21 May, 2010
5 commits
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Reduce code and data by using the knowledge that for
!PERF_USE_VMALLOC data_order is always 0.Signed-off-by: Peter Zijlstra
Cc: Arnaldo Carvalho de Melo
Cc: Frederic Weisbecker
Cc: Paul Mackerras
Cc: Mike Galbraith
Cc: Steven Rostedt
LKML-Reference:
Signed-off-by: Ingo Molnar -
Reduce the clutter in perf_output_copy() by keeping
an interator in perf_output_handle.Signed-off-by: Peter Zijlstra
Cc: Arnaldo Carvalho de Melo
Cc: Frederic Weisbecker
Cc: Paul Mackerras
Cc: Mike Galbraith
Cc: Steven Rostedt
LKML-Reference:
Signed-off-by: Ingo Molnar -
RO mmap()s don't update the tail pointer, so
comparing against it for determining the written data
size doesn't really do any good.Keep track of when we last did a wakeup, and compare
against that.Signed-off-by: Peter Zijlstra
Cc: Arnaldo Carvalho de Melo
Cc: Frederic Weisbecker
Cc: Paul Mackerras
Cc: Mike Galbraith
Cc: Steven Rostedt
LKML-Reference:
Signed-off-by: Ingo Molnar -
Avoid the swevent hash-table by using per-tracepoint
hlists.Also, avoid conditionals on the fast path by ordering
with probe unregister so that we should never get on
the callback path without the data being there.Signed-off-by: Peter Zijlstra
Cc: Arnaldo Carvalho de Melo
Cc: Frederic Weisbecker
Cc: Paul Mackerras
Cc: Mike Galbraith
Cc: Steven Rostedt
LKML-Reference:
Signed-off-by: Ingo Molnar -
Improves performance.
Acked-by: Frederic Weisbecker
Signed-off-by: Peter Zijlstra
Cc: Arnaldo Carvalho de Melo
Cc: Frederic Weisbecker
Cc: Paul Mackerras
Cc: Mike Galbraith
Cc: Steven Rostedt
LKML-Reference:
Signed-off-by: Ingo Molnar
20 May, 2010
1 commit
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…eric/random-tracing into perf/core
19 May, 2010
7 commits
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Since the x86 XCHG ins implies LOCK, avoid the use by
using a sequence count instead.Signed-off-by: Peter Zijlstra
LKML-Reference:
Signed-off-by: Ingo Molnar -
Since there is now only a single writer, we can use
local_t instead and avoid all these pesky LOCK insn.Signed-off-by: Peter Zijlstra
LKML-Reference:
Signed-off-by: Ingo Molnar -
Since we can now assume there is only a single writer
to each buffer, we can remove per-cpu lock thingy and
use a simply nest-count to the same effect.This removes the need to disable IRQs.
Signed-off-by: Peter Zijlstra
Cc: Mike Galbraith
Cc: Paul Mackerras
Cc: Arnaldo Carvalho de Melo
Cc: Frederic Weisbecker
LKML-Reference:
Signed-off-by: Ingo Molnar -
When we've got but a single event per tracepoint
there is no reason to try and multiplex it so don't.Signed-off-by: Peter Zijlstra
Tested-by: Ingo Molnar
Cc: Steven Rostedt
Cc: Frederic Weisbecker
Cc: Mike Galbraith
Cc: Paul Mackerras
Cc: Arnaldo Carvalho de Melo
LKML-Reference:
Signed-off-by: Ingo Molnar -
* 'x86-pat-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, pat: Update the page flags for memtype atomically instead of using memtype_lock
x86, pat: In rbt_memtype_check_insert(), update new->type only if valid
x86, pat: Migrate to rbtree only backend for pat memtype management
x86, pat: Preparatory changes in pat.c for bigger rbtree change
rbtree: Add support for augmented rbtrees -
…el/git/tip/linux-2.6-tip
* 'core-hweight-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, hweight: Use a 32-bit popcnt for __arch_hweight32()
arch, hweight: Fix compilation errors
x86: Add optimized popcnt variants
bitops: Optimize hweight() by making use of compile-time evaluation -
* 'x86-irq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, acpi/irq: Define gsi_end when X86_IO_APIC is undefined
x86, irq: Kill io_apic_renumber_irq
x86, acpi/irq: Handle isa irqs that are not identity mapped to gsi's.
x86, ioapic: Simplify probe_nr_irqs_gsi.
x86, ioapic: Optimize pin_2_irq
x86, ioapic: Move nr_ioapic_registers calculation to mp_register_ioapic.
x86, ioapic: In mpparse use mp_register_ioapic
x86, ioapic: Teach mp_register_ioapic to compute a global gsi_end
x86, ioapic: Fix the types of gsi values
x86, ioapic: Fix io_apic_redir_entries to return the number of entries.
x86, ioapic: Only export mp_find_ioapic and mp_find_ioapic_pin in io_apic.h
x86, acpi/irq: Generalize mp_config_acpi_legacy_irqs
x86, acpi/irq: Fix acpi_sci_ioapic_setup so it has both bus_irq and gsi
x86, acpi/irq: pci device dev->irq is an isa irq not a gsi
x86, acpi/irq: Teach acpi_get_override_irq to take a gsi not an isa_irq
x86, acpi/irq: Introduce apci_isa_irq_to_gsi
18 May, 2010
11 commits
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* 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, hypervisor: add missing
Modify the VMware balloon driver for the new x86_hyper API
x86, hypervisor: Export the x86_hyper* symbols
x86: Clean up the hypervisor layer
x86, HyperV: fix up the license to mshyperv.c
x86: Detect running on a Microsoft HyperV system
x86, cpu: Make APERF/MPERF a normal table-driven flag
x86, k8: Fix build error when K8_NB is disabled
x86, cacheinfo: Disable index in all four subcaches
x86, cacheinfo: Make L3 cache info per node
x86, cacheinfo: Reorganize AMD L3 cache structure
x86, cacheinfo: Turn off L3 cache index disable feature in virtualized environments
x86, cacheinfo: Unify AMD L3 cache index disable checking
cpufreq: Unify sysfs attribute definition macros
powernow-k8: Fix frequency reporting
x86, cpufreq: Add APERF/MPERF support for AMD processors
x86: Unify APERF/MPERF support
powernow-k8: Add core performance boost support
x86, cpu: Add AMD core boosting feature flag to /proc/cpuinfoFix up trivial conflicts in arch/x86/kernel/cpu/intel_cacheinfo.c and
drivers/cpufreq/cpufreq_ondemand.c -
…el/git/tip/linux-2.6-tip
* 'tracing-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
tracing: Fix "integer as NULL pointer" warning.
tracing: Fix tracepoint.h DECLARE_TRACE() to allow more than one header
tracing: Make the documentation clear on trace_event boot option
ring-buffer: Wrap open-coded WARN_ONCE
tracing: Convert nop macros to static inlines
tracing: Fix sleep time function profiling
tracing: Show sample std dev in function profiling
tracing: Add documentation for trace commands mod, traceon/traceoff
ring-buffer: Make benchmark handle missed events
ring-buffer: Make non-consuming read less expensive with lots of cpus.
tracing: Add graph output support for irqsoff tracer
tracing: Have graph flags passed in to ouput functions
tracing: Add ftrace events for graph tracer
tracing: Dump either the oops's cpu source or all cpus buffers
tracing: Fix uninitialized variable of tracing/trace output -
…/git/tip/linux-2.6-tip
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (49 commits)
stop_machine: Move local variable closer to the usage site in cpu_stop_cpu_callback()
sched, wait: Use wrapper functions
sched: Remove a stale comment
ondemand: Make the iowait-is-busy time a sysfs tunable
ondemand: Solve a big performance issue by counting IOWAIT time as busy
sched: Intoduce get_cpu_iowait_time_us()
sched: Eliminate the ts->idle_lastupdate field
sched: Fold updating of the last_update_time_info into update_ts_time_stats()
sched: Update the idle statistics in get_cpu_idle_time_us()
sched: Introduce a function to update the idle statistics
sched: Add a comment to get_cpu_idle_time_us()
cpu_stop: add dummy implementation for UP
sched: Remove rq argument to the tracepoints
rcu: need barrier() in UP synchronize_sched_expedited()
sched: correctly place paranioa memory barriers in synchronize_sched_expedited()
sched: kill paranoia check in synchronize_sched_expedited()
sched: replace migration_thread with cpu_stop
stop_machine: reimplement using cpu_stop
cpu_stop: implement stop_cpu[s]()
sched: Fix select_idle_sibling() logic in select_task_rq_fair()
... -
…git/tip/linux-2.6-tip
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (311 commits)
perf tools: Add mode to build without newt support
perf symbols: symbol inconsistency message should be done only at verbose=1
perf tui: Add explicit -lslang option
perf options: Type check all the remaining OPT_ variants
perf options: Type check OPT_BOOLEAN and fix the offenders
perf options: Check v type in OPT_U?INTEGER
perf options: Introduce OPT_UINTEGER
perf tui: Add workaround for slang < 2.1.4
perf record: Fix bug mismatch with -c option definition
perf options: Introduce OPT_U64
perf tui: Add help window to show key associations
perf tui: Make <- exit menus too
perf newt: Add single key shortcuts for zoom into DSO and threads
perf newt: Exit browser unconditionally when CTRL+C, q or Q is pressed
perf newt: Fix the 'A'/'a' shortcut for annotate
perf newt: Make <- exit the ui_browser
x86, perf: P4 PMU - fix counters management logic
perf newt: Make <- zoom out filters
perf report: Report number of events, not samples
perf hist: Clarify events_stats fields usage
...Fix up trivial conflicts in kernel/fork.c and tools/perf/builtin-record.c
-
* 'oprofile-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (24 commits)
oprofile/x86: make AMD IBS hotplug capable
oprofile/x86: notify cpus only when daemon is running
oprofile/x86: reordering some functions
oprofile/x86: stop disabled counters in nmi handler
oprofile/x86: protect cpu hotplug sections
oprofile/x86: remove CONFIG_SMP macros
oprofile/x86: fix uninitialized counter usage during cpu hotplug
oprofile/x86: remove duplicate IBS capability check
oprofile/x86: move IBS code
oprofile/x86: return -EBUSY if counters are already reserved
oprofile/x86: moving shutdown functions
oprofile/x86: reserve counter msrs pairwise
oprofile/x86: rework error handler in nmi_setup()
oprofile: update file list in MAINTAINERS file
oprofile: protect from not being in an IRQ context
oprofile: remove double ring buffering
ring-buffer: Add lost event count to end of sub buffer
tracing: Show the lost events in the trace_pipe output
ring-buffer: Add place holder recording of dropped events
tracing: Fix compile error in module tracepoints when MODULE_UNLOAD not set
... -
* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (24 commits)
rcu: remove all rcu head initializations, except on_stack initializations
rcu head introduce rcu head init on stack
Debugobjects transition check
rcu: fix build bug in RCU_FAST_NO_HZ builds
rcu: RCU_FAST_NO_HZ must check RCU dyntick state
rcu: make SRCU usable in modules
rcu: improve the RCU CPU-stall warning documentation
rcu: reduce the number of spurious RCU_SOFTIRQ invocations
rcu: permit discontiguous cpu_possible_mask CPU numbering
rcu: improve RCU CPU stall-warning messages
rcu: print boot-time console messages if RCU configs out of ordinary
rcu: disable CPU stall warnings upon panic
rcu: enable CPU_STALL_VERBOSE by default
rcu: slim down rcutiny by removing rcu_scheduler_active and friends
rcu: refactor RCU's context-switch handling
rcu: rename rcutiny rcu_ctrlblk to rcu_sched_ctrlblk
rcu: shrink rcutiny by making synchronize_rcu_bh() be inline
rcu: fix now-bogus rcu_scheduler_active comments.
rcu: Fix bogus CONFIG_PROVE_LOCKING in comments to reflect reality.
rcu: ignore offline CPUs in last non-dyntick-idle CPU check
... -
…/git/tip/linux-2.6-tip
* 'core-iommu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86/amd-iommu: Add amd_iommu=off command line option
iommu-api: Remove iommu_{un}map_range functions
x86/amd-iommu: Implement ->{un}map callbacks for iommu-api
x86/amd-iommu: Make amd_iommu_iova_to_phys aware of multiple page sizes
x86/amd-iommu: Make iommu_unmap_page and fetch_pte aware of page sizes
x86/amd-iommu: Make iommu_map_page and alloc_pte aware of page sizes
kvm: Change kvm_iommu_map_pages to map large pages
VT-d: Change {un}map_range functions to implement {un}map interface
iommu-api: Add ->{un}map callbacks to iommu_ops
iommu-api: Add iommu_map and iommu_unmap functions
iommu-api: Rename ->{un}map function pointers to ->{un}map_range -
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k:
m68k: amiga - Floppy platform device conversion
m68k: amiga - Sound platform device conversion
m68k: amiga - Frame buffer platform device conversion
m68k: amiga - Zorro host bridge platform device conversion
m68k: amiga - Zorro bus modalias support
platform: Make platform resource input parameters const
m68k: invoke oom-killer from page fault
serial167: Kill unused variables
m68k: Implement generic_find_next_{zero_,}le_bit()
m68k: hp300 - Checkpatch cleanup
m68k: Remove trailing spaces in messages
m68k: Simplify param.h by using
m68k: Remove BKL from rtc implementations -
Signed-off-by: Geert Uytterhoeven
-
Add Amiga Zorro bus modalias and uevent support
Signed-off-by: Geert Uytterhoeven
-
Make the platform resource input parameters of platform_device_add_resources()
and platform_device_register_simple() const, as the resources are copied and
never modified.Signed-off-by: Geert Uytterhoeven
Acked-by: Greg Kroah-Hartman
17 May, 2010
3 commits
-
When looking at a performance problem on PowerPC, I noticed some awful code
generation:c00000000051fc98: 3b 60 00 01 li r27,1
...
c00000000051fca0: 3b 80 00 00 li r28,0
...
c00000000051fcdc: 93 61 00 70 stw r27,112(r1)
c00000000051fce0: 93 81 00 74 stw r28,116(r1)
c00000000051fce4: 81 21 00 70 lwz r9,112(r1)
c00000000051fce8: 80 01 00 74 lwz r0,116(r1)
c00000000051fcec: 7d 29 07 b4 extsw r9,r9
c00000000051fcf0: 7c 00 07 b4 extsw r0,r0c00000000051fcf4: 7c 20 04 ac lwsync
c00000000051fcf8: 7d 60 f8 28 lwarx r11,0,r31
c00000000051fcfc: 7c 0b 48 00 cmpw r11,r9
c00000000051fd00: 40 c2 00 10 bne- c00000000051fd10
c00000000051fd04: 7c 00 f9 2d stwcx. r0,0,r31
c00000000051fd08: 40 c2 ff f0 bne+ c00000000051fcf8
c00000000051fd0c: 4c 00 01 2c isyncWe create two constants, write them out to the stack, read them straight back
in and sign extend them. What a mess.It turns out this bad code is a result of us defining atomic_t as a
volatile int.We removed the volatile attribute from the powerpc atomic_t definition years
ago, but commit ea435467500612636f8f4fb639ff6e76b2496e4b (atomic_t: unify all
arch definitions) added it back in.To dig up an old quote from Linus:
> The fact is, volatile on data structures is a bug. It's a wart in the C
> language. It shouldn't be used.
>
> Volatile accesses in *code* can be ok, and if we have "atomic_read()"
> expand to a "*(volatile int *)&(x)->value", then I'd be ok with that.
>
> But marking data structures volatile just makes the compiler screw up
> totally, and makes code for initialization sequences etc much worse.And screw up it does :)
With the volatile removed, we see much more reasonable code generation:
c00000000051f5b8: 3b 60 00 01 li r27,1
...
c00000000051f5c0: 3b 80 00 00 li r28,0
...c00000000051fc7c: 7c 20 04 ac lwsync
c00000000051fc80: 7c 00 f8 28 lwarx r0,0,r31
c00000000051fc84: 7c 00 d8 00 cmpw r0,r27
c00000000051fc88: 40 c2 00 10 bne- c00000000051fc98
c00000000051fc8c: 7f 80 f9 2d stwcx. r28,0,r31
c00000000051fc90: 40 c2 ff f0 bne+ c00000000051fc80
c00000000051fc94: 4c 00 01 2c isyncSix instructions less.
Signed-off-by: Anton Blanchard
Signed-off-by: Linus Torvalds -
In preparation for removing volatile from the atomic_t definition, this
patch adds a volatile cast to all the atomic read functions.Signed-off-by: Anton Blanchard
Signed-off-by: Linus Torvalds -
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6:
rtnetlink: make SR-IOV VF interface symmetric
sctp: delete active ICMP proto unreachable timer when free transport
tcp: fix MD5 (RFC2385) support
16 May, 2010
2 commits
-
Now we have a set of nested attributes:
IFLA_VFINFO_LIST (NESTED)
IFLA_VF_INFO (NESTED)
IFLA_VF_MAC
IFLA_VF_VLAN
IFLA_VF_TX_RATEThis allows a single set to operate on multiple attributes if desired.
Among other things, it means a dump can be replayed to set state.The current interface has yet to be released, so this seems like
something to consider for 2.6.34.Signed-off-by: Chris Wright
Signed-off-by: David S. Miller -
TCP MD5 support uses percpu data for temporary storage. It currently
disables preemption so that same storage cannot be reclaimed by another
thread on same cpu.We also have to make sure a softirq handler wont try to use also same
context. Various bug reports demonstrated corruptions.Fix is to disable preemption and BH.
Reported-by: Bhaskar Dutta
Signed-off-by: Eric Dumazet
Signed-off-by: David S. Miller
15 May, 2010
1 commit
-
1) i_flags simply doesn't work for mount/unlink race prevention;
we may have many links to file and rm on one of those obviously
shouldn't prevent bind on top of another later on. To fix it
right way we need to mark _dentry_ as unsuitable for mounting
upon; new flag (DCACHE_CANT_MOUNT) is protected by d_flags and
i_mutex on the inode in question. Set it (with dont_mount(dentry))
in unlink/rmdir/etc., check (with cant_mount(dentry)) in places
in namespace.c that used to check for S_DEAD. Setting S_DEAD
is still needed in places where we used to set it (for directories
getting killed), since we rely on it for readdir/rmdir race
prevention.2) rename()/mount() protection has another bogosity - we unhash
the target before we'd checked that it's not a mountpoint. Fixed.3) ancient bogosity in pivot_root() - we locked i_mutex on the
right directory, but checked S_DEAD on the different (and wrong)
one. Noticed and fixed.Signed-off-by: Al Viro
13 May, 2010
1 commit
-
Merge reason: Update from -rc5 to -rc7.
Signed-off-by: Ingo Molnar
12 May, 2010
4 commits
-
Originally, commit d899bf7b ("procfs: provide stack information for
threads") attempted to introduce a new feature for showing where the
threadstack was located and how many pages are being utilized by the
stack.Commit c44972f1 ("procfs: disable per-task stack usage on NOMMU") was
applied to fix the NO_MMU case.Commit 89240ba0 ("x86, fs: Fix x86 procfs stack information for threads on
64-bit") was applied to fix a bug in ia32 executables being loaded.Commit 9ebd4eba7 ("procfs: fix /proc//stat stack pointer for kernel
threads") was applied to fix a bug which had kernel threads printing a
userland stack address.Commit 1306d603f ('proc: partially revert "procfs: provide stack
information for threads"') was then applied to revert the stack pages
being used to solve a significant performance regression.This patch nearly undoes the effect of all these patches.
The reason for reverting these is it provides an unusable value in
field 28. For x86_64, a fork will result in the task->stack_start
value being updated to the current user top of stack and not the stack
start address. This unpredictability of the stack_start value makes
it worthless. That includes the intended use of showing how much stack
space a thread has.Other architectures will get different values. As an example, ia64
gets 0. The do_fork() and copy_process() functions appear to treat the
stack_start and stack_size parameters as architecture specific.I only partially reverted c44972f1 ("procfs: disable per-task stack usage
on NOMMU") . If I had completely reverted it, I would have had to change
mm/Makefile only build pagewalk.o when CONFIG_PROC_PAGE_MONITOR is
configured. Since I could not test the builds without significant effort,
I decided to not change mm/Makefile.I only partially reverted 89240ba0 ("x86, fs: Fix x86 procfs stack
information for threads on 64-bit") . I left the KSTK_ESP() change in
place as that seemed worthwhile.Signed-off-by: Robin Holt
Cc: Stefani Seibold
Cc: KOSAKI Motohiro
Cc: Michal Simek
Cc: Ingo Molnar
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
dma_sync_single_range_for_cpu() and dma_sync_single_range_for_device() use
a wrong address with a partial synchronization.Signed-off-by: FUJITA Tomonori
Reviewed-by: Konrad Rzeszutek Wilk
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Remove all rcu head inits. We don't care about the RCU head state before passing
it to call_rcu() anyway. Only leave the "on_stack" variants so debugobjects can
keep track of objects on stack.Signed-off-by: Mathieu Desnoyers
Signed-off-by: Paul E. McKenney -
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6:
net: Fix FDDI and TR config checks in ipv4 arp and LLC.
IPv4: unresolved multicast route cleanup
mac80211: remove association work when processing deauth request
ar9170: wait for asynchronous firmware loading
ipv4: udp: fix short packet and bad checksum logging
phy: Fix initialization in micrel driver.
sctp: Fix a race between ICMP protocol unreachable and connect()
veth: Dont kfree_skb() after dev_forward_skb()
IPv6: fix IPV6_RECVERR handling of locally-generated errors
net/gianfar: drop recycled skbs on MTU change
iwlwifi: work around passive scan issue
11 May, 2010
5 commits
-
epoll should not touch flags in wait_queue_t. This patch introduces a new
function __add_wait_queue_exclusive(), for the users, who use wait queue as a
LIFO queue.__add_wait_queue_tail_exclusive() is introduced too instead of
add_wait_queue_exclusive_locked(). remove_wait_queue_locked() is removed, as
it is a duplicate of __remove_wait_queue(), disliked by users, and with less
users.Signed-off-by: Changli Gao
Signed-off-by: Peter Zijlstra
Cc: Alexander Viro
Cc: Paul Menage
Cc: Li Zefan
Cc: Davide Libenzi
Cc:
LKML-Reference:
Signed-off-by: Ingo Molnar -
Conflicts:
arch/x86/kernel/amd_iommu.c -
This reverts commit 4fd38e4595e2f6c9d27732c042a0e16b2753049c.
It causes various crashes and hangs when events are activated.
The cause is not fully understood yet but we need to revert it
because the effects are severe.Reported-by: Stephane Eranian
Reported-by: Lin Ming
Cc: Peter Zijlstra
Cc: Corey Ashford
Cc: Mike Galbraith
Cc: Paul Mackerras
Cc: Arnaldo Carvalho de Melo
Cc: Frederic Weisbecker
LKML-Reference:
Signed-off-by: Ingo Molnar -
PEM:
o Would it be possible to make this bisectable as follows?a. Insert a new patch after current patch 4/6 that
defines destroy_rcu_head_on_stack(),
init_rcu_head_on_stack(), and init_rcu_head() with
their !CONFIG_DEBUG_OBJECTS_RCU_HEAD definitions.This patch performs this transition.
Signed-off-by: Mathieu Desnoyers
CC: "Paul E. McKenney"
CC: David S. Miller
CC: akpm@linux-foundation.org
CC: mingo@elte.hu
CC: laijs@cn.fujitsu.com
CC: dipankar@in.ibm.com
CC: josh@joshtriplett.org
CC: dvhltc@us.ibm.com
CC: niv@us.ibm.com
CC: tglx@linutronix.de
CC: peterz@infradead.org
CC: rostedt@goodmis.org
CC: Valdis.Kletnieks@vt.edu
CC: dhowells@redhat.com
CC: eric.dumazet@gmail.com
CC: Alexey Dobriyan
Signed-off-by: Paul E. McKenney -
Implement a basic state machine checker in the debugobjects.
This state machine checker detects races and inconsistencies within the "active"
life of a debugobject. The checker only keeps track of the current state; all
the state machine logic is kept at the object instance level.The checker works by adding a supplementary "unsigned int astate" field to the
debug_obj structure. It keeps track of the current "active state" of the object.The only constraints that are imposed on the states by the debugobjects system
is that:- activation of an object sets the current active state to 0,
- deactivation of an object expects the current active state to be 0.For the rest of the states, the state mapping is determined by the specific
object instance. Therefore, the logic keeping track of the state machine is
within the specialized instance, without any need to know about it at the
debugobject level.The current object active state is changed by calling:
debug_object_active_state(addr, descr, expect, next)
where "expect" is the expected state and "next" is the next state to move to if
the expected state is found. A warning is generated if the expected is not
found.Signed-off-by: Mathieu Desnoyers
Reviewed-by: Thomas Gleixner
Acked-by: David S. Miller
CC: "Paul E. McKenney"
CC: akpm@linux-foundation.org
CC: mingo@elte.hu
CC: laijs@cn.fujitsu.com
CC: dipankar@in.ibm.com
CC: josh@joshtriplett.org
CC: dvhltc@us.ibm.com
CC: niv@us.ibm.com
CC: peterz@infradead.org
CC: rostedt@goodmis.org
CC: Valdis.Kletnieks@vt.edu
CC: dhowells@redhat.com
CC: eric.dumazet@gmail.com
CC: Alexey Dobriyan
Signed-off-by: Paul E. McKenney
