From: Bruce Richardson <bruce.richardson@intel.com>
To: dev@dpdk.org
Subject: Re: [dpdk-dev] [PATCH v7 4/8] vhost: rxtx: use queue id instead of constant ring index
Date: Wed, 21 Oct 2015 16:57:27 +0100 [thread overview]
Message-ID: <5627B5E7.2010105@intel.com> (raw)
In-Reply-To: <2344789.5MT16lH3ET@xps13>
On 21/10/2015 16:52, Thomas Monjalon wrote:
> 2015-10-21 08:47, Stephen Hemminger:
>> On Wed, 21 Oct 2015 09:38:37 +0000
>> "Ananyev, Konstantin" <konstantin.ananyev@intel.com> wrote:
>>> I also don't understand what's wrong with using 'always_inline' here.
>>> As I understand the author wants compiler to *always inline* that function.
>>> So seems perfectly ok to use it here.
>>> As I remember just 'inline' is sort of recommendation that compiler is free to ignore.
>>> Konstantin
>> I follow Linux/Linus advice and resist the urge to add strong inlining.
>> The compiler does a good job of deciding to inline, and many times
>> the reason it chooses for not inlining are quite good like:
>> - the code is on an unlikely branch
>> - register pressure means inlining would mean the code would be worse
>>
>> Therefore my rules are:
>> * only use inline for small functions. Let compiler decide on larger static funcs
>> * write code where most functions are static (localized scope) where compiler
>> can decide
>> * reserve always inline for things that access hardware and would break if not inlined.
> It would be interesting to do some benchmarks with/without "always" keyword
> and add these rules in the coding style guide.
>
Better test would be to measure the hit by explicitly not having it
inlined. You need to know the hit of the compiler making the wrong
choice, even if it normally makes the right one.
Bruce
next prev parent reply other threads:[~2015-10-21 15:57 UTC|newest]
Thread overview: 66+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-21 3:48 [dpdk-dev] [PATCH v7 0/8] vhost-user multiple queues enabling Yuanhan Liu
2015-10-21 3:48 ` [dpdk-dev] [PATCH v7 1/8] vhost-user: add protocol features support Yuanhan Liu
2015-10-22 9:52 ` Xie, Huawei
2015-10-21 3:48 ` [dpdk-dev] [PATCH v7 2/8] vhost-user: add VHOST_USER_GET_QUEUE_NUM message Yuanhan Liu
2015-10-22 9:38 ` Xie, Huawei
2015-10-21 3:48 ` [dpdk-dev] [PATCH v7 3/8] vhost: vring queue setup for multiple queue support Yuanhan Liu
2015-10-21 4:45 ` Stephen Hemminger
2015-10-21 6:52 ` Yuanhan Liu
2015-10-22 9:49 ` Xie, Huawei
2015-10-22 11:30 ` Yuanhan Liu
2015-10-21 3:48 ` [dpdk-dev] [PATCH v7 4/8] vhost: rxtx: use queue id instead of constant ring index Yuanhan Liu
2015-10-21 4:43 ` Stephen Hemminger
2015-10-21 6:54 ` Yuanhan Liu
2015-10-21 7:16 ` Xie, Huawei
2015-10-21 9:38 ` Ananyev, Konstantin
2015-10-21 15:47 ` Stephen Hemminger
2015-10-21 15:52 ` Thomas Monjalon
2015-10-21 15:57 ` Bruce Richardson [this message]
2015-10-21 15:55 ` Bruce Richardson
2015-10-21 16:29 ` Ananyev, Konstantin
2015-10-21 10:31 ` Michael S. Tsirkin
2015-10-21 12:48 ` Yuanhan Liu
2015-10-21 14:26 ` Michael S. Tsirkin
2015-10-21 14:59 ` Yuanhan Liu
2015-10-22 9:49 ` Yuanhan Liu
2015-10-22 11:32 ` Michael S. Tsirkin
2015-10-22 14:07 ` Yuanhan Liu
2015-10-22 14:19 ` Michael S. Tsirkin
2015-10-23 8:02 ` Yuanhan Liu
2015-10-24 2:34 ` Flavio Leitner
2015-10-24 17:47 ` Michael S. Tsirkin
2015-10-28 20:30 ` Flavio Leitner
2015-10-28 21:12 ` Michael S. Tsirkin
2015-11-16 22:20 ` Flavio Leitner
2015-11-17 8:23 ` Michael S. Tsirkin
2015-11-17 9:24 ` Jason Wang
2015-11-17 22:49 ` Flavio Leitner
2015-10-22 7:26 ` Xie, Huawei
2015-10-21 3:48 ` [dpdk-dev] [PATCH v7 5/8] virtio: fix deadloop due to reading virtio_net_config incorrectly Yuanhan Liu
2015-10-21 3:48 ` [dpdk-dev] [PATCH v7 6/8] vhost-user: enable vhost-user multiple queue Yuanhan Liu
2015-10-21 3:48 ` [dpdk-dev] [PATCH v7 7/8] vhost: add VHOST_USER_SET_VRING_ENABLE message Yuanhan Liu
2015-10-21 3:48 ` [dpdk-dev] [PATCH v7 8/8] doc: update release note for vhost-user mq support Yuanhan Liu
2015-10-22 12:35 ` [dpdk-dev] [PATCH v8 0/8] vhost-user multiple queues enabling Yuanhan Liu
2015-10-22 12:35 ` [dpdk-dev] [PATCH v8 1/8] vhost-user: add protocol features support Yuanhan Liu
2015-10-22 12:35 ` [dpdk-dev] [PATCH v8 2/8] vhost-user: add VHOST_USER_GET_QUEUE_NUM message Yuanhan Liu
2015-10-22 12:35 ` [dpdk-dev] [PATCH v8 3/8] vhost: vring queue setup for multiple queue support Yuanhan Liu
2015-10-26 5:24 ` Tetsuya Mukawa
2015-10-26 5:42 ` Yuanhan Liu
2015-10-27 6:20 ` Tetsuya Mukawa
2015-10-27 9:17 ` Michael S. Tsirkin
2015-10-27 9:30 ` Yuanhan Liu
2015-10-27 9:42 ` Michael S. Tsirkin
2015-10-27 9:51 ` Thomas Monjalon
2015-10-27 9:55 ` Michael S. Tsirkin
2015-10-27 10:41 ` Xie, Huawei
2015-10-27 9:53 ` Yuanhan Liu
2015-10-22 12:35 ` [dpdk-dev] [PATCH v8 4/8] vhost: rxtx: use queue id instead of constant ring index Yuanhan Liu
2015-10-22 12:35 ` [dpdk-dev] [PATCH v8 5/8] virtio: fix deadloop due to reading virtio_net_config incorrectly Yuanhan Liu
2015-10-22 12:35 ` [dpdk-dev] [PATCH v8 6/8] vhost: add VHOST_USER_SET_VRING_ENABLE message Yuanhan Liu
2015-10-22 12:35 ` [dpdk-dev] [PATCH v8 7/8] vhost-user: enable vhost-user multiple queue Yuanhan Liu
2015-10-22 12:35 ` [dpdk-dev] [PATCH v8 8/8] doc: update release note for vhost-user mq support Yuanhan Liu
2015-10-26 20:22 ` Thomas Monjalon
2015-10-27 9:38 ` Yuanhan Liu
2015-10-26 1:36 ` [dpdk-dev] [PATCH v8 0/8] vhost-user multiple queues enabling Xie, Huawei
2015-10-26 3:09 ` Yuanhan Liu
2015-10-26 20:26 ` Thomas Monjalon
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=5627B5E7.2010105@intel.com \
--to=bruce.richardson@intel.com \
--cc=dev@dpdk.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).