From: Laurent Riffard <laurent.riffard@free.fr>
To: "Siddha, Suresh B" <suresh.b.siddha@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
linux-kernel@vger.kernel.org, Nick Piggin <npiggin@suse.de>
Subject: Re: 2.6.21-rc2-mm1: what about CONFIG_NO_HZ and !CONFIG_SMP ?
Date: Fri, 02 Mar 2007 23:09:58 +0100 [thread overview]
Message-ID: <45E8A0B6.4050900@free.fr> (raw)
In-Reply-To: <20070302125729.A27368@unix-os.sc.intel.com>
Le 02.03.2007 21:57, Siddha, Suresh B a écrit :
> On Fri, Mar 02, 2007 at 10:12:25PM +0100, Laurent Riffard wrote:
>> Le 02.03.2007 12:00, Andrew Morton a écrit :
>>> Temporarily at
>>>
>>> http://userweb.kernel.org/~akpm/2.6.21-rc2-mm1/
>>>
>>> Will appear later at
>>>
>>> ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.21-rc2/2.6.21-rc2-mm1/
>> Got this when CONFIG_NO_HZ=y and CONFIG_SMP=n:
>>
>> CC kernel/sched.o
>> kernel/sched.c: In function 'trigger_load_balance':
>> kernel/sched.c:3384: error: 'struct rq' has no member named 'in_nohz_recently'
>> kernel/sched.c:3384: error: 'struct rq' has no member named 'idle_at_tick'
>> kernel/sched.c:3385: error: 'struct rq' has no member named 'in_nohz_recently'
>> kernel/sched.c:3387: error: 'nohz' undeclared (first use in this function)
>> kernel/sched.c:3387: error: (Each undeclared identifier is reported only once
>> kernel/sched.c:3387: error: for each function it appears in.)
>> kernel/sched.c:3404: warning: implicit declaration of function 'resched_cpu'
>> kernel/sched.c:3412: error: 'struct rq' has no member named 'idle_at_tick'
>> kernel/sched.c:3422: error: 'struct rq' has no member named 'idle_at_tick'
>> make[1]: *** [kernel/sched.o] Error 1
>> make: *** [kernel] Error 2
>>
>> Looking at kernel/sched.c, it seems CONFIG_NO_HZ should depend on CONFIG_SMP...
>
> No. There is no such dependency. Can you please check if the below patch fixes
> the compilation issue. Thanks.
Yes, it does fix the compilation issue.
thanks
~~
laurent
> Move trigger_load_balance() under ifdef CONFIG_SMP.
>
> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
> ---
>
> diff -pNru linux-2.6.21-rc2/kernel/sched.c linux-mm/kernel/sched.c
> --- linux-2.6.21-rc2/kernel/sched.c 2007-03-02 13:23:46.000000000 -0800
> +++ linux-mm/kernel/sched.c 2007-03-02 13:26:38.000000000 -0800
> @@ -3156,6 +3156,68 @@ static void run_rebalance_domains(struct
> }
> #endif
> }
> +
> +/*
> + * Trigger the SCHED_SOFTIRQ if it is time to do periodic load balancing.
> + *
> + * In case of CONFIG_NO_HZ, this is the place where we nominate a new
> + * idle load balancing owner or decide to stop the periodic load balancing,
> + * if the whole system is idle.
> + */
> +static inline void trigger_load_balance(int cpu)
> +{
> + struct rq *rq = cpu_rq(cpu);
> +#ifdef CONFIG_NO_HZ
> + /*
> + * If we were in the nohz mode recently and busy at the current
> + * scheduler tick, then check if we need to nominate new idle
> + * load balancer.
> + */
> + if (rq->in_nohz_recently && !rq->idle_at_tick) {
> + rq->in_nohz_recently = 0;
> +
> + if (atomic_read(&nohz.load_balancer) == cpu) {
> + cpu_clear(cpu, nohz.cpu_mask);
> + atomic_set(&nohz.load_balancer, -1);
> + }
> +
> + if (atomic_read(&nohz.load_balancer) == -1) {
> + /*
> + * simple selection for now: Nominate the
> + * first cpu in the nohz list to be the next
> + * ilb owner.
> + *
> + * TBD: Traverse the sched domains and nominate
> + * the nearest cpu in the nohz.cpu_mask.
> + */
> + int ilb = first_cpu(nohz.cpu_mask);
> +
> + if (ilb != NR_CPUS)
> + resched_cpu(ilb);
> + }
> + }
> +
> + /*
> + * If this cpu is idle and doing idle load balancing for all the
> + * cpus with ticks stopped, is it time for that to stop?
> + */
> + if (rq->idle_at_tick && atomic_read(&nohz.load_balancer) == cpu &&
> + cpus_weight(nohz.cpu_mask) == num_online_cpus()) {
> + resched_cpu(cpu);
> + return;
> + }
> +
> + /*
> + * If this cpu is idle and the idle load balancing is done by
> + * someone else, then no need raise the SCHED_SOFTIRQ
> + */
> + if (rq->idle_at_tick && atomic_read(&nohz.load_balancer) != cpu &&
> + cpu_isset(cpu, nohz.cpu_mask))
> + return;
> +#endif
> + if (time_after_eq(jiffies, rq->next_balance))
> + raise_softirq(SCHED_SOFTIRQ);
> +}
> #else
> /*
> * on UP we do not need to balance between CPUs:
> @@ -3366,68 +3428,6 @@ out_unlock:
> }
>
> /*
> - * Trigger the SCHED_SOFTIRQ if it is time to do periodic load balancing.
> - *
> - * In case of CONFIG_NO_HZ, this is the place where we nominate a new
> - * idle load balancing owner or decide to stop the periodic load balancing,
> - * if the whole system is idle.
> - */
> -static inline void trigger_load_balance(int cpu)
> -{
> - struct rq *rq = cpu_rq(cpu);
> -#ifdef CONFIG_NO_HZ
> - /*
> - * If we were in the nohz mode recently and busy at the current
> - * scheduler tick, then check if we need to nominate new idle
> - * load balancer.
> - */
> - if (rq->in_nohz_recently && !rq->idle_at_tick) {
> - rq->in_nohz_recently = 0;
> -
> - if (atomic_read(&nohz.load_balancer) == cpu) {
> - cpu_clear(cpu, nohz.cpu_mask);
> - atomic_set(&nohz.load_balancer, -1);
> - }
> -
> - if (atomic_read(&nohz.load_balancer) == -1) {
> - /*
> - * simple selection for now: Nominate the
> - * first cpu in the nohz list to be the next
> - * ilb owner.
> - *
> - * TBD: Traverse the sched domains and nominate
> - * the nearest cpu in the nohz.cpu_mask.
> - */
> - int ilb = first_cpu(nohz.cpu_mask);
> -
> - if (ilb != NR_CPUS)
> - resched_cpu(ilb);
> - }
> - }
> -
> - /*
> - * If this cpu is idle and doing idle load balancing for all the
> - * cpus with ticks stopped, is it time for that to stop?
> - */
> - if (rq->idle_at_tick && atomic_read(&nohz.load_balancer) == cpu &&
> - cpus_weight(nohz.cpu_mask) == num_online_cpus()) {
> - resched_cpu(cpu);
> - return;
> - }
> -
> - /*
> - * If this cpu is idle and the idle load balancing is done by
> - * someone else, then no need raise the SCHED_SOFTIRQ
> - */
> - if (rq->idle_at_tick && atomic_read(&nohz.load_balancer) != cpu &&
> - cpu_isset(cpu, nohz.cpu_mask))
> - return;
> -#endif
> - if (time_after_eq(jiffies, rq->next_balance))
> - raise_softirq(SCHED_SOFTIRQ);
> -}
> -
> -/*
> * This function gets called by the timer code, with HZ frequency.
> * We call it with interrupts disabled.
> *
next prev parent reply other threads:[~2007-03-02 22:10 UTC|newest]
Thread overview: 129+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-03-02 11:00 2.6.21-rc2-mm1 Andrew Morton
2007-03-02 11:04 ` 2.6.21-rc2-mm1 Andrew Morton
2007-03-02 17:30 ` 2.6.21-rc2-mm1 Randy Dunlap
2007-03-04 11:58 ` [Re: 2.6.21-rc2-mm1] #error no ROMFS backing store interface configured Maciej Rutecki
2007-03-04 12:11 ` Andrew Morton
2007-03-04 15:11 ` Maciej Rutecki
2007-03-04 15:11 ` David Howells
2007-03-04 15:25 ` Adrian Bunk
2007-03-04 15:35 ` David Howells
2007-03-05 1:49 ` [-mm patch] fix the ROMFS_* dependencies Adrian Bunk
2007-03-05 13:36 ` David Howells
2007-03-06 23:43 ` Adrian Bunk
2007-03-02 11:04 ` 2.6.21-rc2-mm1 Russell King
2007-03-02 11:08 ` 2.6.21-rc2-mm1 Andrew Morton
2007-03-02 11:10 ` 2.6.21-rc2-mm1 Russell King
2007-03-02 11:15 ` 2.6.21-rc2-mm1 Andrew Morton
2007-03-03 18:03 ` 2.6.21-rc2-mm1 Russell King
2007-03-05 10:41 ` arm utrace Roland McGrath
2007-03-02 14:05 ` 2.6.21-rc2-mm1: EIP is at ext2_discard_reservation+0x1c/0x52 Alexey Dobriyan
2007-03-02 14:24 ` 2.6.21-rc2-mm1 Bryan Wu
2007-03-02 14:40 ` [-mm patch] cpu_idle: fix build break Frederik Deweerdt
2007-03-02 15:24 ` Venkatesh Pallipadi
2007-03-02 16:24 ` Frederik Deweerdt
2007-03-02 15:42 ` 2.6.21-rc2-mm1 - build error with HOTPLUG_CPU=N, CPU_IDLE=Y Valdis.Kletnieks
2007-03-02 15:56 ` 2.6.21-rc2-mm1 Michal Piotrowski
2007-03-05 10:14 ` 2.6.21-rc2-mm1 Andrew Morton
2007-03-05 10:30 ` 2.6.21-rc2-mm1 Antonino A. Daplas
2007-03-02 16:03 ` 2.6.21-rc2-mm1 - fb_ddc_read() not defined Valdis.Kletnieks
2007-03-02 16:31 ` James Simmons
2007-03-02 16:51 ` Valdis.Kletnieks
2007-03-02 16:19 ` [PATCH] longhaul pci_find_device -> pci_get_device conversion (was: Re: 2.6.21-rc2-mm1) Michal Piotrowski
[not found] ` <3888a5cd0703020945r4ca51f3dxe981050b817e7594@mail.gmail.com>
2007-03-02 18:10 ` Michal Piotrowski
2007-03-02 16:32 ` 2.6.21-rc2-mm1 Badari Pulavarty
2007-03-02 17:03 ` [patch -mm] x86_64: fake numa cmdline flag fix David Rientjes
2007-03-02 17:21 ` Badari Pulavarty
2007-03-02 17:10 ` 2.6.21-rc2-mm1 Andrew Morton
2007-03-02 17:15 ` 2.6.21-rc2-mm1 Badari Pulavarty
2007-03-02 21:12 ` 2.6.21-rc2-mm1: what about CONFIG_NO_HZ and !CONFIG_SMP ? Laurent Riffard
2007-03-02 20:57 ` Siddha, Suresh B
2007-03-02 22:09 ` Laurent Riffard [this message]
2007-03-02 22:52 ` 2.6.21-rc2-mm1: pata_via: wrong cable detection Laurent Riffard
2007-03-02 23:05 ` [PATCH -mm] char/epca.c remove unused function (was: Re: 2.6.21-rc2-mm1) Michal Piotrowski
2007-03-03 0:48 ` Alan Cox
2007-03-02 23:42 ` 2.6.21-rc2-mm1 Michal Piotrowski
2007-03-03 0:40 ` 2.6.21-rc2-mm1 Andrew Morton
2007-03-03 1:22 ` 2.6.21-rc2-mm1 Michal Piotrowski
2007-03-03 1:41 ` 2.6.21-rc2-mm1 Andrew Morton
2007-03-03 10:08 ` 2.6.21-rc2-mm1 Michal Piotrowski
2007-03-03 12:06 ` 2.6.21-rc2-mm1 Andrew Morton
2007-03-03 7:45 ` 2.6.21-rc2-mm1 - build error with CONFIG_NO_HZ=y and CONFIG_SMP=n Antonino A. Daplas
2007-03-03 7:59 ` Andrew Morton
2007-03-03 15:39 ` Keyboard stops working after *lock [Was: 2.6.21-rc2-mm1] Jiri Slaby
2007-03-03 15:54 ` Jiri Slaby
2007-03-03 17:41 ` Andrew Morton
2007-03-09 10:31 ` Jiri Slaby
2007-03-09 14:13 ` Dmitry Torokhov
2007-03-09 14:40 ` Jiri Kosina
2007-03-09 16:01 ` Jiri Kosina
2007-03-09 16:48 ` Jiri Slaby
2007-03-09 17:10 ` Jiri Slaby
2007-03-11 21:39 ` Jiri Slaby
2007-03-11 21:47 ` Jiri Kosina
2007-03-11 21:53 ` Jiri Slaby
2007-03-11 22:11 ` Jiri Slaby
2007-03-12 9:08 ` Jiri Slaby
2007-03-12 15:09 ` Alan Stern
2007-03-12 16:28 ` Jiri Slaby
2007-03-12 19:56 ` Alan Stern
2007-03-12 21:00 ` Jiri Kosina
2007-03-12 22:32 ` Jiri Slaby
2007-03-13 16:01 ` Alan Stern
2007-03-13 16:13 ` Jiri Slaby
2007-03-13 16:30 ` Alan Stern
2007-03-15 20:00 ` Alan Stern
2007-03-16 10:52 ` Jiri Slaby
2007-03-17 22:50 ` Jiri Slaby
2007-03-18 2:39 ` Alan Stern
2007-03-18 8:46 ` Jiri Slaby
2007-03-18 14:26 ` Alan Stern
2007-03-18 14:36 ` Jiri Slaby
2007-03-18 15:39 ` Alan Stern
2007-03-18 15:45 ` Jiri Slaby
2007-03-18 16:11 ` Alan Stern
2007-03-04 9:07 ` 2.6.21-rc2-mm1 Mariusz Kozlowski
2007-03-04 9:48 ` 2.6.21-rc2-mm1 Mariusz Kozlowski
2007-03-04 11:34 ` 2.6.21-rc2-mm1 Andrew Morton
2007-03-04 12:01 ` 2.6.21-rc2-mm1 Mariusz Kozlowski
2007-03-04 17:06 ` 2.6.21-rc2-mm1 Mariusz Kozlowski
2007-03-04 17:13 ` 2.6.21-rc2-mm1 Michal Piotrowski
2007-03-04 17:20 ` 2.6.21-rc2-mm1 Michal Piotrowski
2007-03-05 16:34 ` 2.6.21-rc2-mm1 Zan Lynx
2007-03-05 0:11 ` 2.6.21-rc2-mm1 J.A. Magallón
2007-03-05 0:29 ` 2.6.21-rc2-mm1 Andrew Morton
2007-03-05 1:17 ` 2.6.21-rc2-mm1 Andrew Morton
2007-03-05 2:25 ` 2.6.21-rc2-mm1 Neil Brown
2007-03-05 15:42 ` 2.6.21-rc2-mm1 Bill Davidsen
2007-03-05 1:47 ` [-mm patch] saa7134: fix MODULES=n compilation Adrian Bunk
2007-03-05 1:47 ` 2.6.21-rc2-mm1: drivers/net/wireless/ compile error Adrian Bunk
2007-03-05 10:41 ` Michael Buesch
2007-03-05 1:47 ` 2.6.21-rc2-mm1: drivers/usb/host/ohci-ssb.c doesn't compile Adrian Bunk
2007-03-05 10:49 ` Michael Buesch
2007-03-05 10:57 ` Michael Buesch
2007-03-05 11:26 ` Michael Buesch
2007-03-05 18:26 ` Greg KH
2007-03-05 18:37 ` Adrian Bunk
2007-03-05 18:42 ` David Brownell
2007-03-05 19:09 ` Michael Buesch
2007-03-05 1:47 ` [-mm patch] arch/i386/kernel/vmi.c must #include <asm/kmap_types.h> Adrian Bunk
2007-03-05 2:57 ` Zachary Amsden
2007-03-05 1:47 ` [-mm patch] remove arch/i386/kernel/tsc.c:custom_sched_clock Adrian Bunk
2007-03-05 2:57 ` Zachary Amsden
2007-03-05 1:47 ` [-mm patch] make drivers/char/drm/drm_vm.c:drm_io_prot() static Adrian Bunk
2007-03-05 1:47 ` [-mm patch] drivers/cpuidle/: make code static Adrian Bunk
2007-03-05 1:49 ` [-mm patch] drivers/media/video/ivtv/: possible cleanups Adrian Bunk
2007-03-05 6:53 ` [v4l-dvb-maintainer] " Hans Verkuil
2007-03-05 1:49 ` [-mm patch] drivers/net/bonding/bond_main.c:make 3 functions static Adrian Bunk
2007-03-05 1:49 ` [-mm patch] make drivers/video/display/display-sysfs.c:display_class static Adrian Bunk
2007-03-05 1:49 ` [-mm patch] make fb_deferred_io_mkwrite() static Adrian Bunk
2007-03-05 1:49 ` [-mm patch] drivers/video/hecubafb.c: make 4 functions static Adrian Bunk
2007-03-05 22:20 ` 2.6.21-rc2-mm1 J.A. Magallón
2007-03-05 23:11 ` 2.6.21-rc2-mm1 Andrew Morton
2007-03-06 6:25 ` [PATCH] sched: fix idle at tick Con Kolivas
[not found] ` <20070305230240.9c2741d1.akpm@linux-foundation.org>
2007-03-06 7:41 ` Con Kolivas
2007-03-06 8:38 ` J.A. Magallón
2007-03-06 0:16 ` i2c vs nVidia [Re: 2.6.21-rc2-mm1] J.A. Magallón
2007-03-06 0:33 ` Andrew Morton
2007-03-06 0:44 ` Greg KH
2007-03-06 8:45 ` Jean Delvare
2007-03-06 10:56 ` Jean Delvare
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