Currently any ctx_sched_in() call will re-start the ctx time tracking,
this means that calls like:
ctx_sched_in(.event_type = EVENT_PINNED);
ctx_sched_in(.event_type = EVENT_FLEXIBLE);
will have a hole in their ctx time tracking. This is likely harmless
but can confuse things a little. By adding EVENT_TIME, we can have the
first ctx_sched_in() (is_active: 0 -> !0) start the time and any
further ctx_sched_in() will leave the timestamps alone.
Secondly, this allows for an early disable like:
ctx_sched_out(.event_type = EVENT_TIME);
which would update the ctx time (if the ctx is active) and any further
calls to ctx_sched_out() would not further modify the ctx time.
For ctx_sched_in() any 0 -> !0 transition will automatically include
EVENT_TIME.
For ctx_sched_out(), any transition that clears EVENT_ALL will
automatically clear EVENT_TIME.
These two rules ensure that under normal circumstances we need not
bother with EVENT_TIME and get natural ctx time behaviour.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dvyukov@google.com
Cc: eranian@google.com
Cc: oleg@redhat.com
Cc: panand@redhat.com
Cc: sasha.levin@oracle.com
Cc: vince@deater.net
Link: http://lkml.kernel.org/r/20160224174948.100446561@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
perf_install_in_context() relies upon the context switch hooks to have
scheduled in events when the IPI misses its target -- after all, if
the task has moved from the CPU (or wasn't running at all), it will
have to context switch to run elsewhere.
This however doesn't appear to be happening.
It is possible for the IPI to not happen (task wasn't running) only to
later observe the task running with an inactive context.
The only possible explanation is that the context switch hooks are not
called. Therefore put in a sync_sched() after toggling the jump_label
to guarantee all CPUs will have them enabled before we install an
event.
A simple if (0->1) sync_sched() will not in fact work, because any
further increment can race and complete before the sync_sched().
Therefore we must jump through some hoops.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dvyukov@google.com
Cc: eranian@google.com
Cc: oleg@redhat.com
Cc: panand@redhat.com
Cc: sasha.levin@oracle.com
Cc: vince@deater.net
Link: http://lkml.kernel.org/r/20160224174947.980211985@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Alexander reported that when the 'original' context gets destroyed, no
new clones happen.
This can happen irrespective of the ctx switch optimization, any task
can die, even the parent, and we want to continue monitoring the task
hierarchy until we either close the event or no tasks are left in the
hierarchy.
perf_event_init_context() will attempt to pin the 'parent' context
during clone(). At that point current is the parent, and since current
cannot have exited while executing clone(), its context cannot have
passed through perf_event_exit_task_context(). Therefore
perf_pin_task_context() cannot observe ctx->task == TASK_TOMBSTONE.
However, since inherit_event() does:
if (parent_event->parent)
parent_event = parent_event->parent;
it looks at the 'original' event when it does: is_orphaned_event().
This can return true if the context that contains the this event has
passed through perf_event_exit_task_context(). And thus we'll fail to
clone the perf context.
Fix this by adding a new state: STATE_DEAD, which is set by
perf_release() to indicate that the filedesc (or kernel reference) is
dead and there are no observers for our data left.
Only for STATE_DEAD will is_orphaned_event() be true and inhibit
cloning.
STATE_EXIT is otherwise preserved such that is_event_hup() remains
functional and will report when the observed task hierarchy becomes
empty.
Reported-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Tested-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dvyukov@google.com
Cc: eranian@google.com
Cc: oleg@redhat.com
Cc: panand@redhat.com
Cc: sasha.levin@oracle.com
Cc: vince@deater.net
Fixes: c6e5b73242 ("perf: Synchronously clean up child events")
Link: http://lkml.kernel.org/r/20160224174947.919845295@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull ARC fixes from Vineet Gupta:
- Fix for csd deadlock due to missing self IPI
- Accompanying IPI cleanups / optimization
- Brown paper bag bug in one of the cleanups above
- Boot reporting updates for new hardware features
- Don't force DEVTMPFS if INITRAMFS
* tag 'arc-4.5-rc6-fixes-upd' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
arc: SMP: CONFIG_ARC_IPI_DBG cleanup
ARC: SMP: No need for CONFIG_ARC_IPI_DBG
ARCv2: Elide sending new cross core intr if receiver didn't ack prev
ARCv2: SMP: Push IPI_IRQ into IPI provider
ARC: [intc-compact] Remove IPI setup from ARCompact port
ARCv2: SMP: Emulate IPI to self using software triggered interrupt
arc: get rid of DEVTMPFS dependency on INITRAMFS_SOURCE
ARCv2: boot report CCMs (Closely Coupled Memories)
ARCv2: boot print Low Latency Memory
ARC: Assume multiplier is always present
Pull vfs fixes from Al Viro:
"Assorted fixes - xattr one from this cycle, the rest - stable fodder"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
fs/pnode.c: treat zero mnt_group_id-s as unequal
affs_do_readpage_ofs(): just use kmap_atomic() around memcpy()
xattr handlers: plug a lock leak in simple_xattr_list
fs: allow no_seek_end_llseek to actually seek
Previous Commit ("ARC: SMP: No need for CONFIG_ARC_IPI_DBG") removed
the Kconfig option ARC_IPI_DBG. Remove the last reference on this
option.
Signed-off-by: Valentin Rothberg <valentinrothberg@gmail.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
ARConnect/MCIP IPI sending has a retry-wait loop in case caller had
not seen a previous such interrupt. Turns out that it is not needed at
all. Linux cross core calling allows coalescing multiple IPIs to same
receiver - it is fine as long as there is one.
This logic is built into upper layer already, at a higher level of
abstraction. ipi_send_msg_one() sets the actual msg payload, but it only
calls MCIP IPI sending if msg holder was empty (using
atomic-set-new-and-get-old construct). Thus it is unlikely that the
retry-wait looping was ever getting exercised at all.
Cc: Chuck Jordan <cjordan@synopsys.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
There is no real ARC700 based SMP SoC so remove IPI definition.
EZChip's SMP ARC700 is going to use a different intc and IPI provider
anyways.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
ARConnect/MCIP Inter-Core-Interrupt module can't send interrupt to
local core. So use core intc capability to trigger software
interrupt to self, using an unsued IRQ #21.
This showed up as csd deadlock with LTP trace_sched on a dual core
system. This test acts as scheduler fuzzer, triggering all sorts of
schedulting activity. Trouble starts with IPI to self, which doesn't get
delivered (effectively lost due to H/w capability), but the msg intended
to be sent remain enqueued in per-cpu @ipi_data.
All subsequent IPIs to this core from other cores get elided due to the
IPI coalescing optimization in ipi_send_msg_one() where a pending msg
implies an IPI already sent and assumes other core is yet to ack it.
After the elided IPI, other core simply goes into csd_lock_wait()
but never comes out as this core never sees the interrupt.
Fixes STAR 9001008624
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: <stable@vger.kernel.org> [4.2]
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Pull device mapper fix from Mike Snitzer:
"Fix a 112 byte leak for each IO request that is requeued while DM
multipath is handling faults due to path failures.
This leak does not happen if blk-mq DM multipath is used. It only
occurs if .request_fn DM multipath is stacked ontop of blk-mq paths
(e.g. scsi-mq devices)"
* tag 'dm-4.5-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
dm: fix dm_rq_target_io leak on faults with .request_fn DM w/ blk-mq paths
Pull MMC fix from Ulf Hansson:
"Here's an mmc fix intended for v4.5 rc6.
MMC host:
- omap_hsmmc: Fix PM regression for deferred probe"
* tag 'mmc-v4.5-rc4' of git://git.linaro.org/people/ulf.hansson/mmc:
mmc: omap_hsmmc: Fix PM regression with deferred probe for pm_runtime_reinit
Pull NFS client bugfixes from Trond Myklebust:
"Stable bugfixes:
- Fix nfs_size_to_loff_t
- NFSv4: Fix a dentry leak on alias use
Other bugfixes:
- Don't schedule a layoutreturn if the layout segment can be freed
immediately.
- Always set NFS_LAYOUT_RETURN_REQUESTED with lo->plh_return_iomode
- rpcrdma_bc_receive_call() should init rq_private_buf.len
- fix stateid handling for the NFS v4.2 operations
- pnfs/blocklayout: fix a memeory leak when using,vmalloc_to_page
- fix panic in gss_pipe_downcall() in fips mode
- Fix a race between layoutget and pnfs_destroy_layout
- Fix a race between layoutget and bulk recalls"
* tag 'nfs-for-4.5-4' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
NFSv4.x/pnfs: Fix a race between layoutget and bulk recalls
NFSv4.x/pnfs: Fix a race between layoutget and pnfs_destroy_layout
auth_gss: fix panic in gss_pipe_downcall() in fips mode
pnfs/blocklayout: fix a memeory leak when using,vmalloc_to_page
nfs4: fix stateid handling for the NFS v4.2 operations
NFSv4: Fix a dentry leak on alias use
xprtrdma: rpcrdma_bc_receive_call() should init rq_private_buf.len
pNFS: Always set NFS_LAYOUT_RETURN_REQUESTED with lo->plh_return_iomode
pNFS: Fix pnfs_mark_matching_lsegs_return()
nfs: fix nfs_size_to_loff_t
In commit 11f1a4b975 ("x86: reorganize SMAP handling in user space
accesses") I changed how the stac/clac instructions were generated
around the user space accesses, which then made it possible to do
batched accesses efficiently for user string copies etc.
However, in doing so, I completely spaced out, and didn't even think
about the 32-bit case. And nobody really even seemed to notice, because
SMAP doesn't even exist until modern Skylake processors, and you'd have
to be crazy to run 32-bit kernels on a modern CPU.
Which brings us to Andy Lutomirski.
He actually tested the 32-bit kernel on new hardware, and noticed that
it doesn't work. My bad. The trivial fix is to add the required
uaccess begin/end markers around the raw accesses in <asm/uaccess_32.h>.
I feel a bit bad about this patch, just because that header file really
should be cleaned up to avoid all the duplicated code in it, and this
commit just expands on the problem. But this just fixes the bug without
any bigger cleanup surgery.
Reported-and-tested-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Even though DEVTMPFS is required when our pre-built initramfs
is used it is not the case in general. It is perfectly possible
to use initramfs with device nodes already populated or there
could be other usages, see discussion below for more detials:
http://thread.gmane.org/gmane.comp.embedded.openwrt.devel/37819/focus=37821
This change removes mentioned dependency from arch/arc/Kconfig
updating instead those defconfigs that are usually used with this
kind of pre-build initramfs.
And while at it all touched defconfigs were regenerated via
savedefconfig and some options were removed:
* USB is selected by other options implicitly
* VGA_CONSOLE is disableb for ARC since
031e29b587
* EXT3_FS automatically selects EXT4_FS
* MTDxxx and JFFS2_FS make no sense for AXS because
AXS NAND controller is not upstreamed
* NET_OSCI_LAN is not in upstream as well
* ARCPGU_xxx options make no sense because ARC PGU is not yet
in upstream and when it gets there all config options would
be taken from devicetree
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Replace another case where the layout 'plh_block_lgets' can trigger
infinite loops in send_layoutget().
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
If the server reboots while there is a layoutget outstanding, then
the call to pnfs_choose_layoutget_stateid() will fail with an EAGAIN
error, which causes an infinite loop in send_layoutget(). The reason
why we never break out of the loop is that the layout 'plh_block_lgets'
field is never cleared.
Fix is to replace plh_block_lgets with NFS_LAYOUT_INVALID_STID, which
can be reset after a new layoutget.
Fixes: ab7d763e47 ("pNFS: Ensure nfs4_layoutget_prepare returns...")
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Peter Zijlstra
Linus Torvalds
Kirill A. Shutemov
Valentin Rothberg
Vineet Gupta
Alexey Brodkin
Trond Myklebust