From: Andres Lagar-Cavilla Date: Fri, 20 May 2016 00:12:47 +0000 (-0700) Subject: tmpfs: mem_cgroup charge fault to vm_mm not current mm X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=9e18eb29356b7dfd55183bd42cf73919d1590835;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git tmpfs: mem_cgroup charge fault to vm_mm not current mm Although shmem_fault() has been careful to count a major fault to vm_mm, shmem_getpage_gfp() has been careless in charging a remote access fault to current->mm owner's memcg instead of to vma->vm_mm owner's memcg: that is inconsistent with all the mem_cgroup charging on remote access faults in mm/memory.c. Fix it by passing fault_mm along with fault_type to shmem_get_page_gfp(); but in that case, now knowing the right mm, it's better for it to handle the PGMAJFAULT updates itself. And let's keep this clutter out of most callers' way: change the common shmem_getpage() wrapper to hide fault_mm and fault_type as well as gfp. Signed-off-by: Andres Lagar-Cavilla Signed-off-by: Hugh Dickins Cc: "Kirill A. Shutemov" Cc: Andrea Arcangeli Cc: Andres Lagar-Cavilla Cc: Yang Shi Cc: Ning Qu Cc: Mel Gorman Cc: Konstantin Khlebnikov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/mm/shmem.c b/mm/shmem.c index 6d2de2c1bf11..e418a995427d 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -121,13 +121,14 @@ static bool shmem_should_replace_page(struct page *page, gfp_t gfp); static int shmem_replace_page(struct page **pagep, gfp_t gfp, struct shmem_inode_info *info, pgoff_t index); static int shmem_getpage_gfp(struct inode *inode, pgoff_t index, - struct page **pagep, enum sgp_type sgp, gfp_t gfp, int *fault_type); + struct page **pagep, enum sgp_type sgp, + gfp_t gfp, struct mm_struct *fault_mm, int *fault_type); static inline int shmem_getpage(struct inode *inode, pgoff_t index, - struct page **pagep, enum sgp_type sgp, int *fault_type) + struct page **pagep, enum sgp_type sgp) { return shmem_getpage_gfp(inode, index, pagep, sgp, - mapping_gfp_mask(inode->i_mapping), fault_type); + mapping_gfp_mask(inode->i_mapping), NULL, NULL); } static inline struct shmem_sb_info *SHMEM_SB(struct super_block *sb) @@ -527,7 +528,7 @@ static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend, if (partial_start) { struct page *page = NULL; - shmem_getpage(inode, start - 1, &page, SGP_READ, NULL); + shmem_getpage(inode, start - 1, &page, SGP_READ); if (page) { unsigned int top = PAGE_SIZE; if (start > end) { @@ -542,7 +543,7 @@ static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend, } if (partial_end) { struct page *page = NULL; - shmem_getpage(inode, end, &page, SGP_READ, NULL); + shmem_getpage(inode, end, &page, SGP_READ); if (page) { zero_user_segment(page, 0, partial_end); set_page_dirty(page); @@ -1115,14 +1116,19 @@ static int shmem_replace_page(struct page **pagep, gfp_t gfp, * * If we allocate a new one we do not mark it dirty. That's up to the * vm. If we swap it in we mark it dirty since we also free the swap - * entry since a page cannot live in both the swap and page cache + * entry since a page cannot live in both the swap and page cache. + * + * fault_mm and fault_type are only supplied by shmem_fault: + * otherwise they are NULL. */ static int shmem_getpage_gfp(struct inode *inode, pgoff_t index, - struct page **pagep, enum sgp_type sgp, gfp_t gfp, int *fault_type) + struct page **pagep, enum sgp_type sgp, gfp_t gfp, + struct mm_struct *fault_mm, int *fault_type) { struct address_space *mapping = inode->i_mapping; struct shmem_inode_info *info; struct shmem_sb_info *sbinfo; + struct mm_struct *charge_mm; struct mem_cgroup *memcg; struct page *page; swp_entry_t swap; @@ -1168,14 +1174,19 @@ repeat: */ info = SHMEM_I(inode); sbinfo = SHMEM_SB(inode->i_sb); + charge_mm = fault_mm ? : current->mm; if (swap.val) { /* Look it up and read it in.. */ page = lookup_swap_cache(swap); if (!page) { - /* here we actually do the io */ - if (fault_type) + /* Or update major stats only when swapin succeeds?? */ + if (fault_type) { *fault_type |= VM_FAULT_MAJOR; + count_vm_event(PGMAJFAULT); + mem_cgroup_count_vm_event(fault_mm, PGMAJFAULT); + } + /* Here we actually start the io */ page = shmem_swapin(swap, gfp, info, index); if (!page) { error = -ENOMEM; @@ -1202,7 +1213,7 @@ repeat: goto failed; } - error = mem_cgroup_try_charge(page, current->mm, gfp, &memcg, + error = mem_cgroup_try_charge(page, charge_mm, gfp, &memcg, false); if (!error) { error = shmem_add_to_page_cache(page, mapping, index, @@ -1263,7 +1274,7 @@ repeat: if (sgp == SGP_WRITE) __SetPageReferenced(page); - error = mem_cgroup_try_charge(page, current->mm, gfp, &memcg, + error = mem_cgroup_try_charge(page, charge_mm, gfp, &memcg, false); if (error) goto decused; @@ -1352,6 +1363,7 @@ unlock: static int shmem_fault(struct vm_area_struct *vma, struct vm_fault *vmf) { struct inode *inode = file_inode(vma->vm_file); + gfp_t gfp = mapping_gfp_mask(inode->i_mapping); int error; int ret = VM_FAULT_LOCKED; @@ -1413,14 +1425,10 @@ static int shmem_fault(struct vm_area_struct *vma, struct vm_fault *vmf) spin_unlock(&inode->i_lock); } - error = shmem_getpage(inode, vmf->pgoff, &vmf->page, SGP_CACHE, &ret); + error = shmem_getpage_gfp(inode, vmf->pgoff, &vmf->page, SGP_CACHE, + gfp, vma->vm_mm, &ret); if (error) return ((error == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS); - - if (ret & VM_FAULT_MAJOR) { - count_vm_event(PGMAJFAULT); - mem_cgroup_count_vm_event(vma->vm_mm, PGMAJFAULT); - } return ret; } @@ -1567,7 +1575,7 @@ shmem_write_begin(struct file *file, struct address_space *mapping, return -EPERM; } - return shmem_getpage(inode, index, pagep, SGP_WRITE, NULL); + return shmem_getpage(inode, index, pagep, SGP_WRITE); } static int @@ -1633,7 +1641,7 @@ static ssize_t shmem_file_read_iter(struct kiocb *iocb, struct iov_iter *to) break; } - error = shmem_getpage(inode, index, &page, sgp, NULL); + error = shmem_getpage(inode, index, &page, sgp); if (error) { if (error == -EINVAL) error = 0; @@ -1749,7 +1757,7 @@ static ssize_t shmem_file_splice_read(struct file *in, loff_t *ppos, error = 0; while (spd.nr_pages < nr_pages) { - error = shmem_getpage(inode, index, &page, SGP_CACHE, NULL); + error = shmem_getpage(inode, index, &page, SGP_CACHE); if (error) break; unlock_page(page); @@ -1771,8 +1779,7 @@ static ssize_t shmem_file_splice_read(struct file *in, loff_t *ppos, page = spd.pages[page_nr]; if (!PageUptodate(page) || page->mapping != mapping) { - error = shmem_getpage(inode, index, &page, - SGP_CACHE, NULL); + error = shmem_getpage(inode, index, &page, SGP_CACHE); if (error) break; unlock_page(page); @@ -2215,8 +2222,7 @@ static long shmem_fallocate(struct file *file, int mode, loff_t offset, else if (shmem_falloc.nr_unswapped > shmem_falloc.nr_falloced) error = -ENOMEM; else - error = shmem_getpage(inode, index, &page, SGP_FALLOC, - NULL); + error = shmem_getpage(inode, index, &page, SGP_FALLOC); if (error) { /* Remove the !PageUptodate pages we added */ shmem_undo_range(inode, @@ -2534,7 +2540,7 @@ static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *s inode->i_op = &shmem_short_symlink_operations; } else { inode_nohighmem(inode); - error = shmem_getpage(inode, 0, &page, SGP_WRITE, NULL); + error = shmem_getpage(inode, 0, &page, SGP_WRITE); if (error) { iput(inode); return error; @@ -2575,7 +2581,7 @@ static const char *shmem_get_link(struct dentry *dentry, return ERR_PTR(-ECHILD); } } else { - error = shmem_getpage(inode, 0, &page, SGP_READ, NULL); + error = shmem_getpage(inode, 0, &page, SGP_READ); if (error) return ERR_PTR(error); unlock_page(page); @@ -3479,7 +3485,8 @@ struct page *shmem_read_mapping_page_gfp(struct address_space *mapping, int error; BUG_ON(mapping->a_ops != &shmem_aops); - error = shmem_getpage_gfp(inode, index, &page, SGP_CACHE, gfp, NULL); + error = shmem_getpage_gfp(inode, index, &page, SGP_CACHE, + gfp, NULL, NULL); if (error) page = ERR_PTR(error); else