From: Hugh Dickins hughd@google.com
mainline inclusion from mainline-v6.7-rc1 commit 054a9f7ccd0a60607fb9bbe1e06ca671494971bf category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/IAIHPC
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
--------------------------------
Extract shmem's memcg charging out of shmem_add_to_page_cache(): it's misleading done there, because many calls are dealing with a swapcache page, whose memcg is nowadays always remembered while swapped out, then the charge re-levied when it's brought back into swapcache.
Temporarily move it back up to the shmem_get_folio_gfp() level, where the memcg was charged before v5.8; but the next commit goes on to move it back down to a new home.
In making this change, it becomes clear that shmem_swapin_folio() does not need to know the vma, just the fault mm (if any): call it fault_mm rather than charge_mm - let mem_cgroup_charge() decide whom to charge.
Link: https://lkml.kernel.org/r/4b2143c5-bf32-64f0-841-81a81158dac@google.com Signed-off-by: Hugh Dickins hughd@google.com Reviewed-by: Jan Kara jack@suse.cz Cc: Axel Rasmussen axelrasmussen@google.com Cc: Carlos Maiolino cem@kernel.org Cc: Christian Brauner brauner@kernel.org Cc: Chuck Lever chuck.lever@oracle.com Cc: Darrick J. Wong djwong@kernel.org Cc: Dave Chinner dchinner@redhat.com Cc: Johannes Weiner hannes@cmpxchg.org Cc: Matthew Wilcox (Oracle) willy@infradead.org Cc: Tim Chen tim.c.chen@intel.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Liu Shixin liushixin2@huawei.com --- mm/shmem.c | 68 +++++++++++++++++++++++------------------------------- 1 file changed, 29 insertions(+), 39 deletions(-)
diff --git a/mm/shmem.c b/mm/shmem.c index a73386b1c2bf..8b5e78661443 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -147,9 +147,8 @@ static unsigned long shmem_default_max_inodes(void) #endif
static int shmem_swapin_folio(struct inode *inode, pgoff_t index, - struct folio **foliop, enum sgp_type sgp, - gfp_t gfp, struct vm_area_struct *vma, - vm_fault_t *fault_type); + struct folio **foliop, enum sgp_type sgp, gfp_t gfp, + struct mm_struct *fault_mm, vm_fault_t *fault_type);
static inline struct shmem_sb_info *SHMEM_SB(struct super_block *sb) { @@ -766,12 +765,10 @@ static unsigned long shmem_unused_huge_shrink(struct shmem_sb_info *sbinfo, */ static int shmem_add_to_page_cache(struct folio *folio, struct address_space *mapping, - pgoff_t index, void *expected, gfp_t gfp, - struct mm_struct *charge_mm) + pgoff_t index, void *expected, gfp_t gfp) { XA_STATE_ORDER(xas, &mapping->i_pages, index, folio_order(folio)); long nr = folio_nr_pages(folio); - int error;
VM_BUG_ON_FOLIO(index != round_down(index, nr), folio); VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio); @@ -782,16 +779,7 @@ static int shmem_add_to_page_cache(struct folio *folio, folio->mapping = mapping; folio->index = index;
- if (!folio_test_swapcache(folio)) { - error = mem_cgroup_charge(folio, charge_mm, gfp); - if (error) { - if (folio_test_pmd_mappable(folio)) { - count_vm_event(THP_FILE_FALLBACK); - count_vm_event(THP_FILE_FALLBACK_CHARGE); - } - goto error; - } - } + gfp &= GFP_RECLAIM_MASK; folio_throttle_swaprate(folio, gfp);
do { @@ -820,15 +808,12 @@ static int shmem_add_to_page_cache(struct folio *folio, } while (xas_nomem(&xas, gfp));
if (xas_error(&xas)) { - error = xas_error(&xas); - goto error; + folio->mapping = NULL; + folio_ref_sub(folio, nr); + return xas_error(&xas); }
return 0; -error: - folio->mapping = NULL; - folio_ref_sub(folio, nr); - return error; }
/* @@ -1349,10 +1334,8 @@ static int shmem_unuse_swap_entries(struct inode *inode,
if (!xa_is_value(folio)) continue; - error = shmem_swapin_folio(inode, indices[i], - &folio, SGP_CACHE, - mapping_gfp_mask(mapping), - NULL, NULL); + error = shmem_swapin_folio(inode, indices[i], &folio, SGP_CACHE, + mapping_gfp_mask(mapping), NULL, NULL); if (error == 0) { folio_unlock(folio); folio_put(folio); @@ -1841,12 +1824,11 @@ static void shmem_set_folio_swapin_error(struct inode *inode, pgoff_t index, */ static int shmem_swapin_folio(struct inode *inode, pgoff_t index, struct folio **foliop, enum sgp_type sgp, - gfp_t gfp, struct vm_area_struct *vma, + gfp_t gfp, struct mm_struct *fault_mm, vm_fault_t *fault_type) { struct address_space *mapping = inode->i_mapping; struct shmem_inode_info *info = SHMEM_I(inode); - struct mm_struct *charge_mm = vma ? vma->vm_mm : NULL; struct swap_info_struct *si; struct folio *folio = NULL; swp_entry_t swap; @@ -1874,7 +1856,7 @@ static int shmem_swapin_folio(struct inode *inode, pgoff_t index, if (fault_type) { *fault_type |= VM_FAULT_MAJOR; count_vm_event(PGMAJFAULT); - count_memcg_event_mm(charge_mm, PGMAJFAULT); + count_memcg_event_mm(fault_mm, PGMAJFAULT); } /* Here we actually start the io */ folio = shmem_swapin(swap, gfp, info, index); @@ -1911,8 +1893,7 @@ static int shmem_swapin_folio(struct inode *inode, pgoff_t index, }
error = shmem_add_to_page_cache(folio, mapping, index, - swp_to_radix_entry(swap), gfp, - charge_mm); + swp_to_radix_entry(swap), gfp); if (error) goto failed;
@@ -1960,7 +1941,7 @@ static int shmem_get_folio_gfp(struct inode *inode, pgoff_t index, struct address_space *mapping = inode->i_mapping; struct shmem_inode_info *info = SHMEM_I(inode); struct shmem_sb_info *sbinfo; - struct mm_struct *charge_mm; + struct mm_struct *fault_mm; struct folio *folio; pgoff_t hindex; gfp_t huge_gfp; @@ -1977,7 +1958,7 @@ static int shmem_get_folio_gfp(struct inode *inode, pgoff_t index, }
sbinfo = SHMEM_SB(inode->i_sb); - charge_mm = vma ? vma->vm_mm : NULL; + fault_mm = vma ? vma->vm_mm : NULL;
folio = filemap_get_entry(mapping, index); if (folio && vma && userfaultfd_minor(vma)) { @@ -1989,7 +1970,7 @@ static int shmem_get_folio_gfp(struct inode *inode, pgoff_t index,
if (xa_is_value(folio)) { error = shmem_swapin_folio(inode, index, &folio, - sgp, gfp, vma, fault_type); + sgp, gfp, fault_mm, fault_type); if (error == -EEXIST) goto repeat;
@@ -2077,9 +2058,16 @@ static int shmem_get_folio_gfp(struct inode *inode, pgoff_t index, if (sgp == SGP_WRITE) __folio_set_referenced(folio);
- error = shmem_add_to_page_cache(folio, mapping, hindex, - NULL, gfp & GFP_RECLAIM_MASK, - charge_mm); + error = mem_cgroup_charge(folio, fault_mm, gfp); + if (error) { + if (folio_test_pmd_mappable(folio)) { + count_vm_event(THP_FILE_FALLBACK); + count_vm_event(THP_FILE_FALLBACK_CHARGE); + } + goto unacct; + } + + error = shmem_add_to_page_cache(folio, mapping, hindex, NULL, gfp); if (error) goto unacct;
@@ -2677,8 +2665,10 @@ int shmem_mfill_atomic_pte(pmd_t *dst_pmd, if (unlikely(pgoff >= max_off)) goto out_release;
- ret = shmem_add_to_page_cache(folio, mapping, pgoff, NULL, - gfp & GFP_RECLAIM_MASK, dst_vma->vm_mm); + ret = mem_cgroup_charge(folio, dst_vma->vm_mm, gfp); + if (ret) + goto out_release; + ret = shmem_add_to_page_cache(folio, mapping, pgoff, NULL, gfp); if (ret) goto out_release;