20 Jul, 2007
40 commits
-
Transform some calls to kmalloc/memset to a single kzalloc (or kcalloc).
Here is a short excerpt of the semantic patch performing
this transformation:@@
type T2;
expression x;
identifier f,fld;
expression E;
expression E1,E2;
expression e1,e2,e3,y;
statement S;
@@x =
- kmalloc
+ kzalloc
(E1,E2)
... when != \(x->fld=E;\|y=f(...,x,...);\|f(...,x,...);\|x=E;\|while(...) S\|for(e1;e2;e3) S\)
- memset((T2)x,0,E1);@@
expression E1,E2,E3;
@@- kzalloc(E1 * E2,E3)
+ kcalloc(E1,E2,E3)[akpm@linux-foundation.org: get kcalloc args the right way around]
Signed-off-by: Yoann Padioleau
Cc: Richard Henderson
Cc: Ivan Kokshaysky
Acked-by: Russell King
Cc: Bryan Wu
Acked-by: Jiri Slaby
Cc: Dave Airlie
Acked-by: Roland Dreier
Cc: Jiri Kosina
Acked-by: Dmitry Torokhov
Cc: Benjamin Herrenschmidt
Acked-by: Mauro Carvalho Chehab
Acked-by: Pierre Ossman
Cc: Jeff Garzik
Cc: "David S. Miller"
Acked-by: Greg KH
Cc: James Bottomley
Cc: "Antonino A. Daplas"
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The print_stack_trace macro in stacktrace.h has a wrong number of
arguments, fix it.Signed-off-by: Johannes Berg
Cc: Ingo Molnar
Cc: Peter Zijlstra
Cc: Arjan van de Ven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
When I started adding support for lockdep to 64-bit powerpc, I got a
lockdep_init_error and with this patch was able to pinpoint why and where
to put lockdep_init(). Let's support this generally for others adding
lockdep support to their architecture.Signed-off-by: Johannes Berg
Cc: Ingo Molnar
Cc: Peter Zijlstra
Cc: Arjan van de Ven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
optionally add class->name_version and class->subclass to the class name
Signed-off-by: Peter Zijlstra
Cc: Ingo Molnar
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
__acquire
|
lock _____
| \
| __contended
| |
| wait
| _______/
|/
|
__acquired
|
__release
|
unlockWe measure acquisition and contention bouncing.
This is done by recording a cpu stamp in each lock instance.
Contention bouncing requires the cpu stamp to be set on acquisition. Hence we
move __acquired into the generic path.__acquired is then used to measure acquisition bouncing by comparing the
current cpu with the old stamp before replacing it.__contended is used to measure contention bouncing (only useful for preemptable
locks)[akpm@linux-foundation.org: cleanups]
Signed-off-by: Peter Zijlstra
Acked-by: Ingo Molnar
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
the two init sites resulted in inconsistend names for the lock class.
Signed-off-by: Peter Zijlstra
Acked-by: Ingo Molnar
Cc: "David S. Miller"
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
- update the copyright notices
- use the default hash function
- fix a thinko in a BUILD_BUG_ON
- add a WARN_ON to spot inconsitent naming
- fix a termination issue in /proc/lock_stat[akpm@linux-foundation.org: cleanups]
Signed-off-by: Peter Zijlstra
Acked-by: Ingo Molnar
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Call the new lockstat tracking functions from the various lock primitives.
Signed-off-by: Peter Zijlstra
Acked-by: Ingo Molnar
Acked-by: Jason Baron
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Present all this fancy new lock statistics information:
*warning, _wide_ output ahead*
(output edited for purpose of brevity)
# cat /proc/lock_stat
lock_stat version 0.1
-----------------------------------------------------------------------------------------------------------------------------------------------------------------
class name contentions waittime-min waittime-max waittime-total acquisitions holdtime-min holdtime-max holdtime-total
-----------------------------------------------------------------------------------------------------------------------------------------------------------------&inode->i_mutex: 14458 6.57 398832.75 2469412.23 6768876 0.34 11398383.65 339410830.89
---------------
&inode->i_mutex 4486 [] pipe_wait+0x86/0x8d
&inode->i_mutex 0 [] pipe_write_fasync+0x29/0x5d
&inode->i_mutex 0 [] pipe_read+0x74/0x3a5
&inode->i_mutex 0 [] do_lookup+0x81/0x1ae.................................................................................................................................................................
&inode->i_data.tree_lock-W: 491 0.27 62.47 493.89 2477833 0.39 468.89 1146584.25
&inode->i_data.tree_lock-R: 65 0.44 4.27 48.78 26288792 0.36 184.62 10197458.24
--------------------------
&inode->i_data.tree_lock 46 [] __do_page_cache_readahead+0x69/0x24f
&inode->i_data.tree_lock 31 [] add_to_page_cache+0x31/0xba
&inode->i_data.tree_lock 0 [] __do_page_cache_readahead+0xc2/0x24f
&inode->i_data.tree_lock 0 [] find_get_page+0x1a/0x58.................................................................................................................................................................
proc_inum_idr.lock: 0 0.00 0.00 0.00 36 0.00 65.60 148.26
proc_subdir_lock: 0 0.00 0.00 0.00 3049859 0.00 106.81 1563212.42
shrinker_rwsem-W: 0 0.00 0.00 0.00 5 0.00 1.73 3.68
shrinker_rwsem-R: 0 0.00 0.00 0.00 633 2.57 246.57 10909.76'contentions' and 'acquisitions' are the number of such events measured (since
the last reset). The waittime- and holdtime- (min, max, total) numbers are
presented in microseconds.If there are any contention points, the lock class is presented in the block
format (as i_mutex and tree_lock above), otherwise a single line of output is
presented.The output is sorted on absolute number of contentions (read + write), this
should get the worst offenders presented first, so that:# grep : /proc/lock_stat | head
will quickly show who's bad.
The stats can be reset using:
# echo 0 > /proc/lock_stat
[bunk@stusta.de: make 2 functions static]
[akpm@linux-foundation.org: fix printk warning]
Signed-off-by: Peter Zijlstra
Acked-by: Ingo Molnar
Acked-by: Jason Baron
Signed-off-by: Adrian Bunk
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Introduce the core lock statistics code.
Lock statistics provides lock wait-time and hold-time (as well as the count
of corresponding contention and acquisitions events). Also, the first few
call-sites that encounter contention are tracked.Lock wait-time is the time spent waiting on the lock. This provides insight
into the locking scheme, that is, a heavily contended lock is indicative of
a too coarse locking scheme.Lock hold-time is the duration the lock was held, this provides a reference for
the wait-time numbers, so they can be put into perspective.1)
lock
2)
... do stuff ..
unlock
3)The time between 1 and 2 is the wait-time. The time between 2 and 3 is the
hold-time.The lockdep held-lock tracking code is reused, because it already collects locks
into meaningful groups (classes), and because it is an existing infrastructure
for lock instrumentation.Currently lockdep tracks lock acquisition with two hooks:
lock()
lock_acquire()
_lock()... code protected by lock ...
unlock()
lock_release()
_unlock()We need to extend this with two more hooks, in order to measure contention.
lock_contended() - used to measure contention events
lock_acquired() - completion of the contentionThese are then placed the following way:
lock()
lock_acquire()
if (!_try_lock())
lock_contended()
_lock()
lock_acquired()... do locked stuff ...
unlock()
lock_release()
_unlock()(Note: the try_lock() 'trick' is used to avoid instrumenting all platform
dependent lock primitive implementations.)It is also possible to toggle the two lockdep features at runtime using:
/proc/sys/kernel/prove_locking
/proc/sys/kernel/lock_stat(esp. turning off the O(n^2) prove_locking functionaliy can help)
[akpm@linux-foundation.org: build fixes]
[akpm@linux-foundation.org: nuke unneeded ifdefs]
Signed-off-by: Peter Zijlstra
Acked-by: Ingo Molnar
Acked-by: Jason Baron
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Move code around to get fewer but larger #ifdef sections. Break some
in-function #ifdefs out into their own functions.Signed-off-by: Peter Zijlstra
Acked-by: Ingo Molnar
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Ensure that all of the lock dependency tracking code is under
CONFIG_PROVE_LOCKING. This allows us to use the held lock tracking code for
other purposes.Signed-off-by: Peter Zijlstra
Acked-by: Ingo Molnar
Acked-by: Jason Baron
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Use the lockdep infrastructure to track lock contention and other lock
statistics.It tracks lock contention events, and the first four unique call-sites that
encountered contention.It also measures lock wait-time and hold-time in nanoseconds. The minimum and
maximum times are tracked, as well as a total (which together with the number
of event can give the avg).All statistics are done per lock class, per write (exclusive state) and per read
(shared state).The statistics are collected per-cpu, so that the collection overhead is
minimized via having no global cachemisses.This new lock statistics feature is independent of the lock dependency checking
traditionally done by lockdep; it just shares the lock tracking code. It is
also possible to enable both and runtime disabled either component - thereby
avoiding the O(n^2) lock chain walks for instance.This patch:
raw_spinlock_t should not use lockdep (and doesn't) since lockdep itself
relies on it.Signed-off-by: Peter Zijlstra
Acked-by: Ingo Molnar
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Signed-off-by: Jan Harkes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Similar information can easily be obtained with strace -c.
Signed-off-by: Jan Harkes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The sb_info structure only contains a single pointer to the character device,
there is no need for the added indirection.Signed-off-by: Jan Harkes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Signed-off-by: Jan Harkes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Signed-off-by: Jan Harkes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Venus returns an ENOENT error on open, so we shouldn't try to grab the
filehandle for the returned fd.Signed-off-by: Jan Harkes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Signed-off-by: Jan Harkes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Signed-off-by: Jan Harkes
Cc: Al Viro
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
We ignore signals for about 30 seconds to give userspace a chance to see the
upcall. As we did not block signals we ended up in a busy loop for the
remainder of the period when a signal is received.Signed-off-by: Jan Harkes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Make the code that processes upcall responses more straightforward, uncovered
at least one bad assumption. We trusted that vc_inuse would be 0 when upcalls
are aborted, however the device may have been reopened.Signed-off-by: Jan Harkes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
- Make sure device index is not a negative number.
- Unlink queued requests when the device is closed to avoid passing them
to the next opener.Signed-off-by: Jan Harkes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Signed-off-by: Jan Harkes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Set MS_NOATIME flag to avoid unnecessary calls when the coda inode is
accessed.Also, set statfs.f_bsize to 4k. 1k is obviously too small for the suggested
IO size.Signed-off-by: Jan Harkes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
A directory without children may still be busy when it is the cwd for some
process. We can safely remove such a directory because the VFS prevents
further operations. Also we don't need to call d_delete as it is already
called in vfs_rmdir.Signed-off-by: Jan Harkes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The Coda client sets the directory link count to 1 when it isn't sure how many
subdirectories we have. In this case we shouldn't change the link count in
the kernel when a subdirectory is created or removed.Signed-off-by: Jan Harkes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Change the epoch value to forces a refresh instead of clearing the cached
rights mask and block all further accesses to the object.Signed-off-by: Jan Harkes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
When open fails the fd in the response is uninitialized and we ended up taking
a reference on the file struct and never released it.Signed-off-by: Jan Harkes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This change passes the --build-id when linking the kernel and when linking
modules, if ld supports it. This is a new GNU ld option that synthesizes an
ELF note section inside the read-only data. The note in this section contains
unique identifying bits called the "build ID", which are generated so as to be
different for any two linked ELF files that aren't identical. The build ID
can be recovered from stripped files, memory dumps, etc. and used to look up
the original program built, locate debuginfo or other details or history
associated with it. For normal program linking, the compiler passes
--build-id to ld by default, but the option is needed when using ld directly
as we do.Signed-off-by: Roland McGrath
Cc: Andi Kleen
Cc: Paul Mackerras
Cc: Benjamin Herrenschmidt
Cc: Richard Henderson
Cc: Ivan Kokshaysky
Cc: Martin Schwidefsky
Cc: Heiko Carstens
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This patch adds the /sys/kernel/notes magic file. Reading this delivers the
contents of the kernel's .notes section. This lets userland easily glean any
detailed information about the running kernel's build that was stored there at
compile time.Signed-off-by: Roland McGrath
Cc: Andi Kleen
Cc: Paul Mackerras
Cc: Benjamin Herrenschmidt
Cc: Richard Henderson
Cc: Ivan Kokshaysky
Cc: Martin Schwidefsky
Cc: Heiko Carstens
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This changes the s390 linker script to use the asm-generic NOTES macro so that
ELF note sections with SHF_ALLOC set are linked into the kernel image along
with other read-only data. The PT_NOTE also points to their location.This paves the way for putting useful build-time information into ELF notes
that can be found easily later in a kernel memory dump.Signed-off-by: Roland McGrath
Cc: Martin Schwidefsky
Cc: Heiko Carstens
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This changes the powerpc linker script to use the asm-generic NOTES macro so
that ELF note sections with SHF_ALLOC set are linked into the kernel image
along with other read-only data. The PT_NOTE also points to their location.This paves the way for putting useful build-time information into ELF notes
that can be found easily later in a kernel memory dump.Signed-off-by: Roland McGrath
Cc: Paul Mackerras
Cc: Benjamin Herrenschmidt
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This changes the alpha linker script to use the asm-generic NOTES macro so
that ELF note sections with SHF_ALLOC set are linked into the kernel image
along with other read-only data. The PT_NOTE also points to their location.This paves the way for putting useful build-time information into ELF notes
that can be found easily later in a kernel memory dump.Signed-off-by: Roland McGrath
Cc: Richard Henderson
Cc: Ivan Kokshaysky
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This changes the x86_64 linker script to use the asm-generic NOTES macro so
that ELF note sections with SHF_ALLOC set are linked into the kernel image
along with other read-only data. The PT_NOTE also points to their location.This paves the way for putting useful build-time information into ELF notes
that can be found easily later in a kernel memory dump.Signed-off-by: Roland McGrath
Cc: Andi Kleen
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This changes the i386 linker script and the asm-generic macro it uses so that
ELF note sections with SHF_ALLOC set are linked into the kernel image along
with other read-only data. The PT_NOTE also points to their location.This paves the way for putting useful build-time information into ELF notes
that can be found easily later in a kernel memory dump.Signed-off-by: Roland McGrath
Cc: Andi Kleen
Cc: Paul Mackerras
Cc: Benjamin Herrenschmidt
Cc: Richard Henderson
Cc: Ivan Kokshaysky
Cc: Martin Schwidefsky
Cc: Heiko Carstens
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Looking at the current linus-git tree jbd_debug() define in
include/linux/jbd2.hextern u8 journal_enable_debug;
#define jbd_debug(n, f, a...) \
do { \
if ((n) fs/ext4/inode.c: In function âext4_write_inodeâ:
> fs/ext4/inode.c:2906: warning: comparison is always true due to limited
> range of data type
>
> fs/jbd2/recovery.c: In function âjbd2_journal_recoverâ:
> fs/jbd2/recovery.c:254: warning: comparison is always true due to
> limited range of data type
> fs/jbd2/recovery.c:257: warning: comparison is always true due to
> limited range of data type
>
> fs/jbd2/recovery.c: In function âjbd2_journal_skip_recoveryâ:
> fs/jbd2/recovery.c:301: warning: comparison is always true due to
> limited range of data type
>
Noticed all warnings are occurs when the debug level is 0. Then found
the "jbd2: Move jbd2-debug file to debugfs" patch
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=0f49d5d019afa4e94253bfc92f0daca3badb990bchanged the jbd2_journal_enable_debug from int type to u8, makes the
jbd_debug comparision is always true when the debugging level is 0. Thus
the compile warning occurs.Thought about changing the jbd2_journal_enable_debug data type back to
int, but can't, because the jbd2-debug is moved to debug fs, where
calling debugfs_create_u8() to create the debugfs entry needs the value
to be u8 type.Even if we changed the data type back to int, the code is still buggy,
kernel should not print jbd2 debug message if the
jbd2_journal_enable_debug is set to 0. But this is not the case.The fix is change the level of debugging to 1. The same should fixed in
ext3/JBD, but currently ext3 jbd-debug via /proc fs is broken, so we
probably should fix it all together.Signed-off-by: Mingming Cao
Cc: Jeff Garzik
Cc: Theodore Tso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This version brings a number of new checks, and a number of bug
fixes. Of note:- warnings for multiple assignments per line
- warnings for multiple declarations per line
- checks for single statement blocks with bracesThis patch includes an update for feature-removal-schedule.txt to
better target checks.Andy Whitcroft (12):
Version: 0.08
only apply printk checks where there is a string literal
allow suppression of errors for when no patch is found
warn about multiple assignments
warn on declaration of multiple variables
check for kfree() with needless null check
check for single statement braced blocks
check for aggregate initialisation on the next line
handle the => operator
check for spaces between function name and open parenthesis
move to explicit Check: entries in feature-removal-schedule.txt
handle pointer attributesSigned-off-by: Andy Whitcroft
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Signed-off-by: Rolf Eike Beer
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
