Re: [PATCH] sctp: allow sctp_transmit_packet and others to use gfp

[David Miller <davem@davemloft.net>]

From: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Date: Thu, 10 Mar 2016 18:33:07 -0300

> Currently sctp_sendmsg() triggers some calls that will allocate memory
> with GFP_ATOMIC even when not necessary. In the case of
> sctp_packet_transmit it will allocate a linear skb that will be used to
> construct the packet and this may cause sends to fail due to ENOMEM more
> often than anticipated specially with big MTUs.
> 
> This patch thus allows it to inherit gfp flags from upper calls so that
> it can use GFP_KERNEL if it was triggered by a sctp_sendmsg call or
> similar. All others, like retransmits or flushes started from BH, are
> still allocated using GFP_ATOMIC.
> 
> In netperf tests this didn't result in any performance drawbacks when
> memory is not too fragmented and made it trigger ENOMEM way less often.
> 
> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>

Applied, thanks.