From: Tony Lindgren <tony@atomide.com> To: Russell King - ARM Linux <linux@arm.linux.org.uk> Cc: linux-arm-kernel@lists.infradead.org, linux-omap@vger.kernel.org, bryan.wu@canonical.com Subject: Re: [PATCH] ARM: Check for is_smp for tlb_ops and cache_ops boardcast Date: Wed, 6 Oct 2010 16:07:24 -0700 [thread overview] Message-ID: <20101006230724.GC4859@atomide.com> (raw) In-Reply-To: <20101006223358.GA7581@n2100.arm.linux.org.uk> * Russell King - ARM Linux <linux@arm.linux.org.uk> [101006 15:25]: > On Wed, Oct 06, 2010 at 07:44:14AM -0700, Tony Lindgren wrote: > > * Russell King - ARM Linux <linux@arm.linux.org.uk> [101005 15:24]: > > > On Tue, Oct 05, 2010 at 03:19:52PM -0700, Tony Lindgren wrote: > > > > * Tony Lindgren <tony@atomide.com> [100907 20:04]: > > > > > This should not be needed when running on UP systems. > > > > > > > > > > Additionally we will also get an undefined instruction on ARM cores > > > > > without the extended CPUID registers with CONFIG_SMP_ON_UP. > > > > > > > > > > Also, we can now remove the is_smp() test from mmu.c. > > > > > > > > Just FYI, I've updated this one more time with to use cpus_empty > > > > instead of !smp_on_up() here as well. > > > > > > What's the rationale? > > > > With CPU hotplug if the other SMP cores are unplugged for PM or > > other reasons, no need to do the broadcast. > > Yes, but why this expensive test when the smp_on_up() is much cheaper? > > smp_call_function_many() already takes care of the "no other CPUs" > case, which is used by on_each_cpu_mask() and on_each_cpu(), which > means these functions won't broadcast the operations to other CPUs > when they're offline. > > In any case, if you think that we broadcast every operation to all > CPUs, you're mistaken - TLB and cache ops are broadcast to only > those CPUs which the thread is running on, or in the case of non-MM > specific, to all online CPUs. OK thanks, that's what I was missing. > So the only thing we have to worry about is "is there an ID register > available" which is covered by the is_smp() test. Checking the CPU > mask is far more expensive and imho ends up needlessly adding to the > complexity. OK. In that case, the patch to use is the previous one: http://www.arm.linux.org.uk/developer/patches/viewpatch.php?id=6429/1 Regards, Tony
WARNING: multiple messages have this Message-ID (diff)
From: tony@atomide.com (Tony Lindgren) To: linux-arm-kernel@lists.infradead.org Subject: [PATCH] ARM: Check for is_smp for tlb_ops and cache_ops boardcast Date: Wed, 6 Oct 2010 16:07:24 -0700 [thread overview] Message-ID: <20101006230724.GC4859@atomide.com> (raw) In-Reply-To: <20101006223358.GA7581@n2100.arm.linux.org.uk> * Russell King - ARM Linux <linux@arm.linux.org.uk> [101006 15:25]: > On Wed, Oct 06, 2010 at 07:44:14AM -0700, Tony Lindgren wrote: > > * Russell King - ARM Linux <linux@arm.linux.org.uk> [101005 15:24]: > > > On Tue, Oct 05, 2010 at 03:19:52PM -0700, Tony Lindgren wrote: > > > > * Tony Lindgren <tony@atomide.com> [100907 20:04]: > > > > > This should not be needed when running on UP systems. > > > > > > > > > > Additionally we will also get an undefined instruction on ARM cores > > > > > without the extended CPUID registers with CONFIG_SMP_ON_UP. > > > > > > > > > > Also, we can now remove the is_smp() test from mmu.c. > > > > > > > > Just FYI, I've updated this one more time with to use cpus_empty > > > > instead of !smp_on_up() here as well. > > > > > > What's the rationale? > > > > With CPU hotplug if the other SMP cores are unplugged for PM or > > other reasons, no need to do the broadcast. > > Yes, but why this expensive test when the smp_on_up() is much cheaper? > > smp_call_function_many() already takes care of the "no other CPUs" > case, which is used by on_each_cpu_mask() and on_each_cpu(), which > means these functions won't broadcast the operations to other CPUs > when they're offline. > > In any case, if you think that we broadcast every operation to all > CPUs, you're mistaken - TLB and cache ops are broadcast to only > those CPUs which the thread is running on, or in the case of non-MM > specific, to all online CPUs. OK thanks, that's what I was missing. > So the only thing we have to worry about is "is there an ID register > available" which is covered by the is_smp() test. Checking the CPU > mask is far more expensive and imho ends up needlessly adding to the > complexity. OK. In that case, the patch to use is the previous one: http://www.arm.linux.org.uk/developer/patches/viewpatch.php?id=6429/1 Regards, Tony
next prev parent reply other threads:[~2010-10-06 23:07 UTC|newest] Thread overview: 230+ messages / expand[flat|nested] mbox.gz Atom feed top 2010-08-17 10:53 [PATCH 0/4] Hacks to allow booting ARM SMP kernel on UP ARMv7 Tony Lindgren 2010-08-17 10:53 ` Tony Lindgren 2010-08-17 10:53 ` [PATCH 1/4] ARM: Add SMP_ON_UP Kconfig option for booting SMP kernel on UP Tony Lindgren 2010-08-17 10:53 ` Tony Lindgren 2010-08-17 10:53 ` [PATCH 2/4] ARM: Allow optional UP processor functions for SMP kernels Tony Lindgren 2010-08-17 10:53 ` Tony Lindgren 2010-08-17 11:08 ` Russell King - ARM Linux 2010-08-17 11:08 ` Russell King - ARM Linux 2010-08-17 11:20 ` Tony Lindgren 2010-08-17 11:20 ` Tony Lindgren 2010-08-17 10:53 ` [PATCH 3/4] ARM: Set separate proc-v7 functions for SMP Tony Lindgren 2010-08-17 10:53 ` Tony Lindgren 2010-08-17 10:53 ` [PATCH 4/4] omap: Fix SMP on UP interrupt handling for multi-omap Tony Lindgren 2010-08-17 10:53 ` Tony Lindgren 2010-08-17 11:07 ` srinidhi 2010-08-17 11:07 ` srinidhi 2010-08-17 11:30 ` Tony Lindgren 2010-08-17 11:30 ` Tony Lindgren 2010-08-17 12:14 ` srinidhi 2010-08-17 12:14 ` srinidhi 2010-08-17 14:14 ` Tony Lindgren 2010-08-17 14:14 ` Tony Lindgren 2010-08-17 15:07 ` Shilimkar, Santosh 2010-08-17 15:07 ` Shilimkar, Santosh 2010-09-02 16:27 ` Tony Lindgren 2010-09-02 16:27 ` Tony Lindgren 2010-08-17 13:52 ` [PATCH 0/4] Hacks to allow booting ARM SMP kernel on UP ARMv7 Russell King - ARM Linux 2010-08-17 13:52 ` Russell King - ARM Linux 2010-08-17 14:12 ` Tony Lindgren 2010-08-17 14:12 ` Tony Lindgren 2010-08-17 15:40 ` Russell King - ARM Linux 2010-08-17 15:40 ` Russell King - ARM Linux 2010-08-19 7:38 ` Tony Lindgren 2010-08-19 7:38 ` Tony Lindgren 2010-08-19 9:38 ` Bryan Wu 2010-08-19 9:38 ` Bryan Wu 2010-08-19 9:57 ` Tony Lindgren 2010-08-19 9:57 ` Tony Lindgren 2010-08-19 10:20 ` Russell King - ARM Linux 2010-08-19 10:20 ` Russell King - ARM Linux 2010-08-20 12:06 ` Tony Lindgren 2010-08-20 12:06 ` Tony Lindgren 2010-08-30 22:55 ` Tony Lindgren 2010-08-30 22:55 ` Tony Lindgren 2010-09-02 13:36 ` Russell King - ARM Linux 2010-09-02 13:36 ` Russell King - ARM Linux 2010-09-02 16:16 ` Tony Lindgren 2010-09-02 16:16 ` Tony Lindgren 2010-09-02 16:18 ` [PATCH 1/6] ARM: Add inline function smp_on_up() for early init testing Tony Lindgren 2010-09-02 16:18 ` Tony Lindgren 2010-09-02 17:08 ` Russell King - ARM Linux 2010-09-02 17:08 ` Russell King - ARM Linux 2010-09-02 17:15 ` [PATCH 0/6] " Tony Lindgren 2010-09-02 17:15 ` Tony Lindgren 2010-09-02 17:42 ` [PATCH 1/6] " Tony Lindgren 2010-09-02 17:42 ` Tony Lindgren 2010-09-02 19:26 ` [PATCH 1/6] ARM: Add inline function smp_cpu() " Tony Lindgren 2010-09-02 19:26 ` Tony Lindgren 2010-09-03 0:08 ` Tony Lindgren 2010-09-03 0:08 ` Tony Lindgren 2010-09-03 2:22 ` Tony Lindgren 2010-09-03 2:22 ` Tony Lindgren 2010-09-03 8:58 ` Will Deacon 2010-09-03 9:02 ` Russell King - ARM Linux 2010-09-03 9:02 ` Russell King - ARM Linux 2010-09-03 9:07 ` Will Deacon 2010-09-03 9:07 ` Will Deacon 2010-09-03 8:58 ` Will Deacon 2010-09-03 12:12 ` Shilimkar, Santosh 2010-09-03 12:12 ` Shilimkar, Santosh 2010-09-03 12:23 ` Will Deacon 2010-09-03 12:23 ` Will Deacon 2010-09-03 12:31 ` Shilimkar, Santosh 2010-09-03 12:31 ` Shilimkar, Santosh 2010-09-05 1:53 ` Michał Nazarewicz 2010-09-05 1:53 ` Michał Nazarewicz 2010-09-03 12:09 ` [PATCH 1/6] ARM: Add inline function smp_on_up() " Shilimkar, Santosh 2010-09-03 12:09 ` Shilimkar, Santosh 2010-09-06 10:17 ` Bryan Wu 2010-09-06 10:17 ` Bryan Wu 2010-09-08 3:26 ` Tony Lindgren 2010-09-08 3:26 ` Tony Lindgren 2010-09-08 20:26 ` Tony Lindgren 2010-09-08 20:26 ` Tony Lindgren 2010-09-09 3:45 ` Bryan Wu 2010-09-09 3:45 ` Bryan Wu 2010-09-02 16:19 ` [PATCH 2/6] ARM: Use SMP and UP macros for cacheflush Tony Lindgren 2010-09-02 16:19 ` Tony Lindgren 2010-09-03 11:57 ` Shilimkar, Santosh 2010-09-03 11:57 ` Shilimkar, Santosh 2010-09-04 10:57 ` Russell King - ARM Linux 2010-09-04 10:57 ` Russell King - ARM Linux 2010-09-04 11:01 ` Shilimkar, Santosh 2010-09-04 11:01 ` Shilimkar, Santosh 2010-09-02 16:20 ` [PATCH 3/6] ARM: Fix v7wbi_tlb_flags for SMP on UP Tony Lindgren 2010-09-02 16:20 ` Tony Lindgren 2010-09-02 16:25 ` Russell King - ARM Linux 2010-09-02 16:25 ` Russell King - ARM Linux 2010-09-02 16:34 ` Tony Lindgren 2010-09-02 16:34 ` Tony Lindgren 2010-09-02 23:47 ` Tony Lindgren 2010-09-02 23:47 ` Tony Lindgren 2010-09-03 9:07 ` Russell King - ARM Linux 2010-09-03 9:07 ` Russell King - ARM Linux 2010-09-03 9:10 ` Russell King - ARM Linux 2010-09-03 9:10 ` Russell King - ARM Linux 2010-09-03 17:04 ` Tony Lindgren 2010-09-03 17:04 ` Tony Lindgren 2010-09-03 19:36 ` Russell King - ARM Linux 2010-09-03 19:36 ` Russell King - ARM Linux 2010-09-06 11:46 ` Catalin Marinas 2010-09-06 11:46 ` Catalin Marinas 2010-09-06 15:34 ` Russell King - ARM Linux 2010-09-06 15:34 ` Russell King - ARM Linux 2010-09-06 15:53 ` Catalin Marinas 2010-09-06 15:53 ` Catalin Marinas 2010-09-06 16:36 ` Russell King - ARM Linux 2010-09-06 16:36 ` Russell King - ARM Linux 2010-09-06 17:11 ` Catalin Marinas 2010-09-06 17:11 ` Catalin Marinas 2010-09-02 16:21 ` [PATCH 4/6] ARM: Do not call test_for_ipi or test_for_ltrirq on UP systems Tony Lindgren 2010-09-02 16:21 ` Tony Lindgren 2010-09-03 12:00 ` Shilimkar, Santosh 2010-09-03 12:00 ` Shilimkar, Santosh 2010-09-04 10:55 ` Russell King - ARM Linux 2010-09-04 10:55 ` Russell King - ARM Linux 2010-09-04 10:55 ` Russell King - ARM Linux 2010-09-04 10:55 ` Russell King - ARM Linux 2010-09-02 16:22 ` [PATCH 5/6] ARM: Don't set TLB ops broadcasting on UP ARMv7 Tony Lindgren 2010-09-02 16:22 ` Tony Lindgren 2010-09-02 16:57 ` Russell King - ARM Linux 2010-09-02 16:57 ` Russell King - ARM Linux 2010-09-02 17:21 ` Tony Lindgren 2010-09-02 17:21 ` Tony Lindgren 2010-09-02 18:01 ` Russell King - ARM Linux 2010-09-02 18:01 ` Russell King - ARM Linux 2010-09-02 18:13 ` Tony Lindgren 2010-09-02 18:13 ` Tony Lindgren 2010-09-02 18:18 ` Russell King - ARM Linux 2010-09-02 18:18 ` Russell King - ARM Linux 2010-09-02 16:23 ` [PATCH 6/6] omap: Fix SMP on UP interrupt handling for multi-omap Tony Lindgren 2010-09-02 16:23 ` Tony Lindgren 2010-09-02 19:30 ` Tony Lindgren 2010-09-02 19:30 ` Tony Lindgren 2010-09-03 12:15 ` Shilimkar, Santosh 2010-09-03 12:15 ` Shilimkar, Santosh 2010-09-08 3:30 ` Tony Lindgren 2010-09-08 3:30 ` Tony Lindgren 2010-09-03 12:06 ` Shilimkar, Santosh 2010-09-03 12:06 ` Shilimkar, Santosh 2010-09-04 11:05 ` Russell King - ARM Linux 2010-09-04 11:05 ` Russell King - ARM Linux 2010-09-04 11:22 ` Shilimkar, Santosh 2010-09-04 11:22 ` Shilimkar, Santosh 2010-09-03 4:20 ` [PATCH 0/4] Hacks to allow booting ARM SMP kernel on UP ARMv7 Bryan Wu 2010-09-03 4:20 ` Bryan Wu 2010-09-03 7:46 ` Russell King - ARM Linux 2010-09-03 7:46 ` Russell King - ARM Linux 2010-09-06 9:28 ` Catalin Marinas 2010-09-06 9:28 ` Catalin Marinas 2010-09-06 9:34 ` Russell King - ARM Linux 2010-09-06 9:34 ` Russell King - ARM Linux 2010-09-06 9:38 ` Catalin Marinas 2010-09-06 9:38 ` Catalin Marinas 2010-09-06 10:06 ` Russell King - ARM Linux 2010-09-06 10:06 ` Russell King - ARM Linux 2010-09-06 10:39 ` Catalin Marinas 2010-09-06 10:39 ` Catalin Marinas 2010-09-02 13:33 ` Russell King - ARM Linux 2010-09-02 13:33 ` Russell King - ARM Linux 2010-09-03 1:39 ` Tony Lindgren 2010-09-03 1:39 ` Tony Lindgren 2010-08-23 16:59 ` Will Deacon 2010-08-23 16:59 ` Will Deacon 2010-08-30 22:53 ` Tony Lindgren 2010-08-30 22:53 ` Tony Lindgren 2010-09-06 10:44 ` Russell King - ARM Linux 2010-09-06 10:44 ` Russell King - ARM Linux 2010-09-06 15:16 ` Catalin Marinas 2010-09-06 15:16 ` Catalin Marinas 2010-09-06 18:03 ` Tony Lindgren 2010-09-06 18:03 ` Tony Lindgren 2010-09-08 3:09 ` Tony Lindgren 2010-09-08 3:09 ` Tony Lindgren 2010-09-08 3:12 ` [PATCH] ARM: Check for is_smp for tlb_ops and cache_ops boardcast Tony Lindgren 2010-09-08 3:12 ` Tony Lindgren 2010-09-08 3:14 ` [PATCH] ARM: Don't try to send IPI on UP systems with CONFIG_SMP Tony Lindgren 2010-09-08 3:14 ` Tony Lindgren 2010-09-08 3:17 ` [PATCH] omap: Fix CONFIG_LOCAL_TIMERS initialization for multi-omap Tony Lindgren 2010-09-08 3:17 ` Tony Lindgren 2010-09-08 7:26 ` Shilimkar, Santosh 2010-09-08 7:26 ` Shilimkar, Santosh 2010-09-08 7:30 ` [PATCH] ARM: Don't try to send IPI on UP systems with CONFIG_SMP Shilimkar, Santosh 2010-09-08 7:30 ` Shilimkar, Santosh 2010-09-08 8:56 ` Russell King - ARM Linux 2010-09-08 8:56 ` Russell King - ARM Linux 2010-09-08 19:32 ` Tony Lindgren 2010-09-08 19:32 ` Tony Lindgren 2010-10-05 22:19 ` [PATCH] ARM: Check for is_smp for tlb_ops and cache_ops boardcast Tony Lindgren 2010-10-05 22:19 ` Tony Lindgren 2010-10-05 22:33 ` Russell King - ARM Linux 2010-10-05 22:33 ` Russell King - ARM Linux 2010-10-06 14:44 ` Tony Lindgren 2010-10-06 14:44 ` Tony Lindgren 2010-10-06 22:33 ` Russell King - ARM Linux 2010-10-06 22:33 ` Russell King - ARM Linux 2010-10-06 23:07 ` Tony Lindgren [this message] 2010-10-06 23:07 ` Tony Lindgren 2010-09-14 18:59 ` [PATCH] ARM: Handle __flush_icache_all for CONFIG_SMP_ON_UP Tony Lindgren 2010-09-14 18:59 ` Tony Lindgren 2010-09-14 19:03 ` [PATCH] omap: Update omap3_defconfig to work with SMP_ON_UP Tony Lindgren 2010-09-14 19:03 ` Tony Lindgren 2010-09-14 19:05 ` [PATCH] omap: Update omap3_defconfig for omap2 Tony Lindgren 2010-09-14 19:05 ` Tony Lindgren 2010-09-14 19:17 ` [PATCH] omap: Update omap3_defconfig to work with SMP_ON_UP Shilimkar, Santosh 2010-09-14 19:17 ` Shilimkar, Santosh 2010-09-14 20:27 ` Tony Lindgren 2010-09-14 20:27 ` Tony Lindgren 2010-09-15 6:11 ` Shilimkar, Santosh 2010-09-15 6:11 ` Shilimkar, Santosh 2010-09-15 16:11 ` Tony Lindgren 2010-09-15 16:11 ` Tony Lindgren 2010-09-15 18:25 ` Shilimkar, Santosh 2010-09-15 18:25 ` Shilimkar, Santosh 2010-09-15 23:15 ` Tony Lindgren 2010-09-15 23:15 ` Tony Lindgren 2010-09-16 17:05 ` [PATCH] ARM: Handle __flush_icache_all for CONFIG_SMP_ON_UP Catalin Marinas 2010-09-16 17:05 ` Catalin Marinas 2010-09-21 16:16 ` Tony Lindgren 2010-09-21 16:16 ` Tony Lindgren
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