Hi Andrew, > On 8/10/2022 2:49 PM, Yin Fengwei wrote: Sorry for pinging you here. I suppose all the review comments were addressed so far. To make this patch merged, any other action I need to take? Thanks. v1 is on: https://lore.kernel.org/linux-mm/20220804025121.4001361-1-fengwei.yin@xxxxxxxxx/ v2 is on: https://lore.kernel.org/linux-mm/20220805062844.439152-1-fengwei.yin@xxxxxxxxx/ v3 is on: https://lore.kernel.org/linux-mm/20220810064907.582899-1-fengwei.yin@xxxxxxxxx/ Regards Yin, Fengwei > If there is private data attached to THP, the refcount of > THP will be increased and block the THP split. Release > private data attached to THP before split it to increase > the chance of splitting THP successfully. > > There was a memory failure issue hit during HW error > injection testing with 5.18 kernel + xfs as rootfs. Test > got killed and system reboot was required to re-run the > test. > > The issue was tracked down to THP split failure caused the > memory failure not being handled. The page dump showed: > > [ 1785.433075] page:0000000025f9530b refcount:18 mapcount:0 mapping:000000008162eea7 index:0xa10 pfn:0x2f0200 > [ 1785.443954] head:0000000025f9530b order:4 compound_mapcount:0 compound_pincount:0 > [ 1785.452408] memcg:ff4247f2d28e9000 > [ 1785.456304] aops:xfs_address_space_operations ino:8555182 dentry name:"baseos-filenames.solvx" > [ 1785.466612] flags: 0x1000000000012036(referenced|uptodate|lru|active|private|head|node=0|zone=2) > [ 1785.476514] raw: 1000000000012036 ffb9460f8bc07c08 ffb9460f8bc08408 ff4247f22e6299f8 > [ 1785.485268] raw: 0000000000000a10 ff4247f194ade900 00000012ffffffff ff4247f2d28e9000 > > It was like the error was injected to a large folio for xfs > with private data attached. > > With private data released before split THP, the test case > could be run successfully many times without reboot system. > > Co-developed-by: Qiuxu Zhuo <qiuxu.zhuo@xxxxxxxxx> > Signed-off-by: Qiuxu Zhuo <qiuxu.zhuo@xxxxxxxxx> > Signed-off-by: Yin Fengwei <fengwei.yin@xxxxxxxxx> > Suggested-by: Matthew Wilcox <willy@xxxxxxxxxxxxx> > --- > Changelog from v2: > - Use safe gfp flags for different callsite of split_huge_page_to_list > per Yang's comment. > - Remove reviewed-by tag from Aaron which was only valid for RFC patch > but keep it by mistake. > > Changelog from v1: > - Move private release to split_huge_page_to_list > to cover wider path per Yang's comment. > - Update to commit message. > > Changelog from RFC: > - Use new folio API per Mathhew Wilcox's suggestion. > - Add one line comment before re-get folio of page per > Miaohe's comment. > - Remove RFC tag > - Add Co-developed-by of Qiuxu who did a lot of debugging > work to locate where the real issue is. > mm/huge_memory.c | 14 ++++++++++++-- > 1 file changed, 12 insertions(+), 2 deletions(-) > > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > index 8a7c1b344abe..ae8c4e209e58 100644 > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -2627,6 +2627,8 @@ int split_huge_page_to_list(struct page *page, struct list_head *list) > mapping = NULL; > anon_vma_lock_write(anon_vma); > } else { > + gfp_t gfp; > + > mapping = head->mapping; > > /* Truncated ? */ > @@ -2635,8 +2637,16 @@ int split_huge_page_to_list(struct page *page, struct list_head *list) > goto out; > } > > - xas_split_alloc(&xas, head, compound_order(head), > - mapping_gfp_mask(mapping) & GFP_RECLAIM_MASK); > + gfp = current_gfp_context(mapping_gfp_mask(mapping) & > + GFP_RECLAIM_MASK); > + > + if (folio_test_private(folio) && > + !filemap_release_folio(folio, gfp)) { > + ret = -EBUSY; > + goto out; > + } > + > + xas_split_alloc(&xas, head, compound_order(head), gfp); > if (xas_error(&xas)) { > ret = xas_error(&xas); > goto out; > > base-commit: d4252071b97d2027d246f6a82cbee4d52f618b47
