linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: "Baxter, Jim" <jim_baxter@mentor.com>
To: "Oliver Neukum" <oneukum@suse.com>, "Bjørn Mork" <bjorn@mork.no>
Cc: <linux-kernel@vger.kernel.org>, <linux-usb@vger.kernel.org>,
	<netdev@vger.kernel.org>
Subject: Re: [RFC V1 1/1] net: cdc_ncm: Reduce memory use when kernel memory low
Date: Wed, 17 May 2017 11:56:05 +0100	[thread overview]
Message-ID: <b8114201-8beb-23ea-479a-9db006d4a668@mentor.com> (raw)
In-Reply-To: <1495007060.30577.8.camel@suse.com>

From: Oliver Neukum (oneukum@suse.com) Sent: Wed, 17 May 2017 09:44:20 +0200 

> Am Dienstag, den 16.05.2017, 20:24 +0200 schrieb Bjørn Mork:
>>
>> I must say that I don't like the additional complexity added here.  If
>> there are memory issues and you can reduce the buffer size to
>> USB_CDC_NCM_NTB_MIN_OUT_SIZE, then why don't you just set a lower tx_max
>> buffer size in the first place?
>>
>>   echo 2048 > /sys/class/net/wwan0/cdc_ncm/tx_max
>>

Hi

The issue is we need the higher performance for Mirrorlink to be able to
work correctly. The low memory situation only occurs very occasionally and
once the kernel has run compaction if this issue occurs again it will be
many hours later.

> 
> Hi,
> 
> that would hurt performance across the board though.
> Can we trigger memory compactation earlier?
> 
> 	Regards
> 		Oliver
> 

We initially tried increasing the vm.min_free_kbytes but the value needed to address
the problem was around 65536 which then meant some other applications were unable to
run due to there not being enough free memory.
The i.MX6 based system has 863MB of RAM in total.

Regards,
Jim

  reply	other threads:[~2017-05-17 10:56 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-05-16 17:41 [RFC V1 0/1] Reduce cdc_ncm memory use when kernel memory low Jim Baxter
2017-05-16 17:41 ` [RFC V1 1/1] net: cdc_ncm: Reduce " Jim Baxter
2017-05-16 18:24   ` Bjørn Mork
2017-05-17  7:44     ` Oliver Neukum
2017-05-17 10:56       ` Baxter, Jim [this message]
2017-05-17 18:18     ` David Miller
2017-05-18 10:01       ` Oliver Neukum
2017-05-22 15:45       ` Baxter, Jim
2017-05-22 15:54         ` David Miller
2017-05-23  8:42           ` Oliver Neukum
2017-05-23 15:26             ` David Miller
2017-05-23 19:06               ` Baxter, Jim
     [not found]                 ` <1497263047.15677.13.camel@suse.com>
2017-06-12 12:32                   ` Baxter, Jim
2017-05-19 11:10   ` David Laight
2017-05-19 13:55     ` Bjørn Mork
2017-05-19 14:46       ` David Laight
2017-05-22 13:27         ` Oliver Neukum

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=b8114201-8beb-23ea-479a-9db006d4a668@mentor.com \
    --to=jim_baxter@mentor.com \
    --cc=bjorn@mork.no \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-usb@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=oneukum@suse.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).