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From: Eric Dumazet <eric.dumazet@gmail.com>
To: Andrey Ryabinin <aryabinin@virtuozzo.com>,
	"David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>,
	Mel Gorman <mgorman@techsingularity.net>,
	Willem de Bruijn <willemb@google.com>,
	Florian Westphal <fw@strlen.de>,
	linux-kernel@vger.kernel.org, netdev@vger.kernel.org
Subject: Re: [PATCH 1/4] net/skbuff: don't waste memory reserves
Date: Fri, 19 Apr 2019 06:41:37 -0700	[thread overview]
Message-ID: <a80606cf-3076-b01d-0442-ccff3c462276@gmail.com> (raw)
In-Reply-To: <c2c270d9-29c0-b993-84c5-4c994608f7c8@virtuozzo.com>



On 04/19/2019 06:17 AM, Andrey Ryabinin wrote:
> 

> I don't see why that would be a problem. If refill failed because we didn't have
> access to reserves, then there going to be an another refill attempt, right?
> And the next refill attempt will be with access to the reserves if memalloc socket was created.
> We can't predict the future, so until the memalloc socket appeared we must assume that those
> RX ring buffers won't be used to reclaim memory (and that is actually true in 99% of cases).
> 

I just said that the alloc might be attempted "in the past"

Yes, we can not predict the future, this is why we need to access the reserve _now_ and not
at the time the packet is received.

The 'being true in 99% of cases' argument is not really convincing.

You want the NIC to be ready to receive packets even before sk_memalloc_socks() becomes true.

If a NIC driver has a bug, please fix it.

  parent reply	other threads:[~2019-04-19 18:55 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-04-18 18:05 [PATCH 1/4] net/skbuff: don't waste memory reserves Andrey Ryabinin
2019-04-18 18:05 ` [PATCH 2/4] net/skbuff: warn if kmalloc_reserve() fails to allocate memory Andrey Ryabinin
2019-04-18 18:05 ` [PATCH 3/4] net/skbuff: remove unused skb_propagate_pfmemalloc() Andrey Ryabinin
2019-04-18 18:05 ` [PATCH 4/4] net/skbuff: kmalloc_reserve(): remove unused argument Andrey Ryabinin
2019-04-18 18:55 ` [PATCH 1/4] net/skbuff: don't waste memory reserves Eric Dumazet
2019-04-18 18:56   ` David Miller
2019-04-19 13:17   ` Andrey Ryabinin
2019-04-19 13:36     ` Eric Dumazet
2019-04-19 13:41     ` Eric Dumazet [this message]
2019-04-19 16:25       ` Andrey Ryabinin
2019-04-19 16:27         ` Eric Dumazet

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