Re: [RFC V1 1/1] net: cdc_ncm: Reduce memory use when kernel memory low

From	"Baxter, Jim" <jim_baxter@mentor.com>
Newsgroups	linux.kernel
Subject	Re: [RFC V1 1/1] net: cdc_ncm: Reduce memory use when kernel memory low
Date	2017-05-17 13:00 +0200
Message-ID	<tI4Qq-1Z2-9@gated-at.bofh.it> (permalink)
References	<tHOLD-9u-3@gated-at.bofh.it> <tHOLD-9u-1@gated-at.bofh.it> <tHPom-Bv-3@gated-at.bofh.it> <tI1Sz-ck-53@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

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

Thread

[RFC V1 1/1] net: cdc_ncm: Reduce memory use when kernel memory low Jim Baxter <jim_baxter@mentor.com> - 2017-05-16 19:50 +0200
  Re: [RFC V1 1/1] net: cdc_ncm: Reduce memory use when kernel memory low Bjørn Mork <bjorn@mork.no> - 2017-05-16 20:30 +0200
    Re: [RFC V1 1/1] net: cdc_ncm: Reduce memory use when kernel memory  low Oliver Neukum <oneukum@suse.com> - 2017-05-17 09:50 +0200
      Re: [RFC V1 1/1] net: cdc_ncm: Reduce memory use when kernel memory  low "Baxter, Jim" <jim_baxter@mentor.com> - 2017-05-17 13:00 +0200
    Re: [RFC V1 1/1] net: cdc_ncm: Reduce memory use when kernel  memory low David Miller <davem@davemloft.net> - 2017-05-17 20:20 +0200
      Re: [RFC V1 1/1] net: cdc_ncm: Reduce memory use when kernel memory  low Oliver Neukum <oneukum@suse.com> - 2017-05-18 12:10 +0200
      Re: [RFC V1 1/1] net: cdc_ncm: Reduce memory use when kernel memory  low "Baxter, Jim" <jim_baxter@mentor.com> - 2017-05-22 17:50 +0200
        Re: [RFC V1 1/1] net: cdc_ncm: Reduce memory use when kernel  memory low David Miller <davem@davemloft.net> - 2017-05-22 18:00 +0200
          Re: [RFC V1 1/1] net: cdc_ncm: Reduce memory use when kernel memory  low Oliver Neukum <oneukum@suse.com> - 2017-05-23 10:50 +0200
            Re: [RFC V1 1/1] net: cdc_ncm: Reduce memory use when kernel  memory low David Miller <davem@davemloft.net> - 2017-05-23 17:30 +0200
              Re: [RFC V1 1/1] net: cdc_ncm: Reduce memory use when kernel memory  low "Baxter, Jim" <jim_baxter@mentor.com> - 2017-05-23 21:10 +0200
  RE: [RFC V1 1/1] net: cdc_ncm: Reduce memory use when kernel memory  low David Laight <David.Laight@ACULAB.COM> - 2017-05-19 13:20 +0200
    Re: [RFC V1 1/1] net: cdc_ncm: Reduce memory use when kernel memory low Bjørn Mork <bjorn@mork.no> - 2017-05-19 16:00 +0200
      RE: [RFC V1 1/1] net: cdc_ncm: Reduce memory use when kernel memory  low David Laight <David.Laight@ACULAB.COM> - 2017-05-19 16:50 +0200
        Re: [RFC V1 1/1] net: cdc_ncm: Reduce memory use when kernel memory  low Oliver Neukum <oneukum@suse.com> - 2017-05-22 15:30 +0200

csiph-web