From: David Laight <David.Laight@ACULAB.COM>
To: 'Xin Long' <lucien.xin@gmail.com>,
Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Cc: Neil Horman <nhorman@tuxdriver.com>,
network dev <netdev@vger.kernel.org>,
"linux-sctp@vger.kernel.org" <linux-sctp@vger.kernel.org>,
"davem@davemloft.net" <davem@davemloft.net>
Subject: RE: [PATCHv2 net-next 04/12] sctp: implement make_datafrag for sctp_stream_interleave
Date: Fri, 8 Dec 2017 16:22:05 +0000 [thread overview]
Message-ID: <27aff622f1574b329e18ba21922f6e7e@AcuMS.aculab.com> (raw)
In-Reply-To: <CADvbK_ckOgH9vzXVzckEtWAkJaYn9wuhJtZ+qpzep2T6C8Wung@mail.gmail.com>
From: Xin Long
> Sent: 08 December 2017 16:18
>
...
> >> Alternatively you could preform the dereference in two steps (i.e. declare an si
> >> pointer on the stack and set it equal to asoc->stream.si, then deref
> >> si->make_datafrag at call time. That will at least give the compiler an
> >> opportunity to preload the first pointer.
You want to save the function pointer itself.
...
> Another small difference:
> as you can see, comparing to (X), (Y) is using 0x28(%rsp) in the loop,
> instead of %r13.
>
> So that's what I can see from the related generated code.
> If 0x848(%r13) is not worse than 0x28(%rsp) for cpu, I think
> asoc->stream.si->make_datafrag() is even better. No ?
That code must have far too many life local variables.
Otherwise there's be a caller saved register available.
David
next prev parent reply other threads:[~2017-12-08 16:21 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-08 13:03 [PATCHv2 net-next 00/12] sctp: Implement Stream Interleave: The I-DATA Chunk Supporting User Message Interleaving Xin Long
2017-12-08 13:03 ` [PATCHv2 net-next 01/12] sctp: add stream interleave enable members and sockopt Xin Long
2017-12-08 13:03 ` [PATCHv2 net-next 02/12] sctp: add asoc intl_enable negotiation during 4 shakehands Xin Long
2017-12-08 13:04 ` [PATCHv2 net-next 03/12] sctp: add basic structures and make chunk function for idata Xin Long
2017-12-08 13:04 ` [PATCHv2 net-next 04/12] sctp: implement make_datafrag for sctp_stream_interleave Xin Long
2017-12-08 13:04 ` [PATCHv2 net-next 05/12] sctp: implement assign_number " Xin Long
2017-12-08 13:04 ` [PATCHv2 net-next 06/12] sctp: implement validate_data " Xin Long
2017-12-08 13:04 ` [PATCHv2 net-next 07/12] sctp: implement ulpevent_data " Xin Long
2017-12-08 13:04 ` [PATCHv2 net-next 08/12] sctp: implement enqueue_event " Xin Long
2017-12-08 13:04 ` [PATCHv2 net-next 09/12] sctp: implement renege_events " Xin Long
2017-12-08 13:04 ` [PATCHv2 net-next 10/12] sctp: implement start_pd " Xin Long
2017-12-08 13:04 ` [PATCHv2 net-next 11/12] sctp: implement abort_pd " Xin Long
2017-12-08 13:04 ` [PATCHv2 net-next 12/12] sctp: add support for the process of unordered idata Xin Long
2017-12-08 14:06 ` [PATCHv2 net-next 04/12] sctp: implement make_datafrag for sctp_stream_interleave David Laight
2017-12-08 14:56 ` Marcelo Ricardo Leitner
2017-12-08 15:01 ` David Laight
2017-12-08 15:15 ` 'Marcelo Ricardo Leitner'
2017-12-08 15:32 ` David Laight
2017-12-08 16:02 ` 'Marcelo Ricardo Leitner'
2017-12-08 15:37 ` Neil Horman
2017-12-08 16:00 ` Marcelo Ricardo Leitner
2017-12-08 16:04 ` David Laight
2017-12-08 16:08 ` Neil Horman
2017-12-08 20:37 ` 'Marcelo Ricardo Leitner'
2017-12-08 16:17 ` Xin Long
2017-12-08 16:22 ` David Laight [this message]
2017-12-08 17:23 ` Xin Long
2017-12-08 17:29 ` David Laight
2017-12-08 17:37 ` Xin Long
2017-12-11 16:23 ` [PATCHv2 net-next 00/12] sctp: Implement Stream Interleave: The I-DATA Chunk Supporting User Message Interleaving David Miller
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