"[RFC - PATCH 0/7] consolidation of BUG support code."
https://lkml.org/lkml/2012/1/26/525
--
The changes shown here are to unify linux's BUG support under
the one <linux/bug.h> file. Due to historical reasons, we have
some BUG code in bug.h and some in kernel.h -- i.e. the support for
BUILD_BUG in linux/kernel.h predates the addition of linux/bug.h,
but old code in kernel.h wasn't moved to bug.h at that time. As
a band-aid, kernel.h was including <asm/bug.h> to pseudo link them.
This has caused confusion[1] and general yuck/WTF[2] reactions.
Here is an example that violates the principle of least surprise:
CC lib/string.o
lib/string.c: In function 'strlcat':
lib/string.c:225:2: error: implicit declaration of function 'BUILD_BUG_ON'
make[2]: *** [lib/string.o] Error 1
$
$ grep linux/bug.h lib/string.c
#include <linux/bug.h>
$
We've included <linux/bug.h> for the BUG infrastructure and yet we
still get a compile fail! [We've not kernel.h for BUILD_BUG_ON.]
Ugh - very confusing for someone who is new to kernel development.
With the above in mind, the goals of this changeset are:
1) find and fix any include/*.h files that were relying on the
implicit presence of BUG code.
2) find and fix any C files that were consuming kernel.h and
hence relying on implicitly getting some/all BUG code.
3) Move the BUG related code living in kernel.h to <linux/bug.h>
4) remove the asm/bug.h from kernel.h to finally break the chain.
During development, the order was more like 3-4, build-test, 1-2.
But to ensure that git history for bisect doesn't get needless
build failures introduced, the commits have been reorderd to fix
the problem areas in advance.
[1] https://lkml.org/lkml/2012/1/3/90
[2] https://lkml.org/lkml/2012/1/17/414
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Merge tag 'bug-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux
Pull <linux/bug.h> cleanup from Paul Gortmaker:
"The changes shown here are to unify linux's BUG support under the one
<linux/bug.h> file. Due to historical reasons, we have some BUG code
in bug.h and some in kernel.h -- i.e. the support for BUILD_BUG in
linux/kernel.h predates the addition of linux/bug.h, but old code in
kernel.h wasn't moved to bug.h at that time. As a band-aid, kernel.h
was including <asm/bug.h> to pseudo link them.
This has caused confusion[1] and general yuck/WTF[2] reactions. Here
is an example that violates the principle of least surprise:
CC lib/string.o
lib/string.c: In function 'strlcat':
lib/string.c:225:2: error: implicit declaration of function 'BUILD_BUG_ON'
make[2]: *** [lib/string.o] Error 1
$
$ grep linux/bug.h lib/string.c
#include <linux/bug.h>
$
We've included <linux/bug.h> for the BUG infrastructure and yet we
still get a compile fail! [We've not kernel.h for BUILD_BUG_ON.] Ugh -
very confusing for someone who is new to kernel development.
With the above in mind, the goals of this changeset are:
1) find and fix any include/*.h files that were relying on the
implicit presence of BUG code.
2) find and fix any C files that were consuming kernel.h and hence
relying on implicitly getting some/all BUG code.
3) Move the BUG related code living in kernel.h to <linux/bug.h>
4) remove the asm/bug.h from kernel.h to finally break the chain.
During development, the order was more like 3-4, build-test, 1-2. But
to ensure that git history for bisect doesn't get needless build
failures introduced, the commits have been reorderd to fix the problem
areas in advance.
[1] https://lkml.org/lkml/2012/1/3/90
[2] https://lkml.org/lkml/2012/1/17/414"
Fix up conflicts (new radeon file, reiserfs header cleanups) as per Paul
and linux-next.
* tag 'bug-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux:
kernel.h: doesn't explicitly use bug.h, so don't include it.
bug: consolidate BUILD_BUG_ON with other bug code
BUG: headers with BUG/BUG_ON etc. need linux/bug.h
bug.h: add include of it to various implicit C users
lib: fix implicit users of kernel.h for TAINT_WARN
spinlock: macroize assert_spin_locked to avoid bug.h dependency
x86: relocate get/set debugreg fcns to include/asm/debugreg.
Process accounting applications as top, ps visit some files under
/proc/<pid>. With seq_put_decimal_ull(), we can optimize /proc/<pid>/stat
and /proc/<pid>/statm files.
This patch adds
- seq_put_decimal_ll() for signed values.
- allow delimiter == 0.
- convert seq_printf() to seq_put_decimal_ull/ll in /proc/stat, statm.
Test result on a system with 2000+ procs.
Before patch:
[kamezawa@bluextal test]$ top -b -n 1 | wc -l
2223
[kamezawa@bluextal test]$ time top -b -n 1 > /dev/null
real 0m0.675s
user 0m0.044s
sys 0m0.121s
[kamezawa@bluextal test]$ time ps -elf > /dev/null
real 0m0.236s
user 0m0.056s
sys 0m0.176s
After patch:
kamezawa@bluextal ~]$ time top -b -n 1 > /dev/null
real 0m0.657s
user 0m0.052s
sys 0m0.100s
[kamezawa@bluextal ~]$ time ps -elf > /dev/null
real 0m0.198s
user 0m0.050s
sys 0m0.145s
Considering top, ps tend to scan /proc periodically, this will reduce cpu
consumption by top/ps to some extent.
[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
== stat_check.py
num = 0
with open("/proc/stat") as f:
while num < 1000 :
data = f.read()
f.seek(0, 0)
num = num + 1
==
perf shows
20.39% stat_check.py [kernel.kallsyms] [k] format_decode
13.41% stat_check.py [kernel.kallsyms] [k] number
12.61% stat_check.py [kernel.kallsyms] [k] vsnprintf
10.85% stat_check.py [kernel.kallsyms] [k] memcpy
4.85% stat_check.py [kernel.kallsyms] [k] radix_tree_lookup
4.43% stat_check.py [kernel.kallsyms] [k] seq_printf
This patch removes most of calls to vsnprintf() by adding num_to_str()
and seq_print_decimal_ull(), which prints decimal numbers without rich
functions provided by printf().
On my 8cpu box.
== Before patch ==
[root@bluextal test]# time ./stat_check.py
real 0m0.150s
user 0m0.026s
sys 0m0.121s
== After patch ==
[root@bluextal test]# time ./stat_check.py
real 0m0.055s
user 0m0.022s
sys 0m0.030s
[akpm@linux-foundation.org: remove incorrect comment, use less statck in num_to_str(), move comment from .h to .c, simplify seq_put_decimal_ull()]
[andrea@betterlinux.com: avoid breaking the ABI in /proc/stat]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrea Righi <andrea@betterlinux.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Glauber Costa <glommer@parallels.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Turner <pjt@google.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If a header file is making use of BUG, BUG_ON, BUILD_BUG_ON, or any
other BUG variant in a static inline (i.e. not in a #define) then
that header really should be including <linux/bug.h> and not just
expecting it to be implicitly present.
We can make this change risk-free, since if the files using these
headers didn't have exposure to linux/bug.h already, they would have
been causing compile failures/warnings.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Moving the event counter into the dynamically allocated 'struc seq_file'
allows poll() support without the need to allocate its own tracking
structure.
All current users are switched over to use the new counter.
Requested-by: Andrew Morton akpm@linux-foundation.org
Acked-by: NeilBrown <neilb@suse.de>
Tested-by: Lucas De Marchi lucas.demarchi@profusion.mobi
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Many usages of seq_file use RCU protected lists, so non RCU
iterators will not work safely.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Some places in kernel need to iterate over a hlist in seq_file,
so provide some common helpers.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add two helpers that allow access to the seq_file's own buffer, but
hide the internal details of seq_files.
This allows easier implementation of special purpose filling
functions. It also cleans up some existing functions which duplicated
the seq_file logic.
Make these inline functions in seq_file.h, as suggested by Al.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Acked-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
seq_write() can be used to construct seq_files containing arbitrary data.
Required by the gcov-profiling interface to synthesize binary profiling
data files.
Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Li Wei <W.Li@Sun.COM>
Cc: Michael Ellerman <michaele@au1.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Heiko Carstens <heicars2@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <mschwid2@linux.vnet.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently seq_read assumes that the offset passed to it is always the
offset it passed to user space. In the case pread this assumption is
broken and we do the wrong thing when presented with pread.
To solve this I introduce an offset cache inside of struct seq_file so we
know where our logical file position is. Then in seq_read if we try to
read from another offset we reset our data structures and attempt to go to
the offset user space wanted.
[akpm@linux-foundation.org: restore FMODE_PWRITE]
[pjt@google.com: seq_open needs its fmode opened up to take advantage of this]
Signed-off-by: Eric Biederman <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Paul Turner <pjt@google.com>
Cc: <stable@kernel.org> [2.6.25.x, 2.6.26.x, 2.6.27.x, 2.6.28.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Impact: cleanup, futureproof
nr_cpu_ids is the (badly named) runtime limit on possible CPU numbers;
ie. the variable version of NR_CPUS.
With the new cpumask operators, only bits less than this are defined.
So we should use it everywhere, rather than NR_CPUS. Eventually this
will make it possible to allocate cpumasks of the minimal length at runtime.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Mike Travis <travis@sgi.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup
seq_bitmap just calls bitmap_scnprintf on the bits: that arg can be const.
Similarly, seq_cpumask just calls seq_bitmap.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Impact: expose new VFS API
make mangle_path() available, as per the suggestions of Christoph Hellwig
and Al Viro:
http://lkml.org/lkml/2008/11/4/338
Signed-off-by: Török Edwin <edwintorok@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
seq_cpumask_list(), seq_nodemask_list() are very like seq_cpumask(),
seq_nodemask(), but they print human readable string.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Paul Menage <menage@google.com>
Cc: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Short enough reads from /proc/irq/*/smp_affinity return -EINVAL for no
good reason.
This became noticed with NR_CPUS=4096 patches, when length of printed
representation of cpumask becase 1152, but cat(1) continued to read with
1024-byte chunks. bitmap_scnprintf() in good faith fills buffer, returns
1023, check returns -EINVAL.
Fix it by switching to seq_file, so handler will just fill buffer and
doesn't care about offsets, length, filling EOF and all this crap.
For that add seq_bitmap(), and wrappers around it -- seq_cpumask() and
seq_nodemask().
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: Paul Jackson <pj@sgi.com>
Cc: Mike Travis <travis@sgi.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove the "#ifdef __KERNEL__" tests from unexported header files in
linux/include whose entire contents are wrapped in that preprocessor
test.
Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add a new function:
seq_file_root()
This is similar to seq_path(), but calculates the path relative to the
given root, instead of current->fs->root. If the path was unreachable
from root, then modify the root parameter to reflect this.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[mszeredi@suse.cz] split big patch into managable chunks
Add the following functions:
dentry_path()
seq_dentry()
These are similar to d_path() and seq_path(). But instead of
calculating the path within a mount namespace, they calculate the path
from the root of the filesystem to a given dentry, ignoring mounts
completely.
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This fix broken compilation for 'allnoconfig'. This was introduced by
Introduced by commit 1218854afa ("[NET]
NETNS: Omit seq_net_private->net without CONFIG_NET_NS.")
Signed-off-by: Denis V. Lunev <den@openvz.org>
Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Without CONFIG_NET_NS, no namespace other than &init_net exists,
no need to store net in seq_net_private.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
seq_path() is always called with a dentry and a vfsmount from a struct path.
Make seq_path() take it directly as an argument.
Signed-off-by: Jan Blunck <jblunck@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix f_version type: should be u64 instead of long
There is a type inconsistency between struct inode i_version and struct file
f_version.
fs.h:
struct inode
u64 i_version;
and
struct file
unsigned long f_version;
Users do:
fs/ext3/dir.c:
if (filp->f_version != inode->i_version) {
So why isn't f_version a u64 ? It becomes a problem if versions gets
higher than 2^32 and we are on an architecture where longs are 32 bits.
This patch changes the f_version type to u64, and updates the users accordingly.
It applies to 2.6.23-rc2-mm2.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Martin Bligh <mbligh@google.com>
Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: <linux-ext4@vger.kernel.org>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This function allocates the zeroed chunk of memory and
call seq_open(). The __seq_open_private() helper returns
the allocated memory to make it possible for the caller
to initialize it.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Many places in kernel use seq_file API to iterate over a regular list_head.
The code for such iteration is identical in all the places, so it's worth
introducing a common helpers.
This makes code about 300 lines smaller:
The first version of this patch made the helper functions static inline
in the seq_file.h header. This patch moves them to the fs/seq_file.c as
Andrew proposed. The vmlinux .text section sizes are as follows:
2.6.22-rc1-mm1: 0x001794d5
with the previous version: 0x00179505
with this patch: 0x00179135
The config file used was make allnoconfig with the "y" inclusion of all
the possible options to make the files modified by the patch compile plus
drivers I have on the test node.
This patch:
Many places in kernel use seq_file API to iterate over a regular list_head.
The code for such iteration is identical in all the places, so it's worth
introducing a common helpers.
Signed-off-by: Pavel Emelianov <xemul@openvz.org>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- move some file_operations structs into the .rodata section
- move static strings from policy_types[] array into the .rodata section
- fix generic seq_operations usages, so that those structs may be defined
as "const" as well
[akpm@osdl.org: couple of fixes]
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Semaphore to mutex conversion.
The conversion was generated via scripts, and the result was validated
automatically via a script as well.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Linus Torvalds