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

On Sat, 2014-02-08 at 16:00 +0100, Thomas Glanzmann wrote:

Hello Eric,

quoted

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.

quoted

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