Messages in this thread | | | Date | Mon, 22 May 2017 11:54:26 -0400 (EDT) | Subject | Re: [RFC V1 1/1] net: cdc_ncm: Reduce memory use when kernel memory low | From | David Miller <> |
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From: "Baxter, Jim" <jim_baxter@mentor.com> Date: Mon, 22 May 2017 16:45:42 +0100
> From: David S. Miller (davem@davemloft.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. >> > > 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?
Unfortunately without a real notifier of some sort (there isn't one, and it isn't actually easy to come up with a clean way to do this which is probably why it doesn't exist yet in the first place) I really cannot recommend anything better.
That being said, probably for the time being we should just backoff each and every request, always trying initially to do the higher order thing.
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