From: Peter Zijlstra <peterz@infradead.org>
To: mingo@kernel.org, tglx@linutronix.de, luto@amacapital.net,
nicolas.pitre@linaro.org, daniel.lezcano@linaro.org,
peterz@infradead.org, umgwanakikbuti@gmail.com
Cc: linux-kernel@vger.kernel.org, Chris Metcalf <cmetcalf@tilera.com>
Subject: [RFC][PATCH 2/8] sched,idle,tile: Switch from TS_POLLING to TIF_POLLING_NRFLAG
Date: Fri, 11 Apr 2014 15:42:45 +0200 [thread overview]
Message-ID: <20140411135218.242750053@infradead.org> (raw)
In-Reply-To: 20140411134243.160989490@infradead.org
[-- Attachment #1: peterz-ts_polling-tile.patch --]
[-- Type: text/plain, Size: 1887 bytes --]
Standardize the idle polling indicator to TIF_POLLING_NRFLAG such that
both TIF_NEED_RESCHED and TIF_POLLING_NRFLAG are in the same word.
This will allow us, using fetch_or(), to both set NEED_RESCHED and
check for POLLING_NRFLAG in a single operation and avoid pointless
wakeups.
Changing from the non-atomic thread_info::status flags to the atomic
thread_info::flags shouldn't be a big issue since most polling state
changes were followed/preceded by a full memory barrier anyway.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
---
arch/tile/include/asm/thread_info.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/arch/tile/include/asm/thread_info.h
+++ b/arch/tile/include/asm/thread_info.h
@@ -129,6 +129,7 @@ extern void _cpu_idle(void);
#define TIF_MEMDIE 7 /* OOM killer at work */
#define TIF_NOTIFY_RESUME 8 /* callback before returning to user */
#define TIF_SYSCALL_TRACEPOINT 9 /* syscall tracepoint instrumentation */
+#define TIF_POLLING_NRFLAG 10 /* idle is polling for TIF_NEED_RESCHED */
#define _TIF_SIGPENDING (1<<TIF_SIGPENDING)
#define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED)
@@ -140,6 +141,7 @@ extern void _cpu_idle(void);
#define _TIF_MEMDIE (1<<TIF_MEMDIE)
#define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME)
#define _TIF_SYSCALL_TRACEPOINT (1<<TIF_SYSCALL_TRACEPOINT)
+#define _TIF_POLLING_NRFLAG (1<<TIF_POLLING_NRFLAG)
/* Work to do on any return to user space. */
#define _TIF_ALLWORK_MASK \
@@ -162,7 +164,6 @@ extern void _cpu_idle(void);
#ifdef __tilegx__
#define TS_COMPAT 0x0001 /* 32-bit compatibility mode */
#endif
-#define TS_POLLING 0x0004 /* in idle loop but not sleeping */
#define TS_RESTORE_SIGMASK 0x0008 /* restore signal mask in do_signal */
#ifndef __ASSEMBLY__
next prev parent reply other threads:[~2014-04-11 13:57 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-11 13:42 [RFC][PATCH 0/8] sched,idle: need resched polling rework Peter Zijlstra
2014-04-11 13:42 ` [RFC][PATCH 1/8] sched,idle,alpha: Switch from TS_POLLING to TIF_POLLING_NRFLAG Peter Zijlstra
2014-04-11 14:38 ` Richard Henderson
2014-04-11 13:42 ` Peter Zijlstra [this message]
2014-04-11 15:15 ` [RFC][PATCH 2/8] sched,idle,tile: " Chris Metcalf
2014-04-11 15:30 ` Peter Zijlstra
2014-04-11 13:42 ` [RFC][PATCH 3/8] sched,idle,ia64: " Peter Zijlstra
2014-04-11 13:42 ` [RFC][PATCH 4/8] sched,idle,x86: " Peter Zijlstra
2014-04-11 13:42 ` [RFC][PATCH 5/8] sched,idle: Remove TS_POLLING support Peter Zijlstra
2014-04-11 13:42 ` [RFC][PATCH 6/8] sched,idle: Avoid spurious wakeup IPIs Peter Zijlstra
2014-04-13 21:41 ` Nicolas Pitre
2014-05-09 13:37 ` James Hogan
2014-05-09 14:15 ` Peter Zijlstra
2014-05-09 14:40 ` Catalin Marinas
2014-05-09 14:50 ` Peter Zijlstra
2014-05-09 14:57 ` Catalin Marinas
2014-05-09 17:02 ` Peter Zijlstra
2014-05-09 17:06 ` Peter Zijlstra
2014-05-09 17:09 ` Catalin Marinas
2014-05-09 17:20 ` Peter Zijlstra
2014-05-19 12:54 ` [tip:sched/arch] arm64: Remove TIF_POLLING_NRFLAG tip-bot for Peter Zijlstra
2014-05-22 12:26 ` [tip:sched/core] " tip-bot for Peter Zijlstra
2014-05-09 14:51 ` [RFC][PATCH 6/8] sched,idle: Avoid spurious wakeup IPIs James Hogan
2014-05-15 9:17 ` James Hogan
2014-05-19 12:54 ` [tip:sched/arch] metag: Remove TIF_POLLING_NRFLAG tip-bot for James Hogan
2014-05-22 12:26 ` [tip:sched/core] " tip-bot for James Hogan
2014-04-11 13:42 ` [RFC][PATCH 7/8] sched,idle: Delay clearing the polling bit Peter Zijlstra
2014-04-13 21:51 ` Nicolas Pitre
2014-04-11 13:42 ` [RFC][PATCH 8/8] sched,idle: Reflow cpuidle_idle_call() Peter Zijlstra
2014-04-13 21:36 ` Nicolas Pitre
2014-04-14 8:59 ` Peter Zijlstra
2014-04-14 9:25 ` Peter Zijlstra
2014-04-14 13:55 ` Nicolas Pitre
2014-04-11 15:00 ` [RFC][PATCH 0/8] sched,idle: need resched polling rework Andy Lutomirski
2014-04-11 15:14 ` Peter Zijlstra
2014-05-22 12:58 ` Peter Zijlstra
2014-05-22 13:09 ` Peter Zijlstra
2014-05-29 0:01 ` Andy Lutomirski
2014-05-29 6:48 ` Peter Zijlstra
2014-06-03 6:40 ` Andy Lutomirski
2014-06-03 6:51 ` Peter Zijlstra
2014-06-03 10:43 ` Peter Zijlstra
2014-06-03 14:02 ` Peter Zijlstra
2014-06-03 16:05 ` Andy Lutomirski
2014-06-03 16:19 ` Peter Zijlstra
2014-06-03 16:52 ` Andy Lutomirski
2014-06-03 17:00 ` Peter Zijlstra
2014-06-03 18:28 ` Peter Zijlstra
2014-06-03 18:44 ` Andy Lutomirski
2014-06-03 20:07 ` Andy Lutomirski
2014-04-12 8:35 ` Mike Galbraith
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