From: Aristeu Rozanski <[email protected]>
flex_array currently is built unconditionally:
text data bss dec hex filename
2294 1008 1568 4870 1306 lib/flex_array.o
2294 1008 1568 4870 1306 (TOTALS)
and it's used by procfs, selinux and openvswitch. This patch is
useful for situations in which memory footprint is a concern and
those features aren't used.
Cc: Changli Gao <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Eric Paris <[email protected]>
Cc: Hannes Frederic Sowa <[email protected]>
Cc: Jesse Gross <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Paul Gortmaker <[email protected]>
Cc: Pravin Shelar <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Josh Triplett <[email protected]>
Signed-off-by: Aristeu Rozanski <[email protected]>
---
fs/proc/Kconfig | 1 +
lib/Kconfig | 10 ++++++++++
lib/Makefile | 3 ++-
net/openvswitch/Kconfig | 1 +
security/selinux/Kconfig | 1 +
5 files changed, 15 insertions(+), 1 deletion(-)
diff --git a/fs/proc/Kconfig b/fs/proc/Kconfig
index 2183fcf..2d624b7 100644
--- a/fs/proc/Kconfig
+++ b/fs/proc/Kconfig
@@ -1,6 +1,7 @@
config PROC_FS
bool "/proc file system support" if EXPERT
default y
+ select FLEX_ARRAY
help
This is a virtual file system providing information about the status
of the system. "Virtual" means that it doesn't take up any space on
diff --git a/lib/Kconfig b/lib/Kconfig
index 54cf309..675920b 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -432,6 +432,16 @@ config GLOB_SELFTEST
module load) by a small amount, so you're welcome to play with
it, but you probably don't need it.
+config FLEX_ARRAY
+ bool "Flexible array"
+ default n
+ help
+ This option enables an implementation of flexible arrays which
+ allows creating arrays of fixed size elements with an arbritrary
+ size without requiring the single allocation of a contiguous area.
+
+ See Documentation/flexible-arrays.txt
+
#
# Netlink attribute parsing support is select'ed if needed
#
diff --git a/lib/Makefile b/lib/Makefile
index 7512dc9..9c12cbc 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -24,7 +24,7 @@ obj-y += lockref.o
obj-y += bcd.o div64.o sort.o parser.o halfmd4.o debug_locks.o random32.o \
bust_spinlocks.o hexdump.o kasprintf.o bitmap.o scatterlist.o \
- gcd.o lcm.o list_sort.o uuid.o flex_array.o iovec.o clz_ctz.o \
+ gcd.o lcm.o list_sort.o uuid.o iovec.o clz_ctz.o \
bsearch.o find_last_bit.o find_next_bit.o llist.o memweight.o kfifo.o \
percpu-refcount.o percpu_ida.o hash.o rhashtable.o
obj-y += string_helpers.o
@@ -35,6 +35,7 @@ obj-$(CONFIG_TEST_LKM) += test_module.o
obj-$(CONFIG_TEST_USER_COPY) += test_user_copy.o
obj-$(CONFIG_TEST_BPF) += test_bpf.o
obj-$(CONFIG_TEST_FIRMWARE) += test_firmware.o
+obj-$(CONFIG_FLEX_ARRAY) += flex_array.o
ifeq ($(CONFIG_DEBUG_KOBJECT),y)
CFLAGS_kobject.o += -DDEBUG
diff --git a/net/openvswitch/Kconfig b/net/openvswitch/Kconfig
index ba3bb82..1d979ce 100644
--- a/net/openvswitch/Kconfig
+++ b/net/openvswitch/Kconfig
@@ -5,6 +5,7 @@
config OPENVSWITCH
tristate "Open vSwitch"
select LIBCRC32C
+ select FLEX_ARRAY
---help---
Open vSwitch is a multilayer Ethernet switch targeted at virtualized
environments. In addition to supporting a variety of features
diff --git a/security/selinux/Kconfig b/security/selinux/Kconfig
index bca1b74..cfcc7c1 100644
--- a/security/selinux/Kconfig
+++ b/security/selinux/Kconfig
@@ -2,6 +2,7 @@ config SECURITY_SELINUX
bool "NSA SELinux Support"
depends on SECURITY_NETWORK && AUDIT && NET && INET
select NETWORK_SECMARK
+ select FLEX_ARRAY
default n
help
This selects NSA Security-Enhanced Linux (SELinux).
--
1.8.3.1
On 11/06/2014 01:27 PM, Aristeu Rozanski wrote:
> +config FLEX_ARRAY
> + bool "Flexible array"
> + default n
> + help
> + This option enables an implementation of flexible arrays which
> + allows creating arrays of fixed size elements with an arbritrary
> + size without requiring the single allocation of a contiguous area.
> +
> + See Documentation/flexible-arrays.txt
Is there any reason to expose this to the user via Kconfig?
No sane person would even turn it on if they don't need it.
On 11/06/2014 01:33 PM, Dave Hansen wrote:
> On 11/06/2014 01:27 PM, Aristeu Rozanski wrote:
>> +config FLEX_ARRAY
>> + bool "Flexible array"
>> + default n
>> + help
>> + This option enables an implementation of flexible arrays which
>> + allows creating arrays of fixed size elements with an arbritrary
>> + size without requiring the single allocation of a contiguous area.
>> +
>> + See Documentation/flexible-arrays.txt
>
> Is there any reason to expose this to the user via Kconfig?
>
> No sane person would even turn it on if they don't need it.
IOW, I think you should just make it:
config FLEX_ARRAY
def_bool n
On Thu, Nov 06, 2014 at 04:27:21PM -0500, Aristeu Rozanski wrote:
> From: Aristeu Rozanski <[email protected]>
>
> flex_array currently is built unconditionally:
> text data bss dec hex filename
> 2294 1008 1568 4870 1306 lib/flex_array.o
> 2294 1008 1568 4870 1306 (TOTALS)
>
> and it's used by procfs, selinux and openvswitch. This patch is
> useful for situations in which memory footprint is a concern and
> those features aren't used.
>
> Cc: Changli Gao <[email protected]>
> Cc: Dave Hansen <[email protected]>
> Cc: David Rientjes <[email protected]>
> Cc: Eric Paris <[email protected]>
> Cc: Hannes Frederic Sowa <[email protected]>
> Cc: Jesse Gross <[email protected]>
> Cc: Jonathan Corbet <[email protected]>
> Cc: Paul Gortmaker <[email protected]>
> Cc: Pravin Shelar <[email protected]>
> Cc: Alexander Viro <[email protected]>
> Cc: Josh Triplett <[email protected]>
> Signed-off-by: Aristeu Rozanski <[email protected]>
I already have a patch for this sitting in the tiny tree (branch
tiny/unflex-array) for the next merge window, and that patch hides the
symbol from the user, just selecting it internally.
I've updated the tinification project list to mark that and several
other projects as "done" or "in progress".
- Josh Triplett
> fs/proc/Kconfig | 1 +
> lib/Kconfig | 10 ++++++++++
> lib/Makefile | 3 ++-
> net/openvswitch/Kconfig | 1 +
> security/selinux/Kconfig | 1 +
> 5 files changed, 15 insertions(+), 1 deletion(-)
>
> diff --git a/fs/proc/Kconfig b/fs/proc/Kconfig
> index 2183fcf..2d624b7 100644
> --- a/fs/proc/Kconfig
> +++ b/fs/proc/Kconfig
> @@ -1,6 +1,7 @@
> config PROC_FS
> bool "/proc file system support" if EXPERT
> default y
> + select FLEX_ARRAY
> help
> This is a virtual file system providing information about the status
> of the system. "Virtual" means that it doesn't take up any space on
> diff --git a/lib/Kconfig b/lib/Kconfig
> index 54cf309..675920b 100644
> --- a/lib/Kconfig
> +++ b/lib/Kconfig
> @@ -432,6 +432,16 @@ config GLOB_SELFTEST
> module load) by a small amount, so you're welcome to play with
> it, but you probably don't need it.
>
> +config FLEX_ARRAY
> + bool "Flexible array"
> + default n
> + help
> + This option enables an implementation of flexible arrays which
> + allows creating arrays of fixed size elements with an arbritrary
> + size without requiring the single allocation of a contiguous area.
> +
> + See Documentation/flexible-arrays.txt
> +
> #
> # Netlink attribute parsing support is select'ed if needed
> #
> diff --git a/lib/Makefile b/lib/Makefile
> index 7512dc9..9c12cbc 100644
> --- a/lib/Makefile
> +++ b/lib/Makefile
> @@ -24,7 +24,7 @@ obj-y += lockref.o
>
> obj-y += bcd.o div64.o sort.o parser.o halfmd4.o debug_locks.o random32.o \
> bust_spinlocks.o hexdump.o kasprintf.o bitmap.o scatterlist.o \
> - gcd.o lcm.o list_sort.o uuid.o flex_array.o iovec.o clz_ctz.o \
> + gcd.o lcm.o list_sort.o uuid.o iovec.o clz_ctz.o \
> bsearch.o find_last_bit.o find_next_bit.o llist.o memweight.o kfifo.o \
> percpu-refcount.o percpu_ida.o hash.o rhashtable.o
> obj-y += string_helpers.o
> @@ -35,6 +35,7 @@ obj-$(CONFIG_TEST_LKM) += test_module.o
> obj-$(CONFIG_TEST_USER_COPY) += test_user_copy.o
> obj-$(CONFIG_TEST_BPF) += test_bpf.o
> obj-$(CONFIG_TEST_FIRMWARE) += test_firmware.o
> +obj-$(CONFIG_FLEX_ARRAY) += flex_array.o
>
> ifeq ($(CONFIG_DEBUG_KOBJECT),y)
> CFLAGS_kobject.o += -DDEBUG
> diff --git a/net/openvswitch/Kconfig b/net/openvswitch/Kconfig
> index ba3bb82..1d979ce 100644
> --- a/net/openvswitch/Kconfig
> +++ b/net/openvswitch/Kconfig
> @@ -5,6 +5,7 @@
> config OPENVSWITCH
> tristate "Open vSwitch"
> select LIBCRC32C
> + select FLEX_ARRAY
> ---help---
> Open vSwitch is a multilayer Ethernet switch targeted at virtualized
> environments. In addition to supporting a variety of features
> diff --git a/security/selinux/Kconfig b/security/selinux/Kconfig
> index bca1b74..cfcc7c1 100644
> --- a/security/selinux/Kconfig
> +++ b/security/selinux/Kconfig
> @@ -2,6 +2,7 @@ config SECURITY_SELINUX
> bool "NSA SELinux Support"
> depends on SECURITY_NETWORK && AUDIT && NET && INET
> select NETWORK_SECMARK
> + select FLEX_ARRAY
> default n
> help
> This selects NSA Security-Enhanced Linux (SELinux).
> --
> 1.8.3.1
>
On Thu, Nov 06, 2014 at 01:44:54PM -0800, Dave Hansen wrote:
> On 11/06/2014 01:33 PM, Dave Hansen wrote:
> > On 11/06/2014 01:27 PM, Aristeu Rozanski wrote:
> >> +config FLEX_ARRAY
> >> + bool "Flexible array"
> >> + default n
> >> + help
> >> + This option enables an implementation of flexible arrays which
> >> + allows creating arrays of fixed size elements with an arbritrary
> >> + size without requiring the single allocation of a contiguous area.
> >> +
> >> + See Documentation/flexible-arrays.txt
> >
> > Is there any reason to expose this to the user via Kconfig?
> >
> > No sane person would even turn it on if they don't need it.
>
> IOW, I think you should just make it:
>
> config FLEX_ARRAY
> def_bool n
Joe Pershes complained on a similar patch on making it default to 'n'.
Will rework the patches this way.
--
Aristeu
On Thu, Nov 06, 2014 at 04:50:56PM -0500, Aristeu Rozanski wrote:
> On Thu, Nov 06, 2014 at 01:44:54PM -0800, Dave Hansen wrote:
> > On 11/06/2014 01:33 PM, Dave Hansen wrote:
> > > On 11/06/2014 01:27 PM, Aristeu Rozanski wrote:
> > >> +config FLEX_ARRAY
> > >> + bool "Flexible array"
> > >> + default n
> > >> + help
> > >> + This option enables an implementation of flexible arrays which
> > >> + allows creating arrays of fixed size elements with an arbritrary
> > >> + size without requiring the single allocation of a contiguous area.
> > >> +
> > >> + See Documentation/flexible-arrays.txt
> > >
> > > Is there any reason to expose this to the user via Kconfig?
> > >
> > > No sane person would even turn it on if they don't need it.
> >
> > IOW, I think you should just make it:
> >
> > config FLEX_ARRAY
> > def_bool n
>
> Joe Pershes complained on a similar patch on making it default to 'n'.
> Will rework the patches this way.
https://git.kernel.org/cgit/linux/kernel/git/josh/linux.git/commit/?h=tiny/unflex-array&id=6631d5fb4cf395ebd2dc0f2da05525b9d3436a3f
Already done.
- Josh Triplett
On Thu, 6 Nov 2014, Josh Triplett wrote:
> https://git.kernel.org/cgit/linux/kernel/git/josh/linux.git/commit/?h=tiny/unflex-array&id=6631d5fb4cf395ebd2dc0f2da05525b9d3436a3f
>
> Already done.
>
Thanks Josh, and the "unflex array" patch title is great.
Acked-by: David Rientjes <[email protected]>