Re: [RFC PATCH] tinification: Introduce CONFIG_SRCU to make SRCU optional

From: Pranith Kumar
Date: Wed Dec 03 2014 - 21:21:47 EST

Next message: ethan zhao: "Re: [PATCH 2/2 V7] intel_pstate: add kernel parameter to force loading on Sun X86 servers."
Previous message: Greg Donald: "[PATCH] drivers: staging: rtl8723au: Fix "'foo * bar' should be 'foo *bar'" errors"
In reply to: Pranith Kumar: "[RFC PATCH] tinification: Introduce CONFIG_SRCU to make SRCU optional"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

On Wed, Dec 3, 2014 at 8:54 PM, Pranith Kumar <bobby.prani@xxxxxxxxx> wrote:
> (CC list restricted since this is just for initial feedback)
>
> SRCU is not necessary to be compiled by default in all cases. For tinification
> efforts not compiling SRCU unless necessary is desirable.
>
> The current patch tries to make compiling SRCU optional by introducing a new
> Kconfig option CONFIG_SRCU which is selected when any of the components making
> use of SRCU are selected.
>
> The current tinyconfig on x86 enables SRCU by default since x86 enables
> PERF_EVENTS which in-turn require SRCU support. If we disable PERF_EVENTS, we
> can disable compiling SRCU for tiny configs on x86 systems.
>
> I tested this using randconfig and building about 15 kernels. This is definitely
> not complete and could use more testing. Sticking it in next might help in that
> regards.
>
> Comments and suggestions are welcome. Please let me know if I should split
> up this patch.
>
> Signed-off-by: Pranith Kumar <bobby.prani@xxxxxxxxx>

So it looks like I missed a few places where this needs to be
set(cpufreq, devfreq, notifier etc.,)

I will update the patch and send it in.

Thanks!

> CC: Paul McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
> CC: Josh Triplett <josh@xxxxxxxxxxxxxxxx>
> ---
> arch/arm/kvm/Kconfig | 1 +
> arch/arm64/kvm/Kconfig | 1 +
> arch/ia64/kvm/Kconfig | 1 +
> arch/mips/kvm/Kconfig | 1 +
> arch/powerpc/kvm/Kconfig | 1 +
> arch/s390/kvm/Kconfig | 1 +
> arch/tile/kvm/Kconfig | 1 +
> arch/x86/kvm/Kconfig | 1 +
> drivers/md/Kconfig | 1 +
> drivers/net/Kconfig | 1 +
> fs/btrfs/Kconfig | 1 +
> fs/notify/Kconfig | 1 +
> init/Kconfig | 10 ++++++++++
> kernel/rcu/Makefile | 3 ++-
> lib/Kconfig.debug | 1 +
> mm/Kconfig | 1 +
> security/tomoyo/Kconfig | 1 +
> 17 files changed, 27 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm/kvm/Kconfig b/arch/arm/kvm/Kconfig
> index 466bd29..3afee5f 100644
> --- a/arch/arm/kvm/Kconfig
> +++ b/arch/arm/kvm/Kconfig
> @@ -23,6 +23,7 @@ config KVM
> select HAVE_KVM_CPU_RELAX_INTERCEPT
> select KVM_MMIO
> select KVM_ARM_HOST
> + select SRCU
> depends on ARM_VIRT_EXT && ARM_LPAE
> ---help---
> Support hosting virtualized guest machines. You will also
> diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig
> index 8ba85e9..b334084 100644
> --- a/arch/arm64/kvm/Kconfig
> +++ b/arch/arm64/kvm/Kconfig
> @@ -26,6 +26,7 @@ config KVM
> select KVM_ARM_HOST
> select KVM_ARM_VGIC
> select KVM_ARM_TIMER
> + select SRCU
> ---help---
> Support hosting virtualized guest machines.
>
> diff --git a/arch/ia64/kvm/Kconfig b/arch/ia64/kvm/Kconfig
> index 3d50ea9..f7d380b 100644
> --- a/arch/ia64/kvm/Kconfig
> +++ b/arch/ia64/kvm/Kconfig
> @@ -29,6 +29,7 @@ config KVM
> select HAVE_KVM_IRQ_ROUTING
> select KVM_APIC_ARCHITECTURE
> select KVM_MMIO
> + select SRCU
> ---help---
> Support hosting fully virtualized guest machines using hardware
> virtualization extensions. You will need a fairly recent
> diff --git a/arch/mips/kvm/Kconfig b/arch/mips/kvm/Kconfig
> index 30e334e..2ae1282 100644
> --- a/arch/mips/kvm/Kconfig
> +++ b/arch/mips/kvm/Kconfig
> @@ -20,6 +20,7 @@ config KVM
> select PREEMPT_NOTIFIERS
> select ANON_INODES
> select KVM_MMIO
> + select SRCU
> ---help---
> Support for hosting Guest kernels.
> Currently supported on MIPS32 processors.
> diff --git a/arch/powerpc/kvm/Kconfig b/arch/powerpc/kvm/Kconfig
> index 602eb51..af18e0f 100644
> --- a/arch/powerpc/kvm/Kconfig
> +++ b/arch/powerpc/kvm/Kconfig
> @@ -21,6 +21,7 @@ config KVM
> select PREEMPT_NOTIFIERS
> select ANON_INODES
> select HAVE_KVM_EVENTFD
> + select SRCU
>
> config KVM_BOOK3S_HANDLER
> bool
> diff --git a/arch/s390/kvm/Kconfig b/arch/s390/kvm/Kconfig
> index 646db9c..5fce52c 100644
> --- a/arch/s390/kvm/Kconfig
> +++ b/arch/s390/kvm/Kconfig
> @@ -28,6 +28,7 @@ config KVM
> select HAVE_KVM_IRQCHIP
> select HAVE_KVM_IRQFD
> select HAVE_KVM_IRQ_ROUTING
> + select SRCU
> ---help---
> Support hosting paravirtualized guest machines using the SIE
> virtualization capability on the mainframe. This should work
> diff --git a/arch/tile/kvm/Kconfig b/arch/tile/kvm/Kconfig
> index 2298cb1..1e968f7 100644
> --- a/arch/tile/kvm/Kconfig
> +++ b/arch/tile/kvm/Kconfig
> @@ -21,6 +21,7 @@ config KVM
> depends on HAVE_KVM && MODULES
> select PREEMPT_NOTIFIERS
> select ANON_INODES
> + select SRCU
> ---help---
> Support hosting paravirtualized guest machines.
>
> diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig
> index f9d16ff..7dc7ba5 100644
> --- a/arch/x86/kvm/Kconfig
> +++ b/arch/x86/kvm/Kconfig
> @@ -40,6 +40,7 @@ config KVM
> select HAVE_KVM_MSI
> select HAVE_KVM_CPU_RELAX_INTERCEPT
> select KVM_VFIO
> + select SRCU
> ---help---
> Support hosting fully virtualized guest machines using hardware
> virtualization extensions. You will need a fairly recent
> diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig
> index 5bdedf6..c355a22 100644
> --- a/drivers/md/Kconfig
> +++ b/drivers/md/Kconfig
> @@ -5,6 +5,7 @@
> menuconfig MD
> bool "Multiple devices driver support (RAID and LVM)"
> depends on BLOCK
> + select SRCU
> help
> Support multiple physical spindles through a single logical device.
> Required for RAID and logical volume management.
> diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
> index 4706386..221e623 100644
> --- a/drivers/net/Kconfig
> +++ b/drivers/net/Kconfig
> @@ -176,6 +176,7 @@ config NETCONSOLE_DYNAMIC
>
> config NETPOLL
> def_bool NETCONSOLE
> + select SRCU
>
> config NET_POLL_CONTROLLER
> def_bool NETPOLL
> diff --git a/fs/btrfs/Kconfig b/fs/btrfs/Kconfig
> index a66768e..80e9c18 100644
> --- a/fs/btrfs/Kconfig
> +++ b/fs/btrfs/Kconfig
> @@ -8,6 +8,7 @@ config BTRFS_FS
> select LZO_DECOMPRESS
> select RAID6_PQ
> select XOR_BLOCKS
> + select SRCU
>
> help
> Btrfs is a general purpose copy-on-write filesystem with extents,
> diff --git a/fs/notify/Kconfig b/fs/notify/Kconfig
> index 22c629e..2a24249 100644
> --- a/fs/notify/Kconfig
> +++ b/fs/notify/Kconfig
> @@ -1,5 +1,6 @@
> config FSNOTIFY
> def_bool n
> + select SRCU
>
> source "fs/notify/dnotify/Kconfig"
> source "fs/notify/inotify/Kconfig"
> diff --git a/init/Kconfig b/init/Kconfig
> index 3ee28ae..80ac0a4 100644
> --- a/init/Kconfig
> +++ b/init/Kconfig
> @@ -501,6 +501,14 @@ config TINY_RCU
>
> endchoice
>
> +config SRCU
> + bool "Sleepable form of RCU"
> + def_bool n
> + help
> + This option selects the sleepable version of RCU. This version
> + permits arbitrary sleeping or blocking within RCU read-side critical
> + sections.
> +
> config PREEMPT_RCU
> def_bool TREE_PREEMPT_RCU
> help
> @@ -510,6 +518,7 @@ config PREEMPT_RCU
> config TASKS_RCU
> bool "Task_based RCU implementation using voluntary context switch"
> default n
> + select SRCU
> help
> This option enables a task-based RCU implementation that uses
> only voluntary context switch (not preemption!), idle, and
> @@ -1586,6 +1595,7 @@ config PERF_EVENTS
> depends on HAVE_PERF_EVENTS
> select ANON_INODES
> select IRQ_WORK
> + select SRCU
> help
> Enable kernel support for various performance events provided
> by software and hardware.
> diff --git a/kernel/rcu/Makefile b/kernel/rcu/Makefile
> index 807ccfb..a484080 100644
> --- a/kernel/rcu/Makefile
> +++ b/kernel/rcu/Makefile
> @@ -1,4 +1,5 @@
> -obj-y += update.o srcu.o
> +obj-y += update.o
> +obj-$(CONFIG_SRCU) += srcu.o
> obj-$(CONFIG_RCU_TORTURE_TEST) += rcutorture.o
> obj-$(CONFIG_TREE_RCU) += tree.o
> obj-$(CONFIG_TREE_PREEMPT_RCU) += tree.o
> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
> index 4e35a5d..797511a 100644
> --- a/lib/Kconfig.debug
> +++ b/lib/Kconfig.debug
> @@ -1199,6 +1199,7 @@ config RCU_TORTURE_TEST
> tristate "torture tests for RCU"
> depends on DEBUG_KERNEL
> select TORTURE_TEST
> + select SRCU
> default n
> help
> This option provides a kernel module that runs torture tests
> diff --git a/mm/Kconfig b/mm/Kconfig
> index 1d1ae6b..4395b12 100644
> --- a/mm/Kconfig
> +++ b/mm/Kconfig
> @@ -325,6 +325,7 @@ config VIRT_TO_BUS
>
> config MMU_NOTIFIER
> bool
> + select SRCU
>
> config KSM
> bool "Enable KSM for page merging"
> diff --git a/security/tomoyo/Kconfig b/security/tomoyo/Kconfig
> index 8eb779b9d..604e718 100644
> --- a/security/tomoyo/Kconfig
> +++ b/security/tomoyo/Kconfig
> @@ -5,6 +5,7 @@ config SECURITY_TOMOYO
> select SECURITYFS
> select SECURITY_PATH
> select SECURITY_NETWORK
> + select SRCU
> default n
> help
> This selects TOMOYO Linux, pathname-based access control.
> --
> 1.9.1
>

--
Pranith
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

Next message: ethan zhao: "Re: [PATCH 2/2 V7] intel_pstate: add kernel parameter to force loading on Sun X86 servers."
Previous message: Greg Donald: "[PATCH] drivers: staging: rtl8723au: Fix "'foo * bar' should be 'foo *bar'" errors"
In reply to: Pranith Kumar: "[RFC PATCH] tinification: Introduce CONFIG_SRCU to make SRCU optional"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]