Re: [PATCH 07/13] lightnvm: pblk: Cleanly fail when there is not enough memory

Igor Konopko
2019-03-04T12:46:19Z

On 04.03.2019 10:24, Hans Holmberg wrote:
> Hi Igor,
>
> I think you need to motivate (and document) why each of the new flags
> are needed.

Sure, will add such a description to v2 of the patch.
>
> Thanks,
> Hans
>
> On Mon, Mar 4, 2019 at 8:53 AM Javier González <javier@javigon.com> wrote:
>>
>>> On 27 Feb 2019, at 18.14, Igor Konopko <igor.j.konopko@intel.com> wrote:
>>>
>>> L2P table can be huge in many cases, since
>>> it typically requires 1GB of DRAM for 1TB
>>> of drive. When there is not enough memory
>>> available, OOM killer turns on and kills
>>> random processes, which can be very annoying
>>> for users. This patch changes the flag for
>>> L2P table allocation on order to handle this
>>> situation in more user friendly way
>>>
>>> Signed-off-by: Igor Konopko <igor.j.konopko@intel.com>
>>> ---
>>> drivers/lightnvm/pblk-init.c | 9 +++++++--
>>> 1 file changed, 7 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/lightnvm/pblk-init.c b/drivers/lightnvm/pblk-init.c
>>> index 8b643d0bffae..e553105b7ba1 100644
>>> --- a/drivers/lightnvm/pblk-init.c
>>> +++ b/drivers/lightnvm/pblk-init.c
>>> @@ -164,9 +164,14 @@ static int pblk_l2p_init(struct pblk *pblk, bool factory_init)
>>> int ret = 0;
>>>
>>> map_size = pblk_trans_map_size(pblk);
>>> - pblk->trans_map = vmalloc(map_size);
>>> - if (!pblk->trans_map)
>>> + pblk->trans_map = __vmalloc(map_size, GFP_KERNEL | __GFP_NOWARN
>>> + | __GFP_RETRY_MAYFAIL | __GFP_HIGHMEM,
>>> + PAGE_KERNEL);
>>> + if (!pblk->trans_map) {
>>> + pblk_err(pblk, "failed to allocate L2P (need %ld of memory)\n",
>>> + map_size);
>>> return -ENOMEM;
>>> + }
>>>
>>> pblk_ppa_set_empty(&ppa);
>>>
>>> --
>>> 2.17.1
>>
>> Is there any extra consideration we should take when enabling high
>> memory for the L2P table? If not, looks good to me.
>>
>> Reviewed-by: Javier González <javier@javigon.com>