Re: memleaks, acpi + ext4 + tty

["Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>]

On Fri, Aug 28, 2009 at 05:32:10PM +0100, Catalin Marinas wrote:
> "Luis R. Rodriguez" <mcgrof@gmail.com> wrote:
> > I have an assorted collection of kmemleak reports for acpi, ext4 and
> > tty, not sure how to read these yet to fix so figure I'd at least post
> > them. To reproduce I can just dd=/dev/zero to some big file and played
> > some video.
> 
> If you do a few echo scan > /sys/kernel/debug/kmemleak, do they
> disappear (i.e. transient false positives)?
> 
> Which kernel version is this?
> 
> > unreferenced object 0xffff88003e0015c0 (size 64):
> >   comm "swapper", pid 1, jiffies 4294892352
> >   backtrace:
> >     [<ffffffff81121fad>] create_object+0x13d/0x2d0
> >     [<ffffffff81122265>] kmemleak_alloc+0x25/0x60
> >     [<ffffffff81118a03>] kmem_cache_alloc_node+0x193/0x200
> >     [<ffffffff8152509e>] process_zones+0x70/0x1cd
> >     [<ffffffff81525230>] pageset_cpuup_callback+0x35/0x92
> >     [<ffffffff8152c9b7>] notifier_call_chain+0x47/0x90
> >     [<ffffffff81078549>] __raw_notifier_call_chain+0x9/0x10
> >     [<ffffffff81523f25>] _cpu_up+0x75/0x130
> >     [<ffffffff8152403a>] cpu_up+0x5a/0x6a
> >     [<ffffffff8181969e>] kernel_init+0xcc/0x1ba
> >     [<ffffffff810130ca>] child_rip+0xa/0x20
> >     [<ffffffffffffffff>] 0xffffffffffffffff
> 
> Can't really tell. Maybe a false positive caused by kmemleak not
> scanning the pgdata node_zones. Can you post your .config file?
> 
> > unreferenced object 0xffff88003cb5f700 (size 64):
> >   comm "swapper", pid 1, jiffies 4294892459
> >   backtrace:
> >     [<ffffffff81121fad>] create_object+0x13d/0x2d0
> >     [<ffffffff81122265>] kmemleak_alloc+0x25/0x60
> >     [<ffffffff81119f3b>] __kmalloc+0x16b/0x250
> >     [<ffffffff812bb549>] kzalloc+0xf/0x11
> >     [<ffffffff812bbb53>] acpi_add_single_object+0x58e/0xd3c
> >     [<ffffffff812bc51c>] acpi_bus_scan+0x125/0x1af
> >     [<ffffffff81842361>] acpi_scan_init+0xc8/0xe9
> >     [<ffffffff8184211c>] acpi_init+0x21f/0x265
> >     [<ffffffff8100a05b>] do_one_initcall+0x4b/0x1b0
> >     [<ffffffff81819736>] kernel_init+0x164/0x1ba
> >     [<ffffffff810130ca>] child_rip+0xa/0x20
> >     [<ffffffffffffffff>] 0xffffffffffffffff
> 
> I get ACPI reports as well and they may be real leaks. However, I
> didn't have time to analyse the code (pretty complicated reference
> counting).
> 
> > unreferenced object 0xffff880039571800 (size 1024):
> >   comm "exe", pid 1168, jiffies 4294893410
> >   backtrace:
> >     [<ffffffff81121fad>] create_object+0x13d/0x2d0
> >     [<ffffffff81122265>] kmemleak_alloc+0x25/0x60
> >     [<ffffffff81119f3b>] __kmalloc+0x16b/0x250
> >     [<ffffffff811e1d71>] ext4_mb_init+0x1a1/0x590
> >     [<ffffffff811d2da3>] ext4_fill_super+0x1df3/0x26c0
> >     [<ffffffff8112774f>] get_sb_bdev+0x16f/0x1b0
> >     [<ffffffff811c8fd3>] ext4_get_sb+0x13/0x20
> >     [<ffffffff81127216>] vfs_kern_mount+0x76/0x180
> >     [<ffffffff8112738d>] do_kern_mount+0x4d/0x130
> >     [<ffffffff8113fc57>] do_mount+0x307/0x8b0
> >     [<ffffffff8114028f>] sys_mount+0x8f/0xe0
> >     [<ffffffff81011f02>] system_call_fastpath+0x16/0x1b
> >     [<ffffffffffffffff>] 0xffffffffffffffff
> 
> The ext4 reports are real leaks and patch was posted here -
> http://lkml.org/lkml/2009/7/15/62. However, it hasn't been merged into
> mainline yet (I cc'ed Aneesh).
> 

The patch is part of ext4-patchqueue  http://repo.or.cz/w/ext4-patch-queue.git

Ted,

Any plans to push the patches to linus tree soon ?

-aneesh