This patch set has gone through several revisions as an RFC which is documented in the log below. The major change in this version is the addition of code to handle the region_chg/region_add calling sequence with the addition of fallocate hole punch. This is the first patch in the series. As suggested during the RFC process, tests have been proposed to libhugetlbfs as described at: http://librelist.com/browser//libhugetlbfs/2015/6/25/patch-tests-add-tests-for-fallocate-system-call/ fallocate(2) man page modifications are also necessary to specify that fallocate for hugetlbfs only operates on whole pages. This change will be submitted once the code has stabalized and been proposed for merging. hugetlbfs is used today by applications that want a high degree of control over huge page usage. Often, large hugetlbfs files are used to map a large number huge pages into the application processes. The applications know when page ranges within these large files will no longer be used, and ideally would like to release them back to the subpool or global pools for other uses. The fallocate() system call provides an interface for preallocation and hole punching within files. This patch set adds fallocate functionality to hugetlbfs. v1: Add a cache of region descriptors to the resv_map for use by region_add in case hole punch deletes entries necessary for a successful operation. RFC v4: Removed alloc_huge_page/hugetlb_reserve_pages race patches as already in mmotm Moved hugetlb_fix_reserve_counts in series as suggested by Naoya Horiguchi Inline'ed hugetlb_fault_mutex routines as suggested by Davidlohr Bueso and existing code changed to use new interfaces as suggested by Naoya fallocate preallocation code cleaned up and made simpler Modified alloc_huge_page to handle special case where allocation is for a hole punched area with spool reserves RFC v3: Folded in patch for alloc_huge_page/hugetlb_reserve_pages race in current code fallocate allocation and hole punch is synchronized with page faults via existing mutex table hole punch uses existing hugetlb_vmtruncate_list instead of more generic unmap_mapping_range for unmapping Error handling for the case when region_del() fauils RFC v2: Addressed alignment and error handling issues noticed by Hillf Danton New region_del() routine for region tracking/resv_map of ranges Fixed several issues found during more extensive testing Error handling in region_del() when kmalloc() fails stills needs to be addressed madvise remove support remains Mike Kravetz (10): mm/hugetlb: add cache of descriptors to resv_map for region_add mm/hugetlb: add region_del() to delete a specific range of entries mm/hugetlb: expose hugetlb fault mutex for use by fallocate hugetlbfs: hugetlb_vmtruncate_list() needs to take a range to delete hugetlbfs: truncate_hugepages() takes a range of pages mm/hugetlb: vma_has_reserves() needs to handle fallocate hole punch mm/hugetlb: alloc_huge_page handle areas hole punched by fallocate hugetlbfs: New huge_add_to_page_cache helper routine hugetlbfs: add hugetlbfs_fallocate() mm: madvise allow remove operation for hugetlbfs fs/hugetlbfs/inode.c | 281 +++++++++++++++++++++++++++++--- include/linux/hugetlb.h | 17 +- mm/hugetlb.c | 422 ++++++++++++++++++++++++++++++++++++++---------- mm/madvise.c | 2 +- 4 files changed, 618 insertions(+), 104 deletions(-) -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
