lkml.org 
[lkml]   [2018]   [May]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: [PATCH v3] mlx4_core: allocate ICM memory in page size chunks
Date


On 5/17/2018 2:14 PM, Eric Dumazet wrote:
> On 05/17/2018 01:53 PM, Qing Huang wrote:
>> When a system is under memory presure (high usage with fragments),
>> the original 256KB ICM chunk allocations will likely trigger kernel
>> memory management to enter slow path doing memory compact/migration
>> ops in order to complete high order memory allocations.
>>
>> When that happens, user processes calling uverb APIs may get stuck
>> for more than 120s easily even though there are a lot of free pages
>> in smaller chunks available in the system.
>>
>> Syslog:
>> ...
>> Dec 10 09:04:51 slcc03db02 kernel: [397078.572732] INFO: task
>> oracle_205573_e:205573 blocked for more than 120 seconds.
>> ...
>>
> NACK on this patch.
>
> You have been asked repeatedly to use kvmalloc()
>
> This is not a minor suggestion.
>
> Take a look athttps://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=d8c13f2271ec5178c52fbde072ec7b562651ed9d

Would you please take a look at how table->icm is being used in the mlx4
driver? It's a meta data used for individual pointer variable referencing,
not as data frag or in/out buffer. It has no need for contiguous phy.
memory.

Thanks.

> And you'll understand some people care about this.
>
> Strongly.
>
> Thanks.
>

\
 
 \ /
  Last update: 2018-05-17 23:45    [W:0.082 / U:1.132 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site