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Date:   Sun, 15 Jan 2023 13:38:47 +0200
From:   Leon Romanovsky <leon@kernel.org>
To:     Geetha sowjanya <gakula@marvell.com>
Cc:     netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        kuba@kernel.org, pabeni@redhat.com, davem@davemloft.net,
        edumazet@google.com, sbhatta@marvell.com, hkelam@marvell.com,
        sgoutham@marvell.com
Subject: Re: [net PATCH v2] octeontx2-pf: Avoid use of GFP_KERNEL in atomic
 context
Message-ID: <Y8Plx2tH4N3aRMTc@unreal>
References: <20230113061902.6061-1-gakula@marvell.com>
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In-Reply-To: <20230113061902.6061-1-gakula@marvell.com>
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On Fri, Jan 13, 2023 at 11:49:02AM +0530, Geetha sowjanya wrote:
> Using GFP_KERNEL in preemption disable context, causing below warning
> when CONFIG_DEBUG_ATOMIC_SLEEP is enabled.
> 
> [   32.542271] BUG: sleeping function called from invalid context at include/linux/sched/mm.h:274
> [   32.550883] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 1, name: swapper/0
> [   32.558707] preempt_count: 1, expected: 0
> [   32.562710] RCU nest depth: 0, expected: 0
> [   32.566800] CPU: 3 PID: 1 Comm: swapper/0 Tainted: G        W          6.2.0-rc2-00269-gae9dcb91c606 #7
> [   32.576188] Hardware name: Marvell CN106XX board (DT)
> [   32.581232] Call trace:
> [   32.583670]  dump_backtrace.part.0+0xe0/0xf0
> [   32.587937]  show_stack+0x18/0x30
> [   32.591245]  dump_stack_lvl+0x68/0x84
> [   32.594900]  dump_stack+0x18/0x34
> [   32.598206]  __might_resched+0x12c/0x160
> [   32.602122]  __might_sleep+0x48/0xa0
> [   32.605689]  __kmem_cache_alloc_node+0x2b8/0x2e0
> [   32.610301]  __kmalloc+0x58/0x190
> [   32.613610]  otx2_sq_aura_pool_init+0x1a8/0x314
> [   32.618134]  otx2_open+0x1d4/0x9d0
> 
> To avoid use of GFP_ATOMIC for memory allocation, disable preemption 
> after all memory allocation is done.
> 
> Fixes: 4af1b64f80fb ("octeontx2-pf: Fix lmtst ID used in aura free")
> Signed-off-by: Geetha sowjanya <gakula@marvell.com>
> Signed-off-by: Sunil Kovvuri Goutham <sgoutham@marvell.com>
> ---
> v1-v2:
> - Moved get_cpu to avolid use of GFP_ATOMIC. 
> - reworked commit message.
> 
>  drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 

Thanks,
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>