Impact: enhance boot trace output with scheduling events
Use the sched_switch tracer from the boot tracer.
We also can trace schedule events inside the initcalls.
Sched tracing is disabled after the initcall has finished and
then reenabled before the next one is started.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup
When init_sched_switch_trace() is called, it has no reason to start
the sched tracer if the sched_ref is not zero.
_ If this is non-zero, the tracer is already used, but we can register it
to the tracing engine. There is already a security which avoid the tracer
probes not to be resgistered twice.
_ If this is zero, this block will not be used.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: fix race condition in sched_switch tracer
This patch fixes a race condition in the sched_switch tracer. If
several tasks (IE: concurrent initcalls) are playing with
tracing_start_cmdline_record() and tracing_stop_cmdline_record(), the
following situation could happen:
_ Task A and B are using the same tracepoint probe. Task A holds it.
Task B is sleeping and doesn't hold it.
_ Task A frees the sched tracer, then sched_ref is decremented to 0.
_ Task A is preempted and hadn't yet unregistered its tracepoint
probe, then B runs.
_ B increments sched_ref, sees it's 1 and then guess it has to
register its probe. But it has not been freed by task A.
_ A lot of bad things can happen after that...
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: modify boot tracer
We used to disable the initcall tracing at a specified time (IE: end
of builtin initcalls). But we don't need it anymore. It will be
stopped when initcalls are finished.
However we want two things:
_Start this tracing only after pre-smp initcalls are finished.
_Since we are planning to trace sched_switches at the same time, we
want to enable them only during the initcall execution.
For this purpose, this patch introduce two functions to enable/disable
the sched_switch tracing during boot.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: add new tracepoint APIs to allow the batched registration of probes
new APIs separate tracepoint_probe_register(),
tracepoint_probe_unregister() into 2 steps. The first step of them
is just update tracepoint_entry, not connect or disconnect.
this patch introduces tracepoint_probe_update_all() for update all.
these APIs are very useful for registering lots of probes
but just updating once. Another very important thing is that
*_noupdate APIs do not require module_mutex.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: simplify implementation
Now, unused memory is handled by struct tp_probes.
old code use these three field to handle unused memory.
struct tracepoint_entry {
...
struct rcu_head rcu;
void *oldptr;
unsigned char rcu_pending:1;
...
};
in this way, unused memory is handled by struct tracepoint_entry.
it bring reenter bug(it was fixed) and tracepoint.c is filled
full of ".*rcu.*" code statements. this patch removes all these.
and:
rcu_barrier_sched() is removed.
Do not need regain tracepoints_mutex after tracepoint_update_probes()
several little cleanup.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: build fix on !stacktrace architectures
only select STACKTRACE on architectures that have STACKTRACE_SUPPORT
... since we also need to ifdef out the guts of ftrace_trace_stack().
We also want to disallow setting TRACE_ITER_STACKTRACE in trace_flags
on such configs, but that can wait.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: add new (optional) debug boot option
In order to facilitate early boot trouble, allow one to specify a tracer
on the kernel boot line.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* git://git.kernel.org/pub/scm/linux/kernel/git/bart/ide-2.6:
ide-gd: re-get capacity on revalidate
tx4938ide: Avoid underflow on calculation of a wait cycle
tx4938ide: Do not call devm_ioremap for whole 128KB
tx4938ide: Check minimum cycle time and SHWT range (v2)
ide: Switch to a common address
ide-cd: fix DMA alignment regression
We need to re-get a removable media's capacity when revalidating the
disk so that its partitions get rescanned by the block layer.
Signed-off-by: Borislav Petkov <petkovbb@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: axboe@kernel.dk
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
SHWT value is used as address valid to -CSx assertion and -CSx to -DIOx
assertion setup time, and contrarywise, -DIOx to -CSx release and -CSx
release to address invalid hold time, so it actualy applies 4 times and
so constitutes -DIOx recovery time. Check requirement of the recovery
time and cycle time. Also check SHWT maximum value.
Suggested-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: ralf@linux-mips.org
Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
e5318b531b ("ide: use the dma safe check for
REQ_TYPE_ATA_PC") introduced a regression which caused some ATAPI drives to
turn off DMA for REQ_TYPE_BLOCK_PC commands while burning and thus degrading
performance and ultimately causing an excessive amount of underruns.
The issue is documented also in:
http://bugzilla.kernel.org/show_bug.cgi?id=11742.
Signed-off-by: Borislav Petkov <petkovbb@gmail.com>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Tested-by: Valerio Passini <valerio.passini@unicam.it>
[bart: fixup patch description per comments from Sergei Shtylyov]
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (33 commits)
af_unix: netns: fix problem of return value
IRDA: remove double inclusion of module.h
udp: multicast packets need to check namespace
net: add documentation for skb recycling
key: fix setkey(8) policy set breakage
bpa10x: free sk_buff with kfree_skb
xfrm: do not leak ESRCH to user space
net: Really remove all of LOOPBACK_TSO code.
netfilter: nf_conntrack_proto_gre: switch to register_pernet_gen_subsys()
netns: add register_pernet_gen_subsys/unregister_pernet_gen_subsys
net: delete excess kernel-doc notation
pppoe: Fix socket leak.
gianfar: Don't reset TBI<->SerDes link if it's already up
gianfar: Fix race in TBI/SerDes configuration
at91_ether: request/free GPIO for PHY interrupt
amd8111e: fix dma_free_coherent context
atl1: fix vlan tag regression
SMC91x: delete unused local variable "lp"
myri10ge: fix stop/go mmio ordering
bonding: fix panic when taking bond interface down before removing module
...
There is a problem discovered in recent versions of ATI Mach64 driver
in X.org on sparc64 architecture. In short, the driver fails to mmap
MMIO aperture (PCI resource #2).
I've found that kernel's __pci_mmap_make_offset() returns EINVAL. It
checks whether user attempts to mmap more than the resource length,
which is 0x1000 bytes in our case. But PAGE_SIZE on SPARC64 is 0x2000
and this is what actually is being mmaped. So __pci_mmap_make_offset()
failed for this PCI resource.
Signed-off-by: Max Dmitrichenko <dmitrmax@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
GCC warns because some tests against 32-bit values never evaluate to
true due to how TASK_SIZE is defined.
I always wanted to mimick powerpc's definition of TASK_SIZE, which
is simply TASK_SIZE_OF(current) and that also fixes the warning.
Signed-off-by: David S. Miller <davem@davemloft.net>
Alexander Beregalov reports oops in __bzero() called from
copy_from_user_fixup() called from iov_iter_copy_from_user_atomic(),
when running dbench on tmpfs on sparc64: its __copy_from_user_inatomic
and __copy_to_user_inatomic should be avoiding, not calling, the fixups.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
