search for: vm_bug_on_pag

Hello Minchan, On (03/30/16 16:12), Minchan Kim wrote: [..] > @@ -1835,23 +1827,31 @@ static void __zs_compact(struct zs_pool *pool, struct size_class *class) > if (!migrate_zspage(pool, class, &cc)) > break; > > - putback_zspage(pool, class, dst_page); > + VM_BUG_ON_PAGE(putback_zspage(pool, class, > + dst_page) == ZS_EMPTY, dst_page); can this VM_BUG_ON_PAGE() condition ever be true? > } > /* Stop if we couldn't find slot */ > if (dst_page == NULL) > break; > - putback_zspage(pool, class, dst_page); > - if (putback_zsp...

Hello Minchan, On (03/30/16 16:12), Minchan Kim wrote: [..] > @@ -1835,23 +1827,31 @@ static void __zs_compact(struct zs_pool *pool, struct size_class *class) > if (!migrate_zspage(pool, class, &cc)) > break; > > - putback_zspage(pool, class, dst_page); > + VM_BUG_ON_PAGE(putback_zspage(pool, class, > + dst_page) == ZS_EMPTY, dst_page); can this VM_BUG_ON_PAGE() condition ever be true? > } > /* Stop if we couldn't find slot */ > if (dst_page == NULL) > break; > - putback_zspage(pool, class, dst_page); > - if (putback_zsp...

Hello, On (03/30/16 16:12), Minchan Kim wrote: [..] > +static int get_zspage_inuse(struct page *first_page) > +{ > + struct zs_meta *m; > + > + VM_BUG_ON_PAGE(!is_first_page(first_page), first_page); > + > + m = (struct zs_meta *)&first_page->mapping; .. > +static void set_zspage_inuse(struct page *first_page, int val) > +{ > + struct zs_meta *m; > + > + VM_BUG_ON_PAGE(!is_first_page(first_page), first_page); > + > + m...

Hello, On (03/30/16 16:12), Minchan Kim wrote: [..] > +static int get_zspage_inuse(struct page *first_page) > +{ > + struct zs_meta *m; > + > + VM_BUG_ON_PAGE(!is_first_page(first_page), first_page); > + > + m = (struct zs_meta *)&first_page->mapping; .. > +static void set_zspage_inuse(struct page *first_page, int val) > +{ > + struct zs_meta *m; > + > + VM_BUG_ON_PAGE(!is_first_page(first_page), first_page); > + > + m...

There are many BUG_ON in zsmalloc.c which is not recommened so change them as alternatives. Normal rule is as follows: 1. avoid BUG_ON if possible. Instead, use VM_BUG_ON or VM_BUG_ON_PAGE 2. use VM_BUG_ON_PAGE if we need to see struct page's fields 3. use those assertion in primitive functions so higher functions can rely on the assertion in the primitive function. 4. Don't use assertion if following instruction can trigger Oops Signed-off-by: Minchan Kim <minchan at ke...

...ion.c > >+++ b/mm/compaction.c > >@@ -81,6 +81,39 @@ static inline bool migrate_async_suitable(int migratetype) > > > > #ifdef CONFIG_COMPACTION > > > >+int PageMovable(struct page *page) > >+{ > >+ struct address_space *mapping; > >+ > >+ VM_BUG_ON_PAGE(!PageLocked(page), page); > >+ if (!__PageMovable(page)) > >+ return 0; > >+ > >+ mapping = page_mapping(page); > >+ if (mapping && mapping->a_ops && mapping->a_ops->isolate_page) > >+ return 1; > >+ > >+ return 0; > &gt...

...ion.c > >+++ b/mm/compaction.c > >@@ -81,6 +81,39 @@ static inline bool migrate_async_suitable(int migratetype) > > > > #ifdef CONFIG_COMPACTION > > > >+int PageMovable(struct page *page) > >+{ > >+ struct address_space *mapping; > >+ > >+ VM_BUG_ON_PAGE(!PageLocked(page), page); > >+ if (!__PageMovable(page)) > >+ return 0; > >+ > >+ mapping = page_mapping(page); > >+ if (mapping && mapping->a_ops && mapping->a_ops->isolate_page) > >+ return 1; > >+ > >+ return 0; > &gt...

...* class maintains a list of zspages where each zspage is divided @@ -1052,6 +1065,44 @@ void lock_zspage(struct page *first_page) } while ((cursor = get_next_page(cursor)) != NULL); } +int trylock_zspage(struct page *first_page, struct page *locked_page) +{ + struct page *cursor, *fail; + + VM_BUG_ON_PAGE(!is_first_page(first_page), first_page); + + for (cursor = first_page; cursor != NULL; cursor = + get_next_page(cursor)) { + if (cursor != locked_page) { + if (!trylock_page(cursor)) { + fail = cursor; + goto unlock; + } + } + } + + return 1; +unlock: + for (cursor = first_page; curs...

Hi Minchan, [auto build test WARNING on next-20160318] [cannot apply to v4.5-rc7 v4.5-rc6 v4.5-rc5 v4.5] [if your patch is applied to the wrong git tree, please drop us a note to help improving the system] url: https://github.com/0day-ci/linux/commits/Minchan-Kim/Support-non-lru-page-migration/20160321-143339 coccinelle warnings: (new ones prefixed by >>) >>

Hi Minchan, [auto build test WARNING on next-20160318] [cannot apply to v4.5-rc7 v4.5-rc6 v4.5-rc5 v4.5] [if your patch is applied to the wrong git tree, please drop us a note to help improving the system] url: https://github.com/0day-ci/linux/commits/Minchan-Kim/Support-non-lru-page-migration/20160321-143339 coccinelle warnings: (new ones prefixed by >>) >>

...:12), Minchan Kim wrote: > [..] > > @@ -1835,23 +1827,31 @@ static void __zs_compact(struct zs_pool *pool, struct size_class *class) > > if (!migrate_zspage(pool, class, &cc)) > > break; > > > > - putback_zspage(pool, class, dst_page); > > + VM_BUG_ON_PAGE(putback_zspage(pool, class, > > + dst_page) == ZS_EMPTY, dst_page); > > can this VM_BUG_ON_PAGE() condition ever be true? I guess it is remained thing after I rebased to catch any mistake. But I'm heavily chainging this part. Please review next version instead of this after a...

...fullness:FULLNESS_BITS; + unsigned long inuse:INUSE_BITS; +}; struct mapping_area { #ifdef CONFIG_PGTABLE_MAPPING @@ -412,28 +415,61 @@ static int is_last_page(struct page *page) return PagePrivate2(page); } +static int get_zspage_inuse(struct page *first_page) +{ + struct zs_meta *m; + + VM_BUG_ON_PAGE(!is_first_page(first_page), first_page); + + m = (struct zs_meta *)&first_page->mapping; + + return m->inuse; +} + +static void set_zspage_inuse(struct page *first_page, int val) +{ + struct zs_meta *m; + + VM_BUG_ON_PAGE(!is_first_page(first_page), first_page); + + m = (struct zs_meta *...

...ist of zspages in a fullness group. - * page->mapping: override by struct zs_meta + * page->freelist: override by struct zs_meta * * Usage of struct page flags: * PG_private: identifies the first component page @@ -418,7 +418,7 @@ static int get_zspage_inuse(struct page *first_page) VM_BUG_ON_PAGE(!is_first_page(first_page), first_page); - m = (struct zs_meta *)&first_page->mapping; + m = (struct zs_meta *)&first_page->freelist; return m->inuse; } @@ -429,7 +429,7 @@ static void set_zspage_inuse(struct page *first_page, int val) VM_BUG_ON_PAGE(!is_first_page(firs...

...mpaction.c > +++ b/mm/compaction.c > @@ -81,6 +81,41 @@ static inline bool migrate_async_suitable(int migratetype) > > #ifdef CONFIG_COMPACTION > > +int PageMovable(struct page *page) > +{ > + struct address_space *mapping; > + > + WARN_ON(!PageLocked(page)); Why not VM_BUG_ON_PAGE as elsewhere? > + if (!__PageMovable(page)) > + goto out; Just return 0. > + > + mapping = page_mapping(page); > + if (mapping && mapping->a_ops && mapping->a_ops->isolate_page) > + return 1; > +out: > + return 0; > +} > +EXPORT_SYMBOL(Pa...

...mpaction.c > +++ b/mm/compaction.c > @@ -81,6 +81,41 @@ static inline bool migrate_async_suitable(int migratetype) > > #ifdef CONFIG_COMPACTION > > +int PageMovable(struct page *page) > +{ > + struct address_space *mapping; > + > + WARN_ON(!PageLocked(page)); Why not VM_BUG_ON_PAGE as elsewhere? > + if (!__PageMovable(page)) > + goto out; Just return 0. > + > + mapping = page_mapping(page); > + if (mapping && mapping->a_ops && mapping->a_ops->isolate_page) > + return 1; > +out: > + return 0; > +} > +EXPORT_SYMBOL(Pa...

Recently, I got many reports about perfermance degradation in embedded system(Android mobile phone, webOS TV and so on) and failed to fork easily. The problem was fragmentation caused by zram and GPU driver pages. Their pages cannot be migrated so compaction cannot work well, either so reclaimer ends up shrinking all of working set pages. It made system very slow and even to fail to fork easily.

Recently, I got many reports about perfermance degradation in embedded system(Android mobile phone, webOS TV and so on) and failed to fork easily. The problem was fragmentation caused by zram and GPU driver pages. Their pages cannot be migrated so compaction cannot work well, either so reclaimer ends up shrinking all of working set pages. It made system very slow and even to fail to fork easily.

Recently, I got many reports about perfermance degradation in embedded system(Android mobile phone, webOS TV and so on) and failed to fork easily. The problem was fragmentation caused by zram and GPU driver pages. Their pages cannot be migrated so compaction cannot work well, either so reclaimer ends up shrinking all of working set pages. It made system very slow and even to fail to fork easily.

Recently, I got many reports about perfermance degradation in embedded system(Android mobile phone, webOS TV and so on) and failed to fork easily. The problem was fragmentation caused by zram and GPU driver pages. Their pages cannot be migrated so compaction cannot work well, either so reclaimer ends up shrinking all of working set pages. It made system very slow and even to fail to fork easily.

Recently, I got many reports about perfermance degradation in embedded system(Android mobile phone, webOS TV and so on) and failed to fork easily. The problem was fragmentation caused by zram and GPU driver pages. Their pages cannot be migrated so compaction cannot work well, either so reclaimer ends up shrinking all of working set pages. It made system very slow and even to fail to fork easily.