On Sat, 2019-08-31 at 10:30 +0300, Leon Romanovsky wrote:
> Doug,
> 
> I think that it can be counted as good example why allowing memory
> leaks
> in drivers (HNS) is not so great idea.

Crashing the machine is worse.

> Thanks
> 
> On Fri, Aug 30, 2019 at 02:27:49PM -0400, Chuck Lever wrote:
> > > On Aug 30, 2019, at 2:03 PM, Chuck Lever <chuck.lever@oracle.com>
> > > wrote:
> > > 
> > > Hi Michal-
> > > 
> > > In the middle of some other testing, I got this kmemleak report
> > > while testing with FastLinq cards in iWARP mode:
> > > 
> > > unreferenced object 0xffff888458923340 (size 32):
> > >  comm "mount.nfs", pid 2294, jiffies 4298338848 (age 1144.337s)
> > >  hex dump (first 32 bytes):
> > >    20 1d 69 63 88 88 ff ff 20 1d 69 63 88 88 ff ff   .ic....
> > > .ic....
> > >    00 60 7a 69 84 88 ff ff 00 60 82 f9 00 00 00
> > > 00  .`zi.....`......
> > >  backtrace:
> > >    [<000000000df5bfed>] __kmalloc+0x128/0x176
> > >    [<0000000020724641>] qedr_alloc_pbl_tbl.constprop.44+0x3c/0x121
> > > [qedr]
> > >    [<00000000a361c591>] init_mr_info.constprop.41+0xaf/0x21f
> > > [qedr]
> > >    [<00000000e8049714>] qedr_alloc_mr+0x95/0x2c1 [qedr]
> > >    [<000000000e6102bc>] ib_alloc_mr_user+0x31/0x96 [ib_core]
> > >    [<00000000d254a9fb>] frwr_init_mr+0x23/0x121 [rpcrdma]
> > >    [<00000000a0364e35>] rpcrdma_mrs_create+0x45/0xea [rpcrdma]
> > >    [<00000000fd6bf282>] rpcrdma_buffer_create+0x9e/0x1c9 [rpcrdma]
> > >    [<00000000be3a1eba>] xprt_setup_rdma+0x109/0x279 [rpcrdma]
> > >    [<00000000b736b88f>] xprt_create_transport+0x39/0x19a [sunrpc]
> > >    [<000000001024e4dc>] rpc_create+0x118/0x1ab [sunrpc]
> > >    [<00000000cca43a49>] nfs_create_rpc_client+0xf8/0x15f [nfs]
> > >    [<00000000073c962c>] nfs_init_client+0x1a/0x3b [nfs]
> > >    [<00000000b03964c4>] nfs_init_server+0xc1/0x212 [nfs]
> > >    [<000000001c71f609>] nfs_create_server+0x74/0x1a4 [nfs]
> > >    [<000000004dc919a1>] nfs3_create_server+0xb/0x25 [nfsv3]
> > > 
> > > It's repeated many times.
> > > 
> > > The workload was an unremarkable software build and regression
> > > test
> > > suite on an NFSv3 mount with RDMA.
> > 
> > Also seeing one of these per NFS mount:
> > 
> > unreferenced object 0xffff888869f39b40 (size 64):
> >   comm "kworker/u28:0", pid 17569, jiffies 4299267916 (age
> > 1592.907s)
> >   hex dump (first 32 bytes):
> >     00 80 53 6d 88 88 ff ff 00 00 00 00 00 00 00
> > 00  ..Sm............
> >     00 48 e2 66 84 88 ff ff 00 00 00 00 00 00 00
> > 00  .H.f............
> >   backtrace:
> >     [<0000000063e652dd>] kmem_cache_alloc_trace+0xed/0x133
> >     [<0000000083b1e912>] qedr_iw_connect+0xf9/0x3c8 [qedr]
> >     [<00000000553be951>] iw_cm_connect+0xd0/0x157 [iw_cm]
> >     [<00000000b086730c>] rdma_connect+0x54e/0x5b0 [rdma_cm]
> >     [<00000000d8af3cf2>] rpcrdma_ep_connect+0x22b/0x360 [rpcrdma]
> >     [<000000006a413c8d>] xprt_rdma_connect_worker+0x24/0x88
> > [rpcrdma]
> >     [<000000001c5b049a>] process_one_work+0x196/0x2c6
> >     [<000000007e3403ba>] worker_thread+0x1ad/0x261
> >     [<000000001daaa973>] kthread+0xf4/0xf9
> >     [<0000000014987b31>] ret_from_fork+0x24/0x30
> > 
> > Looks like this one is not being freed:
> > 
> > 514         ep = kzalloc(sizeof(*ep), GFP_KERNEL);
> > 515         if (!ep)
> > 516                 return -ENOMEM;
> > 
> > 
> > --
> > Chuck Lever
> > 
> > 
> > 

-- 
Doug Ledford <dledford@redhat.com>
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