Messages in this thread | | | Subject | Re: [PATCH 3/3] hugetlbfs: remove unnecessary code after i_mmap_rwsem synchronization | From | "Aneesh Kumar K.V" <> | Date | Mon, 17 Dec 2018 16:04:15 +0530 |
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On 12/4/18 1:38 AM, Mike Kravetz wrote: > After expanding i_mmap_rwsem use for better shared pmd and page fault/ > truncation synchronization, remove code that is no longer necessary. > > Cc: <stable@vger.kernel.org> > Fixes: ebed4bfc8da8 ("hugetlb: fix absurd HugePages_Rsvd") > Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> > --- > fs/hugetlbfs/inode.c | 46 +++++++++++++++----------------------------- > mm/hugetlb.c | 21 ++++++++++---------- > 2 files changed, 25 insertions(+), 42 deletions(-) > > diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c > index 3244147fc42b..a9c00c6ef80d 100644 > --- a/fs/hugetlbfs/inode.c > +++ b/fs/hugetlbfs/inode.c > @@ -383,17 +383,16 @@ hugetlb_vmdelete_list(struct rb_root_cached *root, pgoff_t start, pgoff_t end) > * truncation is indicated by end of range being LLONG_MAX > * In this case, we first scan the range and release found pages. > * After releasing pages, hugetlb_unreserve_pages cleans up region/reserv > - * maps and global counts. Page faults can not race with truncation > - * in this routine. hugetlb_no_page() prevents page faults in the > - * truncated range. It checks i_size before allocation, and again after > - * with the page table lock for the page held. The same lock must be > - * acquired to unmap a page. > + * maps and global counts. > * hole punch is indicated if end is not LLONG_MAX > * In the hole punch case we scan the range and release found pages. > * Only when releasing a page is the associated region/reserv map > * deleted. The region/reserv map for ranges without associated > - * pages are not modified. Page faults can race with hole punch. > - * This is indicated if we find a mapped page. > + * pages are not modified. > + * > + * Callers of this routine must hold the i_mmap_rwsem in write mode to prevent > + * races with page faults.
Should this patch be merged to the previous one? Because the changes to callers are done in the previous patch.
> + * > * Note: If the passed end of range value is beyond the end of file, but > * not LLONG_MAX this routine still performs a hole punch operation. > */ > @@ -423,32 +422,14 @@ static void remove_inode_hugepages(struct inode *inode, loff_t lstart, > > for (i = 0; i < pagevec_count(&pvec); ++i) { > -aneesh
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