mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: linux-kernel@vger.kernel.org
Cc: mingo@kernel.org, laijs@cn.fujitsu.com, dipankar@in.ibm.com,
	akpm@linux-foundation.org, mathieu.desnoyers@efficios.com,
	josh@joshtriplett.org, tglx@linutronix.de, peterz@infradead.org,
	rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com,
	dvhart@linux.intel.com, fweisbec@gmail.com, oleg@redhat.com,
	bobby.prani@gmail.com, Alexander Gordeev <agordeev@redhat.com>,
	"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Subject: [PATCH tip/core/rcu 2/2] rcu: Remove fastpath from __rcu_process_callbacks()
Date: Tue,  3 Mar 2015 09:53:36 -0800	[thread overview]
Message-ID: <1425405216-19953-2-git-send-email-paulmck@linux.vnet.ibm.com> (raw)
In-Reply-To: <1425405216-19953-1-git-send-email-paulmck@linux.vnet.ibm.com>

From: Alexander Gordeev <agordeev@redhat.com>

The standard code path accommodates a condition when no
RCU callbacks are ready to invoke. Since size of the code
is a priority for tiny RCU, remove the fast path.

Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
---
 kernel/rcu/tiny.c | 11 -----------
 1 file changed, 11 deletions(-)

diff --git a/kernel/rcu/tiny.c b/kernel/rcu/tiny.c
index d4e7fe5f3baf..069742d61c68 100644
--- a/kernel/rcu/tiny.c
+++ b/kernel/rcu/tiny.c
@@ -168,17 +168,6 @@ static void __rcu_process_callbacks(struct rcu_ctrlblk *rcp)
 	unsigned long flags;
 	RCU_TRACE(int cb_count = 0);
 
-	/* If no RCU callbacks ready to invoke, just return. */
-	if (&rcp->rcucblist == rcp->donetail) {
-		RCU_TRACE(trace_rcu_batch_start(rcp->name, 0, 0, -1));
-		RCU_TRACE(trace_rcu_batch_end(rcp->name, 0,
-					      !!ACCESS_ONCE(rcp->rcucblist),
-					      need_resched(),
-					      is_idle_task(current),
-					      false));
-		return;
-	}
-
 	/* Move the ready-to-invoke callbacks to a local list. */
 	local_irq_save(flags);
 	RCU_TRACE(trace_rcu_batch_start(rcp->name, 0, rcp->qlen, -1));
-- 
1.8.1.5


      reply	other threads:[~2015-03-03 17:54 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-03-03 17:53 [PATCH tip/core/rcu 0/2] Tiny RCU updates for v4.1 Paul E. McKenney
2015-03-03 17:53 ` [PATCH tip/core/rcu 1/2] rcu: Remove unnecessary condition check in rcu_qsctr_help() Paul E. McKenney
2015-03-03 17:53   ` Paul E. McKenney [this message]

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=1425405216-19953-2-git-send-email-paulmck@linux.vnet.ibm.com \
    --to=paulmck@linux.vnet.ibm.com \
    --cc=agordeev@redhat.com \
    --cc=akpm@linux-foundation.org \
    --cc=bobby.prani@gmail.com \
    --cc=dhowells@redhat.com \
    --cc=dipankar@in.ibm.com \
    --cc=dvhart@linux.intel.com \
    --cc=edumazet@google.com \
    --cc=fweisbec@gmail.com \
    --cc=josh@joshtriplett.org \
    --cc=laijs@cn.fujitsu.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mathieu.desnoyers@efficios.com \
    --cc=mingo@kernel.org \
    --cc=oleg@redhat.com \
    --cc=peterz@infradead.org \
    --cc=rostedt@goodmis.org \
    --cc=tglx@linutronix.de \
    /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

Powered by JetHome