netdev.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Qing Huang <qing.huang@oracle.com>
To: Eric Dumazet <eric.dumazet@gmail.com>,
	tariqt@mellanox.com, davem@davemloft.net,
	haakon.bugge@oracle.com, yanjun.zhu@oracle.com
Cc: netdev@vger.kernel.org, linux-rdma@vger.kernel.org,
	linux-kernel@vger.kernel.org, gi-oh.kim@profitbricks.com
Subject: Re: [PATCH v3] mlx4_core: allocate ICM memory in page size chunks
Date: Thu, 17 May 2018 14:45:20 -0700	[thread overview]
Message-ID: <19b7818e-16f6-2349-dc34-245c2f215f6f@oracle.com> (raw)
In-Reply-To: <e6c470f0-f2ae-5efd-09ed-0c9562a4a764@gmail.com>



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.
>

  reply	other threads:[~2018-05-17 21:45 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-17 20:53 [PATCH v3] mlx4_core: allocate ICM memory in page size chunks Qing Huang
2018-05-17 21:14 ` Eric Dumazet
2018-05-17 21:45   ` Qing Huang [this message]
2018-05-22 15:33     ` Tariq Toukan
2018-05-23  1:41       ` Qing Huang

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=19b7818e-16f6-2349-dc34-245c2f215f6f@oracle.com \
    --to=qing.huang@oracle.com \
    --cc=davem@davemloft.net \
    --cc=eric.dumazet@gmail.com \
    --cc=gi-oh.kim@profitbricks.com \
    --cc=haakon.bugge@oracle.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-rdma@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=tariqt@mellanox.com \
    --cc=yanjun.zhu@oracle.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).