From: Frank Rowand <frank.rowand@am.sony.com> To: Thomas Gleixner <tglx@linutronix.de> Cc: LKML <linux-kernel@vger.kernel.org>, "linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>, Peter Zijlstra <peterz@infradead.org>, Rusty Russell <rusty@rustcorp.com.au>, "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>, Ingo Molnar <mingo@kernel.org>, "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>, Matt Turner <mattst88@gmail.com>, Russell King <linux@arm.linux.org.uk>, Mike Frysinger <vapier@gentoo.org>, Jesper Nilsson <jesper.nilsson@axis.com>, Richard Kuo <rkuo@codeaurora.org>, Tony Luck <tony.luck@intel.com>, Hirokazu Takata <takata@linux-m32r.org>, Ralf Baechle <ralf@linux-mips.org>, David Howells <dhowells@redhat.com>, "James E.J. Bottomley" <jejb@parisc-linux.org>, Benjamin Herrenschmidt <benh@kernel.crashing.org>, Martin Schwidefsky <schwidefsky@de.ibm.com>, Paul Mundt <lethal@linux-sh.org>, "David S. Miller" <davem@davemloft.net>, Chris Metcalf <cmetcalf@tilera.com>, Richard Weinberger <richard@nod.at>, "x86@kernel.org" <x86@kernel.org> Subject: Re: [patch 04/18] smp: Provide generic idle thread allocation Date: Fri, 20 Apr 2012 19:25:25 -0700 [thread overview] Message-ID: <4F921A95.3030805@am.sony.com> (raw) In-Reply-To: <20120420124557.102478630@linutronix.de> On 04/20/12 06:05, Thomas Gleixner wrote: > All SMP architectures have magic to fork the idle task and to store it > for reusage when cpu hotplug is enabled. Provide a generic > infrastructure for it. > > Create/reinit the idle thread for the cpu which is brought up in the > generic code and hand the thread pointer to the architecture code via > __cpu_up(). > > Note, that fork_idle() is called via a workqueue, because this > guarantees that the idle thread does not get a reference to a user > space VM. This can happen when the boot process did not bring up all > possible cpus and a later cpu_up() is initiated via the sysfs > interface. In that case fork_idle() would be called in the context of > the user space task and take a reference on the user space VM. > > Signed-off-by: Thomas Gleixner <tglx@linutronix.de> > Cc: Matt Turner <mattst88@gmail.com> > Cc: Russell King <linux@arm.linux.org.uk> > Cc: Mike Frysinger <vapier@gentoo.org> > Cc: Jesper Nilsson <jesper.nilsson@axis.com> > Cc: Richard Kuo <rkuo@codeaurora.org> > Cc: Tony Luck <tony.luck@intel.com> > Cc: Hirokazu Takata <takata@linux-m32r.org> > Cc: Ralf Baechle <ralf@linux-mips.org> > Cc: David Howells <dhowells@redhat.com> > Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> > Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> > Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> > Cc: Paul Mundt <lethal@linux-sh.org> > Cc: "David S. Miller" <davem@davemloft.net> > Cc: Chris Metcalf <cmetcalf@tilera.com> > Cc: Richard Weinberger <richard@nod.at> > Cc: x86@kernel.org > --- > arch/Kconfig | 3 + > kernel/cpu.c | 2 - > kernel/sched/core.c | 2 + > kernel/smpboot.c | 83 ++++++++++++++++++++++++++++++++++++++++++++++++++++ > kernel/smpboot.h | 10 ++++++ > 5 files changed, 99 insertions(+), 1 deletion(-) > > Index: linux-2.6/arch/Kconfig > =================================================================== > --- linux-2.6.orig/arch/Kconfig > +++ linux-2.6/arch/Kconfig > @@ -145,6 +145,9 @@ config HAVE_DMA_ATTRS > config USE_GENERIC_SMP_HELPERS > bool > > +config GENERIC_SMP_IDLE_THREAD > + bool ^^^^^ This _appears_ to be spaces instead of a tab. Hopefully not a false alarm, I know my mail servers randomly change tabs to spaces, just to mess with me, but I double checked at the lkml archive. > + > config HAVE_REGS_AND_STACK_ACCESS_API > bool > help < snip > - Frank
WARNING: multiple messages have this Message-ID (diff)
From: Frank Rowand <frank.rowand@am.sony.com> To: Thomas Gleixner <tglx@linutronix.de> Cc: LKML <linux-kernel@vger.kernel.org>, "linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>, Peter Zijlstra <peterz@infradead.org>, Rusty Russell <rusty@rustcorp.com.au>, "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>, Ingo Molnar <mingo@kernel.org>, "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>, Matt Turner <mattst88@gmail.com>, Russell King <linux@arm.linux.org.uk>, Mike Frysinger <vapier@gentoo.org>, Jesper Nilsson <jesper.nilsson@axis.com>, Richard Kuo <rkuo@codeaurora.org>, Tony Luck <tony.luck@intel.com>, Hirokazu Takata <takata@linux-m32r.org>, Ralf Baechle <ralf@linux-mips.org>, David Howells <dhowells@redhat.com>, "James E.J. Bottomley" <jejb@parisc-linux.org>, Benjamin Herrenschmidt <benh@kernel.crashing.org>, Martin Schwidefsky <schwidefsky@de.ibm.com>, Paul Mundt <lethal@linux-sh.org>, "David S. Miller" <davem@davemloft.net>, Chris Subject: Re: [patch 04/18] smp: Provide generic idle thread allocation Date: Fri, 20 Apr 2012 19:25:25 -0700 [thread overview] Message-ID: <4F921A95.3030805@am.sony.com> (raw) In-Reply-To: <20120420124557.102478630@linutronix.de> On 04/20/12 06:05, Thomas Gleixner wrote: > All SMP architectures have magic to fork the idle task and to store it > for reusage when cpu hotplug is enabled. Provide a generic > infrastructure for it. > > Create/reinit the idle thread for the cpu which is brought up in the > generic code and hand the thread pointer to the architecture code via > __cpu_up(). > > Note, that fork_idle() is called via a workqueue, because this > guarantees that the idle thread does not get a reference to a user > space VM. This can happen when the boot process did not bring up all > possible cpus and a later cpu_up() is initiated via the sysfs > interface. In that case fork_idle() would be called in the context of > the user space task and take a reference on the user space VM. > > Signed-off-by: Thomas Gleixner <tglx@linutronix.de> > Cc: Matt Turner <mattst88@gmail.com> > Cc: Russell King <linux@arm.linux.org.uk> > Cc: Mike Frysinger <vapier@gentoo.org> > Cc: Jesper Nilsson <jesper.nilsson@axis.com> > Cc: Richard Kuo <rkuo@codeaurora.org> > Cc: Tony Luck <tony.luck@intel.com> > Cc: Hirokazu Takata <takata@linux-m32r.org> > Cc: Ralf Baechle <ralf@linux-mips.org> > Cc: David Howells <dhowells@redhat.com> > Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> > Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> > Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> > Cc: Paul Mundt <lethal@linux-sh.org> > Cc: "David S. Miller" <davem@davemloft.net> > Cc: Chris Metcalf <cmetcalf@tilera.com> > Cc: Richard Weinberger <richard@nod.at> > Cc: x86@kernel.org > --- > arch/Kconfig | 3 + > kernel/cpu.c | 2 - > kernel/sched/core.c | 2 + > kernel/smpboot.c | 83 ++++++++++++++++++++++++++++++++++++++++++++++++++++ > kernel/smpboot.h | 10 ++++++ > 5 files changed, 99 insertions(+), 1 deletion(-) > > Index: linux-2.6/arch/Kconfig > =================================================================== > --- linux-2.6.orig/arch/Kconfig > +++ linux-2.6/arch/Kconfig > @@ -145,6 +145,9 @@ config HAVE_DMA_ATTRS > config USE_GENERIC_SMP_HELPERS > bool > > +config GENERIC_SMP_IDLE_THREAD > + bool ^^^^^ This _appears_ to be spaces instead of a tab. Hopefully not a false alarm, I know my mail servers randomly change tabs to spaces, just to mess with me, but I double checked at the lkml archive. > + > config HAVE_REGS_AND_STACK_ACCESS_API > bool > help < snip > - Frank
next prev parent reply other threads:[~2012-04-21 2:25 UTC|newest] Thread overview: 87+ messages / expand[flat|nested] mbox.gz Atom feed top 2012-04-20 13:05 [patch 00/18] SMP: Boot and CPU hotplug refactoring - Part 1 Thomas Gleixner 2012-04-20 13:05 ` [patch 01/18] m32r: Remove pointless function prototypes Thomas Gleixner 2012-04-28 9:01 ` [tip:smp/hotplug] " tip-bot for Thomas Gleixner 2012-04-20 13:05 ` [patch 02/18] smp: Add task_struct argument to __cpu_up() Thomas Gleixner 2012-04-20 13:05 ` Thomas Gleixner 2012-04-23 7:58 ` Jesper Nilsson 2012-04-23 7:58 ` Jesper Nilsson 2012-04-28 9:02 ` [tip:smp/hotplug] " tip-bot for Thomas Gleixner 2012-04-20 13:05 ` [patch 03/18] smp: Add generic smpboot facility Thomas Gleixner 2012-04-20 13:05 ` Thomas Gleixner 2012-04-20 20:07 ` Yinghai Lu 2012-04-20 20:07 ` Yinghai Lu 2012-04-21 2:07 ` Stephen Rothwell 2012-04-21 2:07 ` Stephen Rothwell 2012-04-28 9:04 ` [tip:smp/hotplug] " tip-bot for Thomas Gleixner 2012-04-20 13:05 ` [patch 04/18] smp: Provide generic idle thread allocation Thomas Gleixner 2012-04-20 13:05 ` Thomas Gleixner 2012-04-20 16:21 ` Sam Ravnborg 2012-04-20 16:21 ` Sam Ravnborg 2012-04-20 18:55 ` Thomas Gleixner 2012-04-20 18:55 ` Thomas Gleixner 2012-04-21 2:20 ` Stephen Rothwell 2012-04-21 2:20 ` Stephen Rothwell 2012-04-21 2:25 ` Frank Rowand [this message] 2012-04-21 2:25 ` Frank Rowand 2012-04-28 9:05 ` [tip:smp/hotplug] " tip-bot for Thomas Gleixner 2012-04-20 13:05 ` [patch 05/18] x86: Add task_struct argument to smp_ops.cpu_up Thomas Gleixner 2012-04-28 9:05 ` [tip:smp/hotplug] " tip-bot for Thomas Gleixner 2012-04-20 13:05 ` [patch 06/18] x86: Use generic idle thread allocation Thomas Gleixner 2012-04-28 9:06 ` [tip:smp/hotplug] " tip-bot for Thomas Gleixner 2012-04-20 13:05 ` [patch 07/18] powerpc: " Thomas Gleixner 2012-04-28 9:07 ` [tip:smp/hotplug] " tip-bot for Thomas Gleixner 2012-04-28 22:51 ` Benjamin Herrenschmidt 2012-04-20 13:05 ` [patch 08/18] ia64: " Thomas Gleixner 2012-04-28 9:08 ` [tip:smp/hotplug] " tip-bot for Thomas Gleixner 2012-04-20 13:05 ` [patch 09/18] arm: " Thomas Gleixner 2012-04-28 9:09 ` [tip:smp/hotplug] " tip-bot for Thomas Gleixner 2012-04-20 13:05 ` [patch 11/18] hexagon: " Thomas Gleixner 2012-04-24 16:47 ` Richard Kuo 2012-04-28 9:10 ` [tip:smp/hotplug] " tip-bot for Thomas Gleixner 2012-04-20 13:05 ` [patch 10/18] mips: " Thomas Gleixner 2012-04-28 9:10 ` [tip:smp/hotplug] " tip-bot for Thomas Gleixner 2012-04-20 13:05 ` [patch 12/18] s390: " Thomas Gleixner 2012-04-23 7:09 ` Martin Schwidefsky 2012-04-28 9:11 ` [tip:smp/hotplug] " tip-bot for Thomas Gleixner 2012-04-20 13:05 ` [patch 13/18] blackfin: " Thomas Gleixner 2012-04-28 9:13 ` [tip:smp/hotplug] " tip-bot for Thomas Gleixner 2012-04-20 13:05 ` [patch 14/18] cris: " Thomas Gleixner 2012-04-23 7:57 ` Jesper Nilsson 2012-04-28 9:12 ` [tip:smp/hotplug] " tip-bot for Thomas Gleixner 2012-04-20 13:05 ` [patch 15/18] sh: " Thomas Gleixner 2012-04-21 3:18 ` Paul Mundt 2012-04-28 9:14 ` [tip:smp/hotplug] " tip-bot for Thomas Gleixner 2012-04-20 13:05 ` [patch 16/18] alpha: " Thomas Gleixner 2012-04-28 9:15 ` [tip:smp/hotplug] " tip-bot for Thomas Gleixner 2012-04-20 13:05 ` [patch 17/18] parisc: " Thomas Gleixner 2012-04-28 9:16 ` [tip:smp/hotplug] " tip-bot for Thomas Gleixner 2012-04-20 13:05 ` [patch 18/18] sparc: " Thomas Gleixner 2012-04-22 19:52 ` David Miller 2012-04-28 9:15 ` [tip:smp/hotplug] " tip-bot for Thomas Gleixner 2012-04-20 13:16 ` [patch 00/18] SMP: Boot and CPU hotplug refactoring - Part 1 Thomas Gleixner 2012-04-20 13:21 ` Peter Zijlstra 2012-04-20 13:47 ` Thomas Gleixner 2012-04-21 0:08 ` Suresh Siddha 2012-05-03 9:41 ` Thomas Gleixner 2012-05-03 23:42 ` Suresh Siddha 2012-05-03 17:43 ` [tip:smp/hotplug] smp, idle: Allocate idle thread for each possible cpu during boot tip-bot for Suresh Siddha 2012-04-20 15:42 ` [patch 00/18] SMP: Boot and CPU hotplug refactoring - Part 1 Tejun Heo 2012-04-20 15:49 ` Peter Zijlstra 2012-04-20 15:56 ` Thomas Gleixner 2012-04-20 13:56 ` Srivatsa S. Bhat 2012-04-20 14:18 ` Thomas Gleixner 2012-04-24 18:44 ` Konrad Rzeszutek Wilk 2012-05-21 1:42 ` Rusty Russell 2012-05-21 8:25 ` Thomas Gleixner 2012-05-22 0:53 ` Rusty Russell 2012-04-20 14:06 ` richard -rw- weinberger 2012-04-20 14:19 ` Thomas Gleixner 2012-04-20 14:27 ` James Bottomley 2012-04-20 17:55 ` Paul E. McKenney 2012-04-20 23:11 ` Venki Pallipadi 2012-04-21 1:04 ` Frank Rowand 2012-04-21 1:55 ` Frank Rowand 2012-04-22 21:01 ` Chris Metcalf 2012-04-22 21:01 ` Chris Metcalf 2012-04-22 21:01 ` Chris Metcalf 2012-04-30 8:05 ` Santosh Shilimkar
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