| Message ID | 3635a17b9a0cf4be011a886415bf620b1c682ff6.1676382188.git.baolin.wang@linux.alibaba.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Change the return value for page isolation functions | expand |
On Tue, 14 Feb 2023 21:59:30 +0800 Baolin Wang <baolin.wang@linux.alibaba.com> wrote: > The isolate_lru_page() can only return 0 or -EBUSY, and most users did > not care about the negative error of isolate_lru_page(), except one user > in add_page_for_migration(). So we can convert the isolate_lru_page() to > return a boolean value, which can help to make the code more clear when > checking the return value of isolate_lru_page(). > > Also convert all users' logic of checking the isolation state. > > No functional changes intended. > > Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> > --- > mm/folio-compat.c | 12 +++--------- > mm/internal.h | 2 +- > mm/khugepaged.c | 2 +- > mm/memcontrol.c | 4 ++-- > mm/memory-failure.c | 4 ++-- > mm/memory_hotplug.c | 2 +- > mm/migrate.c | 9 ++++++--- > mm/migrate_device.c | 2 +- > 8 files changed, 17 insertions(+), 20 deletions(-) > [...] > diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c > index a1e8c3e9ab08..17ed80707518 100644 > --- a/mm/memory_hotplug.c > +++ b/mm/memory_hotplug.c > @@ -1668,7 +1668,7 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) > * LRU and non-lru movable pages. > */ > if (PageLRU(page)) > - ret = isolate_lru_page(page); > + ret = !isolate_lru_page(page); This may change return value of this function. That is, this function will return 1 instead of -EBUSY after this change. It's not a real issue as no caller of this function takes care of the return value, though. Thanks, SJ > else > ret = isolate_movable_page(page, ISOLATE_UNEVICTABLE); > if (!ret) { /* Success */ [...]
On 2/15/2023 3:32 AM, SeongJae Park wrote: > On Tue, 14 Feb 2023 21:59:30 +0800 Baolin Wang <baolin.wang@linux.alibaba.com> wrote: > >> The isolate_lru_page() can only return 0 or -EBUSY, and most users did >> not care about the negative error of isolate_lru_page(), except one user >> in add_page_for_migration(). So we can convert the isolate_lru_page() to >> return a boolean value, which can help to make the code more clear when >> checking the return value of isolate_lru_page(). >> >> Also convert all users' logic of checking the isolation state. >> >> No functional changes intended. >> >> Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> >> --- >> mm/folio-compat.c | 12 +++--------- >> mm/internal.h | 2 +- >> mm/khugepaged.c | 2 +- >> mm/memcontrol.c | 4 ++-- >> mm/memory-failure.c | 4 ++-- >> mm/memory_hotplug.c | 2 +- >> mm/migrate.c | 9 ++++++--- >> mm/migrate_device.c | 2 +- >> 8 files changed, 17 insertions(+), 20 deletions(-) >> > [...] >> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c >> index a1e8c3e9ab08..17ed80707518 100644 >> --- a/mm/memory_hotplug.c >> +++ b/mm/memory_hotplug.c >> @@ -1668,7 +1668,7 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) >> * LRU and non-lru movable pages. >> */ >> if (PageLRU(page)) >> - ret = isolate_lru_page(page); >> + ret = !isolate_lru_page(page); > > This may change return value of this function. That is, this function will > return 1 instead of -EBUSY after this change. It's not a real issue as no > caller of this function takes care of the return value, though. Yes, I've also thought about this. OK, I can keep the original logic here by adding a new variable. Thanks. isolated = isolate_lru_page(page); ret = isolated ? 0 : -EBUSY;
diff --git a/mm/folio-compat.c b/mm/folio-compat.c index 540373cf904e..cabcd1de9ecb 100644 --- a/mm/folio-compat.c +++ b/mm/folio-compat.c @@ -113,17 +113,11 @@ struct page *grab_cache_page_write_begin(struct address_space *mapping, } EXPORT_SYMBOL(grab_cache_page_write_begin); -int isolate_lru_page(struct page *page) +bool isolate_lru_page(struct page *page) { - bool ret; - if (WARN_RATELIMIT(PageTail(page), "trying to isolate tail page")) - return -EBUSY; - ret = folio_isolate_lru((struct folio *)page); - if (ret) - return 0; - - return -EBUSY; + return false; + return folio_isolate_lru((struct folio *)page); } void putback_lru_page(struct page *page) diff --git a/mm/internal.h b/mm/internal.h index 8645e8496537..fc01fd092ea5 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -187,7 +187,7 @@ pgprot_t __init early_memremap_pgprot_adjust(resource_size_t phys_addr, /* * in mm/vmscan.c: */ -int isolate_lru_page(struct page *page); +bool isolate_lru_page(struct page *page); bool folio_isolate_lru(struct folio *folio); void putback_lru_page(struct page *page); void folio_putback_lru(struct folio *folio); diff --git a/mm/khugepaged.c b/mm/khugepaged.c index cee659cfa3c1..8dbc39896811 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -659,7 +659,7 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma, * Isolate the page to avoid collapsing an hugepage * currently in use by the VM. */ - if (isolate_lru_page(page)) { + if (!isolate_lru_page(page)) { unlock_page(page); result = SCAN_DEL_PAGE_LRU; goto out; diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 17335459d8dc..e8fd42be5fab 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -6176,7 +6176,7 @@ static int mem_cgroup_move_charge_pte_range(pmd_t *pmd, target_type = get_mctgt_type_thp(vma, addr, *pmd, &target); if (target_type == MC_TARGET_PAGE) { page = target.page; - if (!isolate_lru_page(page)) { + if (isolate_lru_page(page)) { if (!mem_cgroup_move_account(page, true, mc.from, mc.to)) { mc.precharge -= HPAGE_PMD_NR; @@ -6226,7 +6226,7 @@ static int mem_cgroup_move_charge_pte_range(pmd_t *pmd, */ if (PageTransCompound(page)) goto put; - if (!device && isolate_lru_page(page)) + if (!device && !isolate_lru_page(page)) goto put; if (!mem_cgroup_move_account(page, false, mc.from, mc.to)) { diff --git a/mm/memory-failure.c b/mm/memory-failure.c index db85c2d37f70..e504362fdb23 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -846,7 +846,7 @@ static const char * const action_page_types[] = { */ static int delete_from_lru_cache(struct page *p) { - if (!isolate_lru_page(p)) { + if (isolate_lru_page(p)) { /* * Clear sensible page flags, so that the buddy system won't * complain when the page is unpoison-and-freed. @@ -2513,7 +2513,7 @@ static bool isolate_page(struct page *page, struct list_head *pagelist) bool lru = !__PageMovable(page); if (lru) - isolated = !isolate_lru_page(page); + isolated = isolate_lru_page(page); else isolated = !isolate_movable_page(page, ISOLATE_UNEVICTABLE); diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index a1e8c3e9ab08..17ed80707518 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1668,7 +1668,7 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) * LRU and non-lru movable pages. */ if (PageLRU(page)) - ret = isolate_lru_page(page); + ret = !isolate_lru_page(page); else ret = isolate_movable_page(page, ISOLATE_UNEVICTABLE); if (!ret) { /* Success */ diff --git a/mm/migrate.c b/mm/migrate.c index ef68a1aff35c..53010a142e7f 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -2132,11 +2132,14 @@ static int add_page_for_migration(struct mm_struct *mm, unsigned long addr, } } else { struct page *head; + bool isolated; head = compound_head(page); - err = isolate_lru_page(head); - if (err) + isolated = isolate_lru_page(head); + if (!isolated) { + err = -EBUSY; goto out_putpage; + } err = 1; list_add_tail(&head->lru, pagelist); @@ -2541,7 +2544,7 @@ static int numamigrate_isolate_page(pg_data_t *pgdat, struct page *page) return 0; } - if (isolate_lru_page(page)) + if (!isolate_lru_page(page)) return 0; mod_node_page_state(page_pgdat(page), NR_ISOLATED_ANON + page_is_file_lru(page), diff --git a/mm/migrate_device.c b/mm/migrate_device.c index 6c3740318a98..d30c9de60b0d 100644 --- a/mm/migrate_device.c +++ b/mm/migrate_device.c @@ -388,7 +388,7 @@ static unsigned long migrate_device_unmap(unsigned long *src_pfns, allow_drain = false; } - if (isolate_lru_page(page)) { + if (!isolate_lru_page(page)) { src_pfns[i] &= ~MIGRATE_PFN_MIGRATE; restore++; continue;
The isolate_lru_page() can only return 0 or -EBUSY, and most users did not care about the negative error of isolate_lru_page(), except one user in add_page_for_migration(). So we can convert the isolate_lru_page() to return a boolean value, which can help to make the code more clear when checking the return value of isolate_lru_page(). Also convert all users' logic of checking the isolation state. No functional changes intended. Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> --- mm/folio-compat.c | 12 +++--------- mm/internal.h | 2 +- mm/khugepaged.c | 2 +- mm/memcontrol.c | 4 ++-- mm/memory-failure.c | 4 ++-- mm/memory_hotplug.c | 2 +- mm/migrate.c | 9 ++++++--- mm/migrate_device.c | 2 +- 8 files changed, 17 insertions(+), 20 deletions(-)