Re: [net PATCH] octeontx2-pf: Use GFP_ATOMIC in atomic context

[Geethasowjanya Akula <gakula@marvell.com>]

-----Original Message-----
From: Leon Romanovsky <leon@kernel.org>
Sent: Sunday, January 8, 2023 6:39 PM
To: Geethasowjanya Akula <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; Subbaraya Sundeep Bhatta <sbhatta@marvell.com>; Hariprasad Kelam <hkelam@marvell.com>; Sunil Kovvuri Goutham <sgoutham@marvell.com>
Subject: [EXT] Re: [net PATCH] octeontx2-pf: Use GFP_ATOMIC in atomic context

External Email

----------------------------------------------------------------------
On Sat, Jan 07, 2023 at 10:11:39AM +0530, Geetha sowjanya wrote:
>> Use GFP_ATOMIC flag instead of GFP_KERNEL while allocating memory in 
>> atomic context.

>Awesome, but the changed functions don't run in atomic context.

drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.c
    1368         /* Flush accumulated messages */
    1369         err = otx2_sync_mbox_msg(&pfvf->mbox);
    1370         if (err)
    1371                 goto fail;
    1372
    1373         get_cpu();
                 ^^^^^^^^^
The get_cpu() disables preemption. 

    1374         /* Allocate pointers and free them to aura/pool */
    1375         for (qidx = 0; qidx < hw->tot_tx_queues; qidx++) {
    1376                 pool_id = otx2_get_pool_idx(pfvf, AURA_NIX_SQ, qidx);
    1377                 pool = &pfvf->qset.pool[pool_id];
    1378
    1379                 sq = &qset->sq[qidx];
    1380                 sq->sqb_count = 0;
    1381                 sq->sqb_ptrs = kcalloc(num_sqbs, sizeof(*sq->sqb_ptrs), GFP_ATOMIC);

>> Fixes: 4af1b64f80fb ("octeontx2-pf: Fix lmtst ID used in aura free")
>> Signed-off-by: Sunil Goutham <sgoutham@marvell.com>
>> Signed-off-by: Geetha sowjanya <gakula@marvell.com>
>> ---
>>  drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.c | 4 ++--
>>  1 file changed, 2 insertions(+), 2 deletions(-)
>> 
>> diff --git a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.c
>> b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.c
>> index 88f8772a61cd..12e4365d53df 100644
>> --- a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.c
>> +++ b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.c
>> @@ -886,7 +886,7 @@ static int otx2_sq_init(struct otx2_nic *pfvf, u16 qidx, u16 sqb_aura)
>>  	}
>>  
>>  	sq->sqe_base = sq->sqe->base;
>> -	sq->sg = kcalloc(qset->sqe_cnt, sizeof(struct sg_list), GFP_KERNEL);
>> +	sq->sg = kcalloc(qset->sqe_cnt, sizeof(struct sg_list), 
>> +GFP_ATOMIC);
>>  	if (!sq->sg)
>>  		return -ENOMEM;
>>  
>> @@ -1378,7 +1378,7 @@ int otx2_sq_aura_pool_init(struct otx2_nic
>> *pfvf)
>>  
>>  		sq = &qset->sq[qidx];
>>  		sq->sqb_count = 0;
>> -		sq->sqb_ptrs = kcalloc(num_sqbs, sizeof(*sq->sqb_ptrs), GFP_KERNEL);
>> +		sq->sqb_ptrs = kcalloc(num_sqbs, sizeof(*sq->sqb_ptrs), 
>> +GFP_ATOMIC);
>>  		if (!sq->sqb_ptrs) {
>>  			err = -ENOMEM;
>>  			goto err_mem;
>> --
>> 2.25.1
>>