[ipc] 5769cf63: LTP semget02 TFAILs

[Fengguang Wu]

Hi Davidlohr,

We noticed LTP test failures

ltp.msgget02.1.TFAIL
ltp.semget02.2.TFAIL
ltp.semget02.3.TFAIL

and the first bad commit is

commit 5769cf6355d87f63906b3e51887eff7017c39217
Author: Davidlohr Bueso <davi...@hp.com>
AuthorDate: Wed Jan 15 16:56:01 2014 +1100
Commit: Stephen Rothwell <s...@canb.auug.org.au>
CommitDate: Wed Jan 15 16:56:01 2014 +1100

ipc: share ids rwsem when possible in ipcget_public

... and rewrite the function. For scenarios where the key is found and
we end up just doing different routinary checks, we can downgrade the
ids->rwsem and share it among concurrent readers. These checks include
the following, which are all safe to share the lock:

ops->more_checks() >> sem_more_checks(), shm_more_checks()
ipc_check_perms() >> ipcperms(),ops->associate() >> [lsm]_[ipctype]_associate()

Signed-off-by: Davidlohr Bueso <davi...@hp.com>
Cc: Aswin Chandramouleeswaran <as...@hp.com>
Cc: Rik van Riel <ri...@redhat.com>
Cc: Manfred Spraul <man...@colorfullife.com>
Signed-off-by: Andrew Morton <ak...@linux-foundation.org>

ipc/util.c | 60 +++++++++++++++++++++++++++++++++---------------------------
1 file changed, 33 insertions(+), 27 deletions(-)

Thanks,
Fengguang
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[Stephen Rothwell]

[ Just adding Andrew to the cc list ]

Cheers,
Stephen Rothwell s...@canb.auug.org.au

[Andrew Morton]

On Fri, 17 Jan 2014 18:24:28 +0800 Fengguang Wu <fenggu...@intel.com> wrote:

> Hi Davidlohr,
>
> We noticed LTP test failures
>
> ltp.msgget02.1.TFAIL
> ltp.semget02.2.TFAIL
> ltp.semget02.3.TFAIL
>
> and the first bad commit is
>
> commit 5769cf6355d87f63906b3e51887eff7017c39217
> Author: Davidlohr Bueso <davi...@hp.com>
> AuthorDate: Wed Jan 15 16:56:01 2014 +1100
> Commit: Stephen Rothwell <s...@canb.auug.org.au>
> CommitDate: Wed Jan 15 16:56:01 2014 +1100
>
> ipc: share ids rwsem when possible in ipcget_public
>

Thanks (a lot). I'll disable that patch for now.