On Wed, May 07, 2014 at 03:58:08AM +0100, Jaegeuk Kim wrote: > And then when I tested again with Catalin's patch, it still throws the > following warning. > Is it false alarm? BTW, you can try this kmemleak branch: git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/linux-aarch64.git kmemleak > unreferenced object 0xffff880004226da0 (size 576): > comm "fsstress", pid 14590, jiffies 4295191259 (age 706.308s) > hex dump (first 32 bytes): > 01 00 00 00 81 ff ff ff 00 00 00 00 00 00 00 00 ................ > 50 89 34 81 ff ff ff ff b8 6d 22 04 00 88 ff ff P.4......m"..... > backtrace: > [<ffffffff816c02e8>] kmemleak_update_trace+0x58/0x80 > [<ffffffff81349517>] radix_tree_node_alloc+0x77/0xa0 > [<ffffffff81349718>] __radix_tree_create+0x1d8/0x230 > [<ffffffff8113286c>] __add_to_page_cache_locked+0x9c/0x1b0 > [<ffffffff811329a8>] add_to_page_cache_lru+0x28/0x80 > [<ffffffff81132f58>] grab_cache_page_write_begin+0x98/0xf0 > [<ffffffffa02e4bf4>] f2fs_write_begin+0xb4/0x3c0 [f2fs] > [<ffffffff81131b77>] generic_perform_write+0xc7/0x1c0 > [<ffffffff81133b7d>] __generic_file_aio_write+0x1cd/0x3f0 > [<ffffffff81133dfe>] generic_file_aio_write+0x5e/0xe0 > [<ffffffff81195c5a>] do_sync_write+0x5a/0x90 > [<ffffffff811968d2>] vfs_write+0xc2/0x1d0 > [<ffffffff81196daf>] SyS_write+0x4f/0xb0 > [<ffffffff816dead2>] system_call_fastpath+0x16/0x1b > [<ffffffffffffffff>] 0xffffffffffffffff OK, it shows that the allocation happens via add_to_page_cache_locked() and I guess it's page_cache_tree_insert() which calls __radix_tree_create() (the latter reusing the preloaded node). I'm not familiar enough to this code (radix-tree.c and filemap.c) to tell where the node should have been freed, who keeps track of it. At a quick look at the hex dump (assuming that the above leak is struct radix_tree_node): .path = 1 .count = -0x7f (or 0xffffff81 as unsigned int) union { { .parent = NULL .private_data = 0xffffffff81348950 } { .rcu_head.next = NULL .rcu_head.func = 0xffffffff81348950 } } The count is a bit suspicious. >From the union, it looks most likely like rcu_head information. Is radix_tree_node_rcu_free() function at the above rcu_head.func? Could you please send us your .config file? Also, if you run echo scan > /sys/kernel/debug/kmemleak a few times, do any of the above leaks disappear (in case the above are some transient rcu freeing reports; normally this shouldn't happen as the objects are still referred but I'll look at the relevant code once I have your .config). Thanks. -- Catalin -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>