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

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Date:   Mon, 22 May 2017 16:45:42 +0100
From:   "Baxter, Jim" <jim_baxter@...tor.com>
To:     David Miller <davem@...emloft.net>, <bjorn@...k.no>
CC:     <linux-usb@...r.kernel.org>, <netdev@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>, <oliver@...kum.org>
Subject: Re: [RFC V1 1/1] net: cdc_ncm: Reduce memory use when kernel memory
 low

From: David S. Miller (davem@...emloft.net)
Sent: Wed, 17 May 2017 14:18:19 -0400 

> 
> When there isn't memory pressure this will hurt performance of
> course.
> 
> It is a quite common paradigm to back down to 0 order memory requests
> when higher order ones fail, so this isn't such a bad change from the
> perspective.
> 
> However, one negative about it is that when the system is under memory
> stress it doesn't help at all to keep attemping high order allocations
> when the system hasn't recovered yet.  In fact, this can make it
> worse.
> 

Hello David,

Do you think the patch should be modified to extend the length of time
the 0 order memory requests with a time period of 1 minute for example?

Or do you feel the patch is not the correct way this should be performed?

Best regards,
Jim