hugetlb-optimize-minimum-size-min_size-accounting.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/mm-hugetlb-optimize-minimum-size-min_size-accounting.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/mm-hugetlb-optimize-minimum-size-min_size-accounting.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Mike Kravetz <mike.kravetz@xxxxxxxxxx> Subject: mm/hugetlb: optimize minimum size (min_size) accounting It was observed that minimum size accounting associated with the hugetlbfs min_size mount option may not perform optimally and as expected. As huge pages/reservations are released from the filesystem and given back to the global pools, they are reserved for subsequent filesystem use as long as the subpool reserved count is less than subpool minimum size. It does not take into account used pages within the filesystem. The filesystem size limits are not exceeded and this is technically not a bug. However, better behavior would be to wait for the number of used pages/reservations associated with the filesystem to drop below the minimum size before taking reservations to satisfy minimum size. An optimization is also made to the hugepage_subpool_get_pages() routine which is called when pages/reservations are allocated. This does not change behavior, but simply avoids the accounting if all reservations have already been taken (subpool reserved count == 0). Signed-off-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx> Cc: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx> Cc: Hillf Danton <hillf.zj@xxxxxxxxxxxxxxx> Cc: David Rientjes <rientjes@xxxxxxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Cc: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx> Cc: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/hugetlb.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff -puN mm/hugetlb.c~mm-hugetlb-optimize-minimum-size-min_size-accounting mm/hugetlb.c --- a/mm/hugetlb.c~mm-hugetlb-optimize-minimum-size-min_size-accounting +++ a/mm/hugetlb.c @@ -144,7 +144,8 @@ static long hugepage_subpool_get_pages(s } } - if (spool->min_hpages != -1) { /* minimum size accounting */ + /* minimum size accounting */ + if (spool->min_hpages != -1 && spool->rsv_hpages) { if (delta > spool->rsv_hpages) { /* * Asking for more reserves than those already taken on @@ -182,7 +183,8 @@ static long hugepage_subpool_put_pages(s if (spool->max_hpages != -1) /* maximum size accounting */ spool->used_hpages -= delta; - if (spool->min_hpages != -1) { /* minimum size accounting */ + /* minimum size accounting */ + if (spool->min_hpages != -1 && spool->used_hpages < spool->min_hpages) { if (spool->rsv_hpages + delta <= spool->min_hpages) ret = 0; else _ Patches currently in -mm which might be from mike.kravetz@xxxxxxxxxx are mm-hugetlb-optimize-minimum-size-min_size-accounting.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html