From: zhouchuangao <zhouchuangao@vivo.com>
To: Peter Zijlstra <peterz@infradead.org>,
Joerg Roedel <jroedel@suse.de>, Ingo Molnar <mingo@kernel.org>,
zhouchuangao <zhouchuangao@vivo.com>,
"Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
linux-kernel@vger.kernel.org
Subject: [PATCH] kernel/notifier: Use BUG_ON instead of if condition followed by BUG
Date: Fri, 23 Apr 2021 00:56:34 -0700 [thread overview]
Message-ID: <1619164597-69309-1-git-send-email-zhouchuangao@vivo.com> (raw)
BUG_ON uses unlikely in if(). Through disassembly, we can see that
brk #0x800 is compiled to the end of the function.
As you can see below:
......
ffffff8008660bec: d65f03c0 ret
ffffff8008660bf0: d4210000 brk #0x800
Usually, the condition in if () is not satisfied. For the
multi-stage pipeline, we do not need to perform fetch decode
and excute operation on brk instruction.
In my opinion, this can improve the efficiency of the
multi-stage pipeline.
Signed-off-by: zhouchuangao <zhouchuangao@vivo.com>
---
kernel/notifier.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/kernel/notifier.c b/kernel/notifier.c
index 1b019cb..2b0ed7d 100644
--- a/kernel/notifier.c
+++ b/kernel/notifier.c
@@ -522,8 +522,7 @@ EXPORT_SYMBOL_GPL(srcu_notifier_call_chain);
void srcu_init_notifier_head(struct srcu_notifier_head *nh)
{
mutex_init(&nh->mutex);
- if (init_srcu_struct(&nh->srcu) < 0)
- BUG();
+ BUG_ON(init_srcu_struct(&nh->srcu) < 0);
nh->head = NULL;
}
EXPORT_SYMBOL_GPL(srcu_init_notifier_head);
--
2.7.4
reply other threads:[~2021-04-23 7:56 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
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=1619164597-69309-1-git-send-email-zhouchuangao@vivo.com \
--to=zhouchuangao@vivo.com \
--cc=jroedel@suse.de \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=peterz@infradead.org \
--cc=rafael.j.wysocki@intel.com \
/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).