From 4dc7d37370951fe86216f03a4e0a6909f9b90a8c Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Tue, 26 Mar 2024 17:10:31 +0000 Subject: [PATCH] remove references to page->flags in documentation Mostly rewording, but remove entirely the copy of page_fixed_fake_head() in the documentation; we can refer people to the actual source if necessary. Link: https://lkml.kernel.org/r/20240326171045.410737-10-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Andrew Morton --- .../admin-guide/cgroup-v1/memory.rst | 4 ++-- Documentation/mm/vmemmap_dedup.rst | 22 +------------------ .../translations/zh_CN/core-api/cachetlb.rst | 2 +- mm/migrate.c | 2 +- mm/rmap.c | 4 ++-- 5 files changed, 7 insertions(+), 27 deletions(-) diff --git a/Documentation/admin-guide/cgroup-v1/memory.rst b/Documentation/admin-guide/cgroup-v1/memory.rst index ca7d9402f6be..46110e6a31bb 100644 --- a/Documentation/admin-guide/cgroup-v1/memory.rst +++ b/Documentation/admin-guide/cgroup-v1/memory.rst @@ -300,14 +300,14 @@ When oom event notifier is registered, event will be delivered. Lock order is as follows:: - Page lock (PG_locked bit of page->flags) + folio_lock mm->page_table_lock or split pte_lock folio_memcg_lock (memcg->move_lock) mapping->i_pages lock lruvec->lru_lock. Per-node-per-memcgroup LRU (cgroup's private LRU) is guarded by -lruvec->lru_lock; PG_lru bit of page->flags is cleared before +lruvec->lru_lock; the folio LRU flag is cleared before isolating a page from its LRU under lruvec->lru_lock. .. _cgroup-v1-memory-kernel-extension: diff --git a/Documentation/mm/vmemmap_dedup.rst b/Documentation/mm/vmemmap_dedup.rst index 593ede6d314b..b4a55b6569fa 100644 --- a/Documentation/mm/vmemmap_dedup.rst +++ b/Documentation/mm/vmemmap_dedup.rst @@ -180,27 +180,7 @@ this correctly. There is only **one** head ``struct page``, the tail ``struct page`` with ``PG_head`` are fake head ``struct page``. We need an approach to distinguish between those two different types of ``struct page`` so that ``compound_head()`` can return the real head ``struct page`` when the -parameter is the tail ``struct page`` but with ``PG_head``. The following code -snippet describes how to distinguish between real and fake head ``struct page``. - -.. code-block:: c - - if (test_bit(PG_head, &page->flags)) { - unsigned long head = READ_ONCE(page[1].compound_head); - - if (head & 1) { - if (head == (unsigned long)page + 1) - /* head struct page */ - else - /* tail struct page */ - } else { - /* head struct page */ - } - } - -We can safely access the field of the **page[1]** with ``PG_head`` because the -page is a compound page composed with at least two contiguous pages. -The implementation refers to ``page_fixed_fake_head()``. +parameter is the tail ``struct page`` but with ``PG_head``. Device DAX ========== diff --git a/Documentation/translations/zh_CN/core-api/cachetlb.rst b/Documentation/translations/zh_CN/core-api/cachetlb.rst index b4a76ec75daa..64295c61d1c1 100644 --- a/Documentation/translations/zh_CN/core-api/cachetlb.rst +++ b/Documentation/translations/zh_CN/core-api/cachetlb.rst @@ -260,7 +260,7 @@ HyperSparc cpu就是这样一个具有这种属性的cpu。 如果D-cache别名不是一个问题，这个程序可以简单地定义为该架构上 的nop。 - 在page->flags (PG_arch_1)中有一个位是“架构私有”。内核保证， + 在folio->flags (PG_arch_1)中有一个位是“架构私有”。内核保证， 对于分页缓存的页面，当这样的页面第一次进入分页缓存时，它将清除 这个位。 diff --git a/mm/migrate.c b/mm/migrate.c index a31aa75d223d..285072bca29c 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -113,7 +113,7 @@ bool isolate_movable_page(struct page *page, isolate_mode_t mode) if (!mops->isolate_page(&folio->page, mode)) goto out_no_isolated; - /* Driver shouldn't use PG_isolated bit of page->flags */ + /* Driver shouldn't use the isolated flag */ WARN_ON_ONCE(folio_test_isolated(folio)); folio_set_isolated(folio); folio_unlock(folio); diff --git a/mm/rmap.c b/mm/rmap.c index d52759aa3ff7..5ee9e338d09b 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -23,7 +23,7 @@ * inode->i_rwsem (while writing or truncating, not reading or faulting) * mm->mmap_lock * mapping->invalidate_lock (in filemap_fault) - * page->flags PG_locked (lock_page) + * folio_lock * hugetlbfs_i_mmap_rwsem_key (in huge_pmd_share, see hugetlbfs below) * vma_start_write * mapping->i_mmap_rwsem @@ -50,7 +50,7 @@ * hugetlb_fault_mutex (hugetlbfs specific page fault mutex) * vma_lock (hugetlb specific lock for pmd_sharing) * mapping->i_mmap_rwsem (also used for hugetlb pmd sharing) - * page->flags PG_locked (lock_page) + * folio_lock */ #include