Re: REGRESSION f54b311142a92ea2e42598e347b84e1655caf8e3 tcp autocorking slows down iSCSI file system creation by factor of 70 [WAS: 4 TBVMFS creation takes 15 minutes vs 26 seconds]

[Eric Dumazet]

On Sat, 2014-02-08 at 16:00 +0100, Thomas Glanzmann wrote:
> Hello Eric,
> 
> > Idea would be to set this flag when calling sendmsg() of the 48 bytes
> > of the header, and not set it on the sendmsg() of the 512 bytes of the
> > payload.
> 
> I see.
> 
> > iscsi_sw_tcp_xmit_segment() already adds MSG_MORE, but
> > it would be nice to add a new _initial_ flags parameter to
> > iscsi_sw_tcp_xmit_segment()
> 
> This is for the iscsi initiator implementation. I'm interested in iSCSI
> target code, but I already found it and experiemented a little bit, but
> I need to dig deeper if I want to prepare a patch.

Fantastic !

Let me know if you want some help.

Note : We did some patches in the MSG_MORE logic for sendpage(), but in
your case I do not think its related

(git grep -n MSG_SENDPAGE_NOTLAST ) if you are curious


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