13 Sep, 2011

1 commit

  • The oprofilefs_lock can be taken in atomic context (in profiling
    interrupts) and therefore cannot cannot be preempted on -rt -
    annotate it.

    In mainline this change documents the low level nature of
    the lock - otherwise there's no functional difference. Lockdep
    and Sparse checking will work as usual.

    Signed-off-by: Thomas Gleixner
    Signed-off-by: Ingo Molnar

    Thomas Gleixner
     

27 Jul, 2011

1 commit

  • This allows us to move duplicated code in
    (atomic_inc_not_zero() for now) to

    Signed-off-by: Arun Sharma
    Reviewed-by: Eric Dumazet
    Cc: Ingo Molnar
    Cc: David Miller
    Cc: Eric Dumazet
    Acked-by: Mike Frysinger
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Arun Sharma
     

22 Jul, 2011

1 commit


01 Jul, 2011

1 commit

  • The perf_event overflow handler does not receive any caller-derived
    argument, so many callers need to resort to looking up the perf_event
    in their local data structure. This is ugly and doesn't scale if a
    single callback services many perf_events.

    Fix by adding a context parameter to perf_event_create_kernel_counter()
    (and derived hardware breakpoints APIs) and storing it in the perf_event.
    The field can be accessed from the callback as event->overflow_handler_context.
    All callers are updated.

    Signed-off-by: Avi Kivity
    Signed-off-by: Peter Zijlstra
    Link: http://lkml.kernel.org/r/1309362157-6596-2-git-send-email-avi@redhat.com
    Signed-off-by: Ingo Molnar

    Avi Kivity
     

31 May, 2011

2 commits

  • This fixes the A->B/B->A locking dependency, see the warning below.

    The function task_exit_notify() is called with (task_exit_notifier)
    .rwsem set and then calls sync_buffer() which locks buffer_mutex. In
    sync_start() the buffer_mutex was set to prevent notifier functions to
    be started before sync_start() is finished. But when registering the
    notifier, (task_exit_notifier).rwsem is locked too, but now in
    different order than in sync_buffer(). In theory this causes a locking
    dependency, what does not occur in practice since task_exit_notify()
    is always called after the notifier is registered which means the lock
    is already released.

    However, after checking the notifier functions it turned out the
    buffer_mutex in sync_start() is unnecessary. This is because
    sync_buffer() may be called from the notifiers even if sync_start()
    did not finish yet, the buffers are already allocated but empty. No
    need to protect this with the mutex.

    So we fix this theoretical locking dependency by removing buffer_mutex
    in sync_start(). This is similar to the implementation before commit:

    750d857 oprofile: fix crash when accessing freed task structs

    which introduced the locking dependency.

    Lockdep warning:

    oprofiled/4447 is trying to acquire lock:
    (buffer_mutex){+.+...}, at: [] sync_buffer+0x31/0x3ec [oprofile]

    but task is already holding lock:
    ((task_exit_notifier).rwsem){++++..}, at: [] __blocking_notifier_call_chain+0x39/0x67

    which lock already depends on the new lock.

    the existing dependency chain (in reverse order) is:

    -> #1 ((task_exit_notifier).rwsem){++++..}:
    [] lock_acquire+0xf8/0x11e
    [] down_write+0x44/0x67
    [] blocking_notifier_chain_register+0x52/0x8b
    [] profile_event_register+0x2d/0x2f
    [] sync_start+0x47/0xc6 [oprofile]
    [] oprofile_setup+0x60/0xa5 [oprofile]
    [] event_buffer_open+0x59/0x8c [oprofile]
    [] __dentry_open+0x1eb/0x308
    [] nameidata_to_filp+0x60/0x67
    [] do_last+0x5be/0x6b2
    [] path_openat+0xc7/0x360
    [] do_filp_open+0x3d/0x8c
    [] do_sys_open+0x110/0x1a9
    [] sys_open+0x20/0x22
    [] system_call_fastpath+0x16/0x1b

    -> #0 (buffer_mutex){+.+...}:
    [] __lock_acquire+0x1085/0x1711
    [] lock_acquire+0xf8/0x11e
    [] mutex_lock_nested+0x63/0x309
    [] sync_buffer+0x31/0x3ec [oprofile]
    [] task_exit_notify+0x16/0x1a [oprofile]
    [] notifier_call_chain+0x37/0x63
    [] __blocking_notifier_call_chain+0x50/0x67
    [] blocking_notifier_call_chain+0x14/0x16
    [] profile_task_exit+0x1a/0x1c
    [] do_exit+0x2a/0x6fc
    [] do_group_exit+0x83/0xae
    [] sys_exit_group+0x17/0x1b
    [] system_call_fastpath+0x16/0x1b

    other info that might help us debug this:

    1 lock held by oprofiled/4447:
    #0: ((task_exit_notifier).rwsem){++++..}, at: [] __blocking_notifier_call_chain+0x39/0x67

    stack backtrace:
    Pid: 4447, comm: oprofiled Not tainted 2.6.39-00007-gcf4d8d4 #10
    Call Trace:
    [] print_circular_bug+0xae/0xbc
    [] __lock_acquire+0x1085/0x1711
    [] ? sync_buffer+0x31/0x3ec [oprofile]
    [] lock_acquire+0xf8/0x11e
    [] ? sync_buffer+0x31/0x3ec [oprofile]
    [] ? mark_lock+0x42f/0x552
    [] ? sync_buffer+0x31/0x3ec [oprofile]
    [] mutex_lock_nested+0x63/0x309
    [] ? sync_buffer+0x31/0x3ec [oprofile]
    [] sync_buffer+0x31/0x3ec [oprofile]
    [] ? __blocking_notifier_call_chain+0x39/0x67
    [] ? __blocking_notifier_call_chain+0x39/0x67
    [] task_exit_notify+0x16/0x1a [oprofile]
    [] notifier_call_chain+0x37/0x63
    [] __blocking_notifier_call_chain+0x50/0x67
    [] blocking_notifier_call_chain+0x14/0x16
    [] profile_task_exit+0x1a/0x1c
    [] do_exit+0x2a/0x6fc
    [] ? retint_swapgs+0xe/0x13
    [] do_group_exit+0x83/0xae
    [] sys_exit_group+0x17/0x1b
    [] system_call_fastpath+0x16/0x1b

    Reported-by: Marcin Slusarz
    Cc: Carl Love
    Cc: # .36+
    Signed-off-by: Robert Richter

    Robert Richter
     
  • After registering the task free notifier we possibly have tasks in our
    dying_tasks list. Free them after unregistering the notifier in case
    of an error.

    Cc: # .36+
    Signed-off-by: Robert Richter

    Robert Richter
     

24 May, 2011

1 commit


15 Feb, 2011

3 commits

  • This patch is a rework of the hwsampler oprofile implementation that
    has been applied recently. Now there are less non-architectural
    changes. The only changes are:

    * introduction of oprofile_add_ext_hw_sample(), and
    * removal of section attributes of oprofile_timer_init/_exit().

    To setup hwsampler for oprofile we need to modify start()/stop()
    callbacks and additional hwsampler control files in oprofilefs. We do
    not reinitialize the timer or hwsampler mode by restarting calling
    init/exit() anymore, instead hwsampler_running is used to switch the
    mode directly in oprofile_hwsampler_start/_stop(). For locking reasons
    there is also hwsampler_file that reflects the value in oprofilefs.

    The overall diffstat of the oprofile s390 hwsampler implemenation
    shows the low impact to non-architectural code:

    arch/Kconfig | 3 +
    arch/s390/Kconfig | 1 +
    arch/s390/oprofile/Makefile | 2 +-
    arch/s390/oprofile/hwsampler.c | 1256 ++++++++++++++++++++++++++++++++++
    arch/s390/oprofile/hwsampler.h | 113 +++
    arch/s390/oprofile/hwsampler_files.c | 162 +++++
    arch/s390/oprofile/init.c | 6 +-
    drivers/oprofile/cpu_buffer.c | 24 +-
    drivers/oprofile/timer_int.c | 4 +-
    include/linux/oprofile.h | 7 +
    10 files changed, 1567 insertions(+), 11 deletions(-)

    Acked-by: Heiko Carstens
    Signed-off-by: Robert Richter

    Robert Richter
     
  • OProfile is enhanced to export all files for controlling System z's
    hardware sampling, and to invoke hwsampler exported functions to
    initialize and use System z's hardware sampling.

    The patch invokes hwsampler_setup() during oprofile init and exports
    following hwsampler files under oprofilefs if hwsampler's setup
    succeeded:

    A new directory for hardware sampling based files

    /dev/oprofile/hwsampling/

    The userland daemon must explicitly write to the following files
    to disable (or enable) hardware based sampling

    /dev/oprofile/hwsampling/hwsampler

    to modify the actual sampling rate

    /dev/oprofile/hwsampling/hw_interval

    to modify the amount of sampling memory (measured in 4K pages)

    /dev/oprofile/hwsampling/hw_sdbt_blocks

    The following files are read only and show
    the possible minimum sampling rate

    /dev/oprofile/hwsampling/hw_min_interval

    the possible maximum sampling rate

    /dev/oprofile/hwsampling/hw_max_interval

    The patch splits the oprofile_timer_[init/exit] function so that it
    can be also called through user context (oprofilefs) to avoid kernel
    oops.

    Applied with following changes:
    * whitespace changes in Makefile and timer_int.c

    Signed-off-by: Mahesh Salgaonkar
    Signed-off-by: Maran Pakkirisamy
    Signed-off-by: Heinz Graalfs
    Acked-by: Heiko Carstens
    Signed-off-by: Robert Richter

    Heinz Graalfs
     
  • This patch introduces a new oprofile sample add function
    (oprofile_add_ext_hw_sample) that can also take task_struct as an
    argument, which is used by the hwsampler kernel module when copying
    hardware samples to OProfile buffers.

    Applied with following changes:
    * removed #include
    * whitespace changes
    * removed conditional compilation (CONFIG_HAVE_HWSAMPLER)
    * modified order of functions
    * fix missing function definition in header file

    Signed-off-by: Mahesh Salgaonkar
    Signed-off-by: Maran Pakkirisamy
    Signed-off-by: Heinz Graalfs
    Acked-by: Heiko Carstens
    Signed-off-by: Robert Richter

    Heinz Graalfs
     

31 Oct, 2010

1 commit

  • …nel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

    * 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
    jump label: Add work around to i386 gcc asm goto bug
    x86, ftrace: Use safe noops, drop trap test
    jump_label: Fix unaligned traps on sparc.
    jump label: Make arch_jump_label_text_poke_early() optional
    jump label: Fix error with preempt disable holding mutex
    oprofile: Remove deprecated use of flush_scheduled_work()
    oprofile: Fix the hang while taking the cpu offline
    jump label: Fix deadlock b/w jump_label_mutex vs. text_mutex
    jump label: Fix module __init section race

    * 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
    x86: Check irq_remapped instead of remapping_enabled in destroy_irq()

    Linus Torvalds
     

30 Oct, 2010

1 commit


29 Oct, 2010

3 commits

  • flush_scheduled_work() is deprecated and scheduled to be removed.
    sync_stop() currently cancels cpu_buffer works inside buffer_mutex and
    flushes the system workqueue outside. Instead, split end_cpu_work()
    into two parts - stopping further work enqueues and flushing works -
    and do the former inside buffer_mutex and latter outside.

    For stable kernels v2.6.35.y and v2.6.36.y.

    Signed-off-by: Tejun Heo
    Cc: stable@kernel.org
    Signed-off-by: Robert Richter

    Tejun Heo
     
  • The kernel build with CONFIG_OPROFILE and CPU_HOTPLUG enabled.
    The oprofile is initialised using system timer in absence of hardware
    counters supports. Oprofile isn't started from userland.

    In this setup while doing a CPU offline the kernel hangs in infinite
    for loop inside lock_hrtimer_base() function

    This happens because as part of oprofile_cpu_notify(, it tries to
    stop an hrtimer which was never started. These per-cpu hrtimers
    are started when the oprfile is started.
    echo 1 > /dev/oprofile/enable

    This problem also existwhen the cpu is booted with maxcpus parameter
    set. When bringing the remaining cpus online the timers are started
    even if oprofile is not yet enabled.

    This patch fix this issue by adding a state variable so that
    these hrtimer start/stop is only attempted when oprofile is
    started

    For stable kernels v2.6.35.y and v2.6.36.y.

    Reported-by: Jan Sebastien
    Tested-by: sricharan
    Signed-off-by: Santosh Shilimkar
    Cc: stable@kernel.org
    Signed-off-by: Robert Richter

    Santosh Shilimkar
     
  • Signed-off-by: Al Viro

    Al Viro
     

26 Oct, 2010

1 commit

  • Instead of always assigning an increasing inode number in new_inode
    move the call to assign it into those callers that actually need it.
    For now callers that need it is estimated conservatively, that is
    the call is added to all filesystems that do not assign an i_ino
    by themselves. For a few more filesystems we can avoid assigning
    any inode number given that they aren't user visible, and for others
    it could be done lazily when an inode number is actually needed,
    but that's left for later patches.

    Signed-off-by: Christoph Hellwig
    Signed-off-by: Dave Chinner
    Signed-off-by: Al Viro

    Christoph Hellwig
     

23 Oct, 2010

1 commit

  • * 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl:
    vfs: make no_llseek the default
    vfs: don't use BKL in default_llseek
    llseek: automatically add .llseek fop
    libfs: use generic_file_llseek for simple_attr
    mac80211: disallow seeks in minstrel debug code
    lirc: make chardev nonseekable
    viotape: use noop_llseek
    raw: use explicit llseek file operations
    ibmasmfs: use generic_file_llseek
    spufs: use llseek in all file operations
    arm/omap: use generic_file_llseek in iommu_debug
    lkdtm: use generic_file_llseek in debugfs
    net/wireless: use generic_file_llseek in debugfs
    drm: use noop_llseek

    Linus Torvalds
     

15 Oct, 2010

5 commits

  • All file_operations should get a .llseek operation so we can make
    nonseekable_open the default for future file operations without a
    .llseek pointer.

    The three cases that we can automatically detect are no_llseek, seq_lseek
    and default_llseek. For cases where we can we can automatically prove that
    the file offset is always ignored, we use noop_llseek, which maintains
    the current behavior of not returning an error from a seek.

    New drivers should normally not use noop_llseek but instead use no_llseek
    and call nonseekable_open at open time. Existing drivers can be converted
    to do the same when the maintainer knows for certain that no user code
    relies on calling seek on the device file.

    The generated code is often incorrectly indented and right now contains
    comments that clarify for each added line why a specific variant was
    chosen. In the version that gets submitted upstream, the comments will
    be gone and I will manually fix the indentation, because there does not
    seem to be a way to do that using coccinelle.

    Some amount of new code is currently sitting in linux-next that should get
    the same modifications, which I will do at the end of the merge window.

    Many thanks to Julia Lawall for helping me learn to write a semantic
    patch that does all this.

    ===== begin semantic patch =====
    // This adds an llseek= method to all file operations,
    // as a preparation for making no_llseek the default.
    //
    // The rules are
    // - use no_llseek explicitly if we do nonseekable_open
    // - use seq_lseek for sequential files
    // - use default_llseek if we know we access f_pos
    // - use noop_llseek if we know we don't access f_pos,
    // but we still want to allow users to call lseek
    //
    @ open1 exists @
    identifier nested_open;
    @@
    nested_open(...)
    {

    }

    @ open exists@
    identifier open_f;
    identifier i, f;
    identifier open1.nested_open;
    @@
    int open_f(struct inode *i, struct file *f)
    {

    }

    @ read disable optional_qualifier exists @
    identifier read_f;
    identifier f, p, s, off;
    type ssize_t, size_t, loff_t;
    expression E;
    identifier func;
    @@
    ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
    {

    }

    @ read_no_fpos disable optional_qualifier exists @
    identifier read_f;
    identifier f, p, s, off;
    type ssize_t, size_t, loff_t;
    @@
    ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
    {
    ... when != off
    }

    @ write @
    identifier write_f;
    identifier f, p, s, off;
    type ssize_t, size_t, loff_t;
    expression E;
    identifier func;
    @@
    ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
    {

    }

    @ write_no_fpos @
    identifier write_f;
    identifier f, p, s, off;
    type ssize_t, size_t, loff_t;
    @@
    ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
    {
    ... when != off
    }

    @ fops0 @
    identifier fops;
    @@
    struct file_operations fops = {
    ...
    };

    @ has_llseek depends on fops0 @
    identifier fops0.fops;
    identifier llseek_f;
    @@
    struct file_operations fops = {
    ...
    .llseek = llseek_f,
    ...
    };

    @ has_read depends on fops0 @
    identifier fops0.fops;
    identifier read_f;
    @@
    struct file_operations fops = {
    ...
    .read = read_f,
    ...
    };

    @ has_write depends on fops0 @
    identifier fops0.fops;
    identifier write_f;
    @@
    struct file_operations fops = {
    ...
    .write = write_f,
    ...
    };

    @ has_open depends on fops0 @
    identifier fops0.fops;
    identifier open_f;
    @@
    struct file_operations fops = {
    ...
    .open = open_f,
    ...
    };

    // use no_llseek if we call nonseekable_open
    ////////////////////////////////////////////
    @ nonseekable1 depends on !has_llseek && has_open @
    identifier fops0.fops;
    identifier nso ~= "nonseekable_open";
    @@
    struct file_operations fops = {
    ... .open = nso, ...
    +.llseek = no_llseek, /* nonseekable */
    };

    @ nonseekable2 depends on !has_llseek @
    identifier fops0.fops;
    identifier open.open_f;
    @@
    struct file_operations fops = {
    ... .open = open_f, ...
    +.llseek = no_llseek, /* open uses nonseekable */
    };

    // use seq_lseek for sequential files
    /////////////////////////////////////
    @ seq depends on !has_llseek @
    identifier fops0.fops;
    identifier sr ~= "seq_read";
    @@
    struct file_operations fops = {
    ... .read = sr, ...
    +.llseek = seq_lseek, /* we have seq_read */
    };

    // use default_llseek if there is a readdir
    ///////////////////////////////////////////
    @ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    identifier readdir_e;
    @@
    // any other fop is used that changes pos
    struct file_operations fops = {
    ... .readdir = readdir_e, ...
    +.llseek = default_llseek, /* readdir is present */
    };

    // use default_llseek if at least one of read/write touches f_pos
    /////////////////////////////////////////////////////////////////
    @ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    identifier read.read_f;
    @@
    // read fops use offset
    struct file_operations fops = {
    ... .read = read_f, ...
    +.llseek = default_llseek, /* read accesses f_pos */
    };

    @ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    identifier write.write_f;
    @@
    // write fops use offset
    struct file_operations fops = {
    ... .write = write_f, ...
    + .llseek = default_llseek, /* write accesses f_pos */
    };

    // Use noop_llseek if neither read nor write accesses f_pos
    ///////////////////////////////////////////////////////////

    @ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    identifier read_no_fpos.read_f;
    identifier write_no_fpos.write_f;
    @@
    // write fops use offset
    struct file_operations fops = {
    ...
    .write = write_f,
    .read = read_f,
    ...
    +.llseek = noop_llseek, /* read and write both use no f_pos */
    };

    @ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    identifier write_no_fpos.write_f;
    @@
    struct file_operations fops = {
    ... .write = write_f, ...
    +.llseek = noop_llseek, /* write uses no f_pos */
    };

    @ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    identifier read_no_fpos.read_f;
    @@
    struct file_operations fops = {
    ... .read = read_f, ...
    +.llseek = noop_llseek, /* read uses no f_pos */
    };

    @ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    @@
    struct file_operations fops = {
    ...
    +.llseek = noop_llseek, /* no read or write fn */
    };
    ===== End semantic patch =====

    Signed-off-by: Arnd Bergmann
    Cc: Julia Lawall
    Cc: Christoph Hellwig

    Arnd Bergmann
     
  • Make !CONFIG_PM function stubs static inline and remove section
    attribute.

    Signed-off-by: Robert Richter

    Robert Richter
     
  • Commit e9677b3ce (oprofile, ARM: Use oprofile_arch_exit() to
    cleanup on failure) caused oprofile_perf_exit to be called
    in the cleanup path of oprofile_perf_init. The __exit tag
    for oprofile_perf_exit should therefore be dropped.

    The same has to be done for exit_driverfs as well, as this
    function is called from oprofile_perf_exit. Else, we get
    the following two linker errors.

    LD .tmp_vmlinux1
    `oprofile_perf_exit' referenced in section `.init.text' of arch/arm/oprofile/built-in.o: defined in discarded section `.exit.text' of arch/arm/oprofile/built-in.o
    make: *** [.tmp_vmlinux1] Error 1

    LD .tmp_vmlinux1
    `exit_driverfs' referenced in section `.text' of arch/arm/oprofile/built-in.o: defined in discarded section `.exit.text' of arch/arm/oprofile/built-in.o
    make: *** [.tmp_vmlinux1] Error 1

    Signed-off-by: Anand Gadiyar
    Cc: Will Deacon
    Signed-off-by: Robert Richter

    Anand Gadiyar
     
  • oprofile_perf.c needs to include platform_device.h
    Otherwise we get the following build break.

    CC arch/arm/oprofile/../../../drivers/oprofile/oprofile_perf.o
    arch/arm/oprofile/../../../drivers/oprofile/oprofile_perf.c:192: warning: 'struct platform_device' declared inside parameter list
    arch/arm/oprofile/../../../drivers/oprofile/oprofile_perf.c:192: warning: its scope is only this definition or declaration, which is probably not what you want
    arch/arm/oprofile/../../../drivers/oprofile/oprofile_perf.c:201: warning: 'struct platform_device' declared inside parameter list
    arch/arm/oprofile/../../../drivers/oprofile/oprofile_perf.c:210: error: variable 'oprofile_driver' has initializer but incomplete type
    arch/arm/oprofile/../../../drivers/oprofile/oprofile_perf.c:211: error: unknown field 'driver' specified in initializer
    arch/arm/oprofile/../../../drivers/oprofile/oprofile_perf.c:211: error: extra brace group at end of initializer
    arch/arm/oprofile/../../../drivers/oprofile/oprofile_perf.c:211: error: (near initialization for 'oprofile_driver')
    arch/arm/oprofile/../../../drivers/oprofile/oprofile_perf.c:213: warning: excess elements in struct initializer
    arch/arm/oprofile/../../../drivers/oprofile/oprofile_perf.c:213: warning: (near initialization for 'oprofile_driver')
    arch/arm/oprofile/../../../drivers/oprofile/oprofile_perf.c:214: error: unknown field 'resume' specified in initializer
    arch/arm/oprofile/../../../drivers/oprofile/oprofile_perf.c:214: warning: excess elements in struct initializer
    arch/arm/oprofile/../../../drivers/oprofile/oprofile_perf.c:214: warning: (near initialization for 'oprofile_driver')
    arch/arm/oprofile/../../../drivers/oprofile/oprofile_perf.c:215: error: unknown field 'suspend' specified in initializer
    arch/arm/oprofile/../../../drivers/oprofile/oprofile_perf.c:215: warning: excess elements in struct initializer
    arch/arm/oprofile/../../../drivers/oprofile/oprofile_perf.c:215: warning: (near initialization for 'oprofile_driver')
    arch/arm/oprofile/../../../drivers/oprofile/oprofile_perf.c: In function 'init_driverfs':

    Signed-off-by: Anand Gadiyar
    Cc: Matt Fleming
    Cc: Will Deacon
    Signed-off-by: Robert Richter

    Anand Gadiyar
     
  • Conflicts:
    arch/arm/oprofile/common.c
    kernel/perf_event.c

    Robert Richter
     

12 Oct, 2010

7 commits


11 Oct, 2010

1 commit

  • Move the perf-events backend from arch/arm/oprofile into
    drivers/oprofile so that the code can be shared between architectures.

    This allows each architecture to maintain only a single copy of the PMU
    accessor functions instead of one for both perf and OProfile. It also
    becomes possible for other architectures to delete much of their
    OProfile code in favour of the common code now available in
    drivers/oprofile/oprofile_perf.c.

    Signed-off-by: Matt Fleming
    Tested-by: Will Deacon
    Signed-off-by: Robert Richter

    Matt Fleming
     

04 Oct, 2010

1 commit


01 Oct, 2010

1 commit


31 Aug, 2010

1 commit

  • oprofile_init calls oprofile_arch_init to initialise the architecture-specific
    backend code. If this backend code returns failure, oprofile_arch_exit is
    called immediately, making it difficult to allocate and free resources
    correctly.

    This patch removes the oprofile_arch_exit call from oprofile_init,
    meaning that all architectures must ensure that oprofile_arch_init
    cleans up any mess it's made before returning an error. As far as
    I can tell, this only affects the code for ARM.

    Cc: Robert Richter
    Cc: Matt Fleming
    Cc: Peter Zijlstra
    Cc: Ingo Molnar
    Signed-off-by: Will Deacon
    Signed-off-by: Robert Richter

    Will Deacon
     

25 Aug, 2010

1 commit

  • This patch fixes a crash during shutdown reported below. The crash is
    caused by accessing already freed task structs. The fix changes the
    order for registering and unregistering notifier callbacks.

    All notifiers must be initialized before buffers start working. To
    stop buffer synchronization we cancel all workqueues, unregister the
    notifier callback and then flush all buffers. After all of this we
    finally can free all tasks listed.

    This should avoid accessing freed tasks.

    On 22.07.10 01:14:40, Benjamin Herrenschmidt wrote:

    > So the initial observation is a spinlock bad magic followed by a crash
    > in the spinlock debug code:
    >
    > [ 1541.586531] BUG: spinlock bad magic on CPU#5, events/5/136
    > [ 1541.597564] Unable to handle kernel paging request for data at address 0x6b6b6b6b6b6b6d03
    >
    > Backtrace looks like:
    >
    > spin_bug+0x74/0xd4
    > ._raw_spin_lock+0x48/0x184
    > ._spin_lock+0x10/0x24
    > .get_task_mm+0x28/0x8c
    > .sync_buffer+0x1b4/0x598
    > .wq_sync_buffer+0xa0/0xdc
    > .worker_thread+0x1d8/0x2a8
    > .kthread+0xa8/0xb4
    > .kernel_thread+0x54/0x70
    >
    > So we are accessing a freed task struct in the work queue when
    > processing the samples.

    Reported-by: Benjamin Herrenschmidt
    Cc: stable@kernel.org
    Signed-off-by: Robert Richter

    Robert Richter
     

26 Jul, 2010

1 commit


04 May, 2010

1 commit

  • http://lkml.org/lkml/2010/4/27/285

    Protect against dereferencing regs when it's NULL, and
    force a magic number into pc to prevent too deep processing.
    This approach permits the dropped samples to be tallied as
    invalid Instruction Pointer events.

    e.g. output from about 15mins at 10kHz sample rate:
    Nr. samples received: 2565380
    Nr. samples lost invalid pc: 4

    Signed-off-by: Phil Carmody
    Signed-off-by: Robert Richter

    Phil Carmody
     

23 Apr, 2010

3 commits


08 Apr, 2010

1 commit

  • Conflicts:
    include/linux/module.h
    kernel/module.c

    Semantic conflict:
    include/trace/events/module.h

    Merge reason: Resolve the conflict with upstream commit 5fbfb18 ("Fix up
    possibly racy module refcounting")

    Signed-off-by: Ingo Molnar

    Ingo Molnar