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Add a test which shows a race in the multi-order iteration code. This
test reliably hits the race in under a second on my machine, and is the
result of a real bug report against kernel a production v4.15 based
kernel (4.15.6-300.fc27.x86_64). With a real kernel this issue is hit
when using order 9 PMD DAX radix tree entries.
The race has to do with how we tear down multi-order sibling entries
when we are removing an item from the tree. Remember that an order 2
entry looks like this:
struct radix_tree_node.slots[] = [entry][sibling][sibling][sibling]
where 'entry' is in some slot in the struct radix_tree_node, and the
three slots following 'entry' contain sibling pointers which point back
to 'entry.'
When we delete 'entry' from the tree, we call :
radix_tree_delete()
radix_tree_delete_item()
__radix_tree_delete()
replace_slot()
replace_slot() first removes the siblings in order from the first to the
last, then at then replaces 'entry' with NULL. This means that for a
brief period of time we end up with one or more of the siblings removed,
so:
struct radix_tree_node.slots[] = [entry][NULL][sibling][sibling]
This causes an issue if you have a reader iterating over the slots in
the tree via radix_tree_for_each_slot() while only under
rcu_read_lock()/rcu_read_unlock() protection. This is a common case in
mm/filemap.c.
The issue is that when __radix_tree_next_slot() => skip_siblings() tries
to skip over the sibling entries in the slots, it currently does so with
an exact match on the slot directly preceding our current slot.
Normally this works:
V preceding slot
struct radix_tree_node.slots[] = [entry][sibling][sibling][sibling]
^ current slot
This lets you find the first sibling, and you skip them all in order.
But in the case where one of the siblings is NULL, that slot is skipped
and then our sibling detection is interrupted:
V preceding slot
struct radix_tree_node.slots[] = [entry][NULL][sibling][sibling]
^ current slot
This means that the sibling pointers aren't recognized since they point
all the way back to 'entry', so we think that they are normal internal
radix tree pointers. This causes us to think we need to walk down to a
struct radix_tree_node starting at the address of 'entry'.
In a real running kernel this will crash the thread with a GP fault when
you try and dereference the slots in your broken node starting at
'entry'.
In the radix tree test suite this will be caught by the address
sanitizer:
==27063==ERROR: AddressSanitizer: heap-buffer-overflow on address
0x60c0008ae400 at pc 0x00000040ce4f bp 0x7fa89b8fcad0 sp 0x7fa89b8fcac0
READ of size 8 at 0x60c0008ae400 thread T3
#0 0x40ce4e in __radix_tree_next_slot /home/rzwisler/project/linux/tools/testing/radix-tree/radix-tree.c:1660
#1 0x4022cc in radix_tree_next_slot linux/../../../../include/linux/radix-tree.h:567
#2 0x4022cc in iterator_func /home/rzwisler/project/linux/tools/testing/radix-tree/multiorder.c:655
#3 0x7fa8a088d50a in start_thread (/lib64/libpthread.so.0+0x750a)
#4 0x7fa8a03bd16e in clone (/lib64/libc.so.6+0xf516e)
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ross Zwisler <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: CR, Sapthagirish <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Dave Chinner <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Currently the lifetime of "struct item" entries in the radix tree are
not controlled by RCU, but are instead deleted inline as they are
removed from the tree.
In the following patches we add a test which has threads iterating over
items pulled from the tree and verifying them in an
rcu_read_lock()/rcu_read_unlock() section. This means that though an
item has been removed from the tree it could still be being worked on by
other threads until the RCU grace period expires. So, we need to
actually free the "struct item" structures at the end of the grace
period, just as we do with "struct radix_tree_node" items.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ross Zwisler <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: CR, Sapthagirish <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Dave Chinner <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Pulled from a patch from Matthew Wilcox entitled "xarray: Add definition
of struct xarray":
> From: Matthew Wilcox <[email protected]>
> Signed-off-by: Matthew Wilcox <[email protected]>
https://patchwork.kernel.org/patch/10341249/
These defines fix this compilation error:
In file included from ./linux/radix-tree.h:6:0,
from ./linux/../../../../include/linux/idr.h:15,
from ./linux/idr.h:1,
from idr.c:4:
./linux/../../../../include/linux/idr.h: In function `idr_init_base':
./linux/../../../../include/linux/radix-tree.h:129:2: warning: implicit declaration of function `spin_lock_init'; did you mean `spinlock_t'? [-Wimplicit-function-declaration]
spin_lock_init(&(root)->xa_lock); \
^
./linux/../../../../include/linux/idr.h:126:2: note: in expansion of macro `INIT_RADIX_TREE'
INIT_RADIX_TREE(&idr->idr_rt, IDR_RT_MARKER);
^~~~~~~~~~~~~~~
by providing a spin_lock_init() wrapper for the v4.17-rc* version of the
radix tree test suite.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ross Zwisler <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: CR, Sapthagirish <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Dave Chinner <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Commit c6ce3e2fe3da ("radix tree test suite: Add config option for map
shift") introduced a phony makefile target called 'mapshift' that ends
up generating the file generated/map-shift.h. This phony target was
then added as a dependency of the top level 'targets' build target,
which is what is run when you go to tools/testing/radix-tree and just
type 'make'.
Unfortunately, this phony target doesn't actually work as a dependency,
so you end up getting:
$ make
make: *** No rule to make target 'generated/map-shift.h', needed by 'main.o'. Stop.
make: *** Waiting for unfinished jobs....
Fix this by making the file generated/map-shift.h our real makefile
target, and add this a dependency of the top level build target.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ross Zwisler <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: CR, Sapthagirish <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Dave Chinner <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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When running bpf's selftest test_xdp_meta.sh it fails:
./test_xdp_meta.sh
Error: Specified qdisc not found.
selftests: test_xdp_meta [FAILED]
Need to enable CONFIG_NET_SCH_INGRESS and CONFIG_NET_CLS_ACT to get the
test to pass.
Fixes: 22c8852624fc ("bpf: improve selftests and add tests for meta pointer")
Signed-off-by: Anders Roxell <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
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Currently perf has a feature to account cycles for LBRs
For example, on skylake:
perf record -b ...
perf report or perf annotate
And then browsing the annotate browser gives average cycle counts for
program blocks.
For some analysis it would be useful if we could know not only the
average cycles but also the min and max cycles.
This patch records the min and max cycles.
Signed-off-by: Jin Yao <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Kan Liang <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
[ Switch from max/min to min/max ]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
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Since the ip shown for a symbol is now always a virtual address, it
becomes difficult to correlate this with objdump output and determine
the exact instruction address. So, we always show the offset from the
start of the symbol.
This can be verified on a powerpc64le system running Fedora 27 as
follows:
# perf probe -a sys_write
# perf record -e probe:sys_write -g ~/test
Before applying this patch:
# perf script
test 9710 [013] 95614.332431: probe:sys_write: (c0000000004025b0)
c0000000004025b0 sys_write (/lib/modules/4.17.0-rc4+/build/vmlinux)
c00000000000b9e0 system_call (/lib/modules/4.17.0-rc4+/build/vmlinux)
7fffb70d8234 __GI___libc_write (/usr/lib64/libc-2.26.so)
7fffb7052c74 _IO_file_write@@GLIBC_2.17 (/usr/lib64/libc-2.26.so)
5afc1818 [unknown] ([unknown])
7fffb7051a60 new_do_write (/usr/lib64/libc-2.26.so)
7fffb7054638 _IO_do_write@@GLIBC_2.17 (/usr/lib64/libc-2.26.so)
7fffb7054bbc _IO_file_overflow@@GLIBC_2.17 (/usr/lib64/libc-2.26.so)
7fffb7055a24 __overflow (/usr/lib64/libc-2.26.so)
7fffb7044548 _IO_puts (/usr/lib64/libc-2.26.so)
10000440 main (/home/sandipan/test)
7fffb6fe36a0 generic_start_main.isra.0 (/usr/lib64/libc-2.26.so)
7fffb6fe3898 __libc_start_main (/usr/lib64/libc-2.26.so)
0 [unknown] ([unknown])
...
After applying this patch:
# perf script
test 9710 [013] 95614.332431: probe:sys_write: (c0000000004025b0)
c0000000004025b0 sys_write+0x10 (/lib/modules/4.17.0-rc4+/build/vmlinux)
c00000000000b9e0 system_call+0x58 (/lib/modules/4.17.0-rc4+/build/vmlinux)
7fffb70d8234 __GI___libc_write+0x24 (/usr/lib64/libc-2.26.so)
7fffb7052c74 _IO_file_write@@GLIBC_2.17+0x44 (/usr/lib64/libc-2.26.so)
5afc1818 [unknown] ([unknown])
7fffb7051a60 new_do_write+0x90 (/usr/lib64/libc-2.26.so)
7fffb7054638 _IO_do_write@@GLIBC_2.17+0x38 (/usr/lib64/libc-2.26.so)
7fffb7054bbc _IO_file_overflow@@GLIBC_2.17+0x14c (/usr/lib64/libc-2.26.so)
7fffb7055a24 __overflow+0x64 (/usr/lib64/libc-2.26.so)
7fffb7044548 _IO_puts+0x218 (/usr/lib64/libc-2.26.so)
10000440 main+0x20 (/home/sandipan/test)
7fffb6fe36a0 generic_start_main.isra.0+0x140 (/usr/lib64/libc-2.26.so)
7fffb6fe3898 __libc_start_main+0xb8 (/usr/lib64/libc-2.26.so)
0 [unknown] ([unknown])
...
Signed-off-by: Sandipan Das <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Naveen N. Rao <[email protected]>
Cc: Ravi Bangoria <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
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Commit 0a6748740368 ("selftests/bpf: Only run tests if !bpf_disabled")
forgot to check return value of fopen.
This caused some confusion, when running test_verifier (from
tools/testing/selftests/bpf/) on an older kernel (< v4.4) as it will
simply seqfault.
This fix avoids the segfault and prints an error, but allow program to
continue. Given the sysctl was introduced in 1be7f75d1668 ("bpf:
enable non-root eBPF programs"), we know that the running kernel
cannot support unpriv, thus continue with unpriv_disabled = true.
Fixes: 0a6748740368 ("selftests/bpf: Only run tests if !bpf_disabled")
Signed-off-by: Jesper Dangaard Brouer <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
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When perf data is recorded with the call-graph option enabled, the
callchain shown by perf script shows the binary offsets of the symbols
as the ip. This is incorrect for kernel symbols as the ip values are
always off by a fixed offset depending on the architecture. If the
offsets from the start of the symbols are printed, they are also
incorrect for both kernel and userspace symbols.
Without the call-graph option, the callchain shows the virtual addresses
of the symbols rather than their binary offsets. The offsets printed in
this case are also correct.
This fixes the inconsistency in perf script's output.
This can be verified on a powerpc64le system running Fedora 27 as
follows:
# cat /proc/kallsyms | grep sys_write
...
c0000000004025a0 T sys_write
c0000000004025a0 T __se_sys_write
...
# perf probe -a sys_write
Before applying this patch:
# perf record -e probe:sys_write -g ~/test
# perf script -F ip,sym,symoff
4125b0 sys_write+0x8000000000008010
1b9e0 system_call+0x8000000000008058
118234 __GI___libc_write+0xffff0000f52c0024
92c74 _IO_file_write@@GLIBC_2.17+0xffff0000f52c0044
5afbfd8a [unknown]
91a60 new_do_write+0xffff0000f52c0090
94638 _IO_do_write@@GLIBC_2.17+0xffff0000f52c0038
94bbc _IO_file_overflow@@GLIBC_2.17+0xffff0000f52c014c
95a24 __overflow+0xffff0000f52c0064
84548 _IO_puts+0xffff0000f52c0218
440 main+0xffffffffe0000020
236a0 generic_start_main.isra.0+0xffff0000f52c0140
23898 __libc_start_main+0xffff0000f52c00b8
0 [unknown]
...
# perf record -e probe:sys_write ~/test
# perf script -F ip,sym,symoff
c0000000004025b0 sys_write+0x10
...
After applying this patch:
# perf record -e probe:sys_write -g ~/test
# perf script -F ip,sym,symoff
c0000000004025b0 sys_write+0x10
c00000000000b9e0 system_call+0x58
7fffb70d8234 __GI___libc_write+0x24
7fffb7052c74 _IO_file_write@@GLIBC_2.17+0x44
5afc1818 [unknown]
7fffb7051a60 new_do_write+0x90
7fffb7054638 _IO_do_write@@GLIBC_2.17+0x38
7fffb7054bbc _IO_file_overflow@@GLIBC_2.17+0x14c
7fffb7055a24 __overflow+0x64
7fffb7044548 _IO_puts+0x218
10000440 main+0x20
7fffb6fe36a0 generic_start_main.isra.0+0x140
7fffb6fe3898 __libc_start_main+0xb8
0 [unknown]
...
# perf record -e probe:sys_write ~/test
# perf script -F ip,sym,symoff
c0000000004025b0 sys_write+0x10
...
Signed-off-by: Sandipan Das <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Naveen N. Rao <[email protected]>
Cc: Ravi Bangoria <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
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Let tools that need to have those variables with the sysctl current
values use a function that will read them.
Cc: Adrian Hunter <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Wang Nan <[email protected]>
Link: https://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
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It is not read as commonly as 'page_size', so it makes sense to read it
lazily, caching its value when it is first read.
Less files open unconditionally at startup.
Cc: Adrian Hunter <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Wang Nan <[email protected]>
Link: https://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
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Adopt it from the kernel sources, will be used soon.
Cc: Adrian Hunter <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Wang Nan <[email protected]>
Link: https://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
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Not anymore accessed outside this library, keep it private.
Cc: Adrian Hunter <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Wang Nan <[email protected]>
Link: https://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
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That takes care of using the right call to get the tracing_path
directory, the one that will end up calling tracing_path_set() to figure
out where tracefs is mounted.
One more step in doing just lazy reading of system structures to reduce
the number of operations done unconditionaly at 'perf' start.
Cc: Adrian Hunter <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Wang Nan <[email protected]>
Link: https://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
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Instead of accessing the trace_events_path variable directly, that may
not have been properly initialized wrt detecting where tracefs is
mounted.
Cc: Adrian Hunter <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Wang Nan <[email protected]>
Link: https://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
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When using for_each_event() we needlessly rebuild the whole path to
the tracepoint directory, reuse the dir_path instead, saving some cycles
and reducing the size of the next patch.
Cc: Adrian Hunter <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Wang Nan <[email protected]>
Link: https://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
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Pull kvm fixes from Paolo Bonzini:
- ARM/ARM64 locking fixes
- x86 fixes: PCID, UMIP, locking
- improved support for recent Windows version that have a 2048 Hz APIC
timer
- rename KVM_HINTS_DEDICATED CPUID bit to KVM_HINTS_REALTIME
- better behaved selftests
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
kvm: rename KVM_HINTS_DEDICATED to KVM_HINTS_REALTIME
KVM: arm/arm64: VGIC/ITS save/restore: protect kvm_read_guest() calls
KVM: arm/arm64: VGIC/ITS: protect kvm_read_guest() calls with SRCU lock
KVM: arm/arm64: VGIC/ITS: Promote irq_lock() in update_affinity
KVM: arm/arm64: Properly protect VGIC locks from IRQs
KVM: X86: Lower the default timer frequency limit to 200us
KVM: vmx: update sec exec controls for UMIP iff emulating UMIP
kvm: x86: Suppress CR3_PCID_INVD bit only when PCIDs are enabled
KVM: selftests: exit with 0 status code when tests cannot be run
KVM: hyperv: idr_find needs RCU protection
x86: Delay skip of emulated hypercall instruction
KVM: Extend MAX_IRQ_ROUTES to 4096 for all archs
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To make reading events files a tad more compact than with
get_tracing_files("events/foo").
Cc: Adrian Hunter <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Wang Nan <[email protected]>
Link: https://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
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memory allocation
Allow the user to override the default trace buffer memory allocation
by adding a command line option to override the default.
The patch also:
Adds a SIGINT (i.e. CTRL C exit) handler,
so that things can be cleaned up before exit.
Moves the postion of some other cleanup from after to
before the potential "No valid data to plot" exit.
Replaces all quit() calls with sys.exit, because
quit() is not supposed to be used in scripts.
Signed-off-by: Doug Smythies <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>
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One should use tracing_path_mount() instead, so more things get done
lazily instead of at every 'perf' tool call startup.
Cc: Adrian Hunter <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Wang Nan <[email protected]>
Link: https://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
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Its only used in the file it is defined, so just make it static.
Cc: Adrian Hunter <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Wang Nan <[email protected]>
Link: https://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
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We check what perf_config__init() does at each perf_config() call,
namely if the static perf_config instance was created, so instead of
bailing out in that case, try to allocate it, bailing if it fails.
Now to get the perf_config() call out of the start of perf's main()
function, doing it also lazily.
Cc: Adrian Hunter <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Taeung Song <[email protected]>
Cc: Wang Nan <[email protected]>
Link: https://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
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bpf_object__open()/bpf_object__open_buffer can return error pointer or
NULL, check the return values with IS_ERR_OR_NULL() in bpf__prepare_load
and bpf__prepare_load_buffer
Signed-off-by: YueHaibing <[email protected]>
Acked-by: Daniel Borkmann <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: [email protected]
Link: https://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
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Perf stat doesn't count the uncore event aliases from the same uncore
block in a group, for example:
perf stat -e '{unc_m_cas_count.all,unc_m_clockticks}' -a -I 1000
# time counts unit events
1.000447342 <not counted> unc_m_cas_count.all
1.000447342 <not counted> unc_m_clockticks
2.000740654 <not counted> unc_m_cas_count.all
2.000740654 <not counted> unc_m_clockticks
The output is very misleading. It gives a wrong impression that the
uncore event doesn't work.
An uncore block could be composed by several PMUs. An uncore event alias
is a joint name which means the same event runs on all PMUs of a block.
Perf doesn't support mixed events from different PMUs in the same group.
It is wrong to put uncore event aliases in a big group.
The right way is to split the big group into multiple small groups which
only include the events from the same PMU.
Only uncore event aliases from the same uncore block should be specially
handled here. It doesn't make sense to mix the uncore events with other
uncore events from different blocks or even core events in a group.
With the patch:
# time counts unit events
1.001557653 140,833 unc_m_cas_count.all
1.001557653 1,330,231,332 unc_m_clockticks
2.002709483 85,007 unc_m_cas_count.all
2.002709483 1,429,494,563 unc_m_clockticks
Reported-by: Andi Kleen <[email protected]>
Signed-off-by: Kan Liang <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Cc: Agustin Vega-Frias <[email protected]>
Cc: Ganapatrao Kulkarni <[email protected]>
Cc: Jin Yao <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Shaokun Zhang <[email protected]>
Cc: Will Deacon <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu
- Updates to the handling of expedited grace periods, perhaps most
notably parallelizing their initialization. Other changes
include fixes from Boqun Feng.
- Miscellaneous fixes. These include an nvme fix from Nitzan Carmi
that I am carrying because it depends on a new SRCU function
cleanup_srcu_struct_quiesced(). This branch also includes fixes
from Byungchul Park and Yury Norov.
- Updates to reduce lock contention in the rcu_node combining tree.
These are in preparation for the consolidation of RCU-bh,
RCU-preempt, and RCU-sched into a single flavor, which was
requested by Linus Torvalds in response to a security flaw
whose root cause included confusion between the multiple flavors
of RCU.
- Torture-test updates that save their users some time and effort.
Conflicts:
drivers/nvme/host/core.c
Signed-off-by: Ingo Molnar <[email protected]>
|
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Currently, kvm-find-errors.sh looks only for build errors ("error:"),
so this commit makes it also locate build warnings ("warning:").
Signed-off-by: Paul E. McKenney <[email protected]>
Tested-by: Nicholas Piggin <[email protected]>
|
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With the addition of the end-of-test state, it is not uncommon for the
kvm.sh summary lines to overflow 80 characters. This commit therefore
applies abbreviations in order to make the line fit into 80 characters
with high probability.
And yes, I did make heavy use of punched cards back in the day, so 80
columns it is for my xterms! ;-)
Signed-off-by: Paul E. McKenney <[email protected]>
Tested-by: Nicholas Piggin <[email protected]>
|
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This commit adds the end-of-test test, if present in the console output,
to the kvm.sh test summary that is printed by kvm-recheck.sh. Note that
this only applies to rcutorture console output.
Signed-off-by: Paul E. McKenney <[email protected]>
Tested-by: Nicholas Piggin <[email protected]>
|
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The rcutorture scripting scans the console output twice, once to look
for various sorts of hangs and again to find warnings and panics.
Unfortunately, only the output of the second scan gets written to the
console.log.diags file, which can cause hangs to be overlooked.
This commit therefore folds the parse-torture.sh script (which looks
for hangs) into the parse-console.sh script (which looks for warnings
and panics). This allows both types of failure information to be
added to console.log.diags, while still reliably removing this file
when it proves to be empty.
This also fixes a long-standing bug where rcuperf log files would
unconditionally complain about a hang.
Signed-off-by: Paul E. McKenney <[email protected]>
Tested-by: Nicholas Piggin <[email protected]>
|
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This commit adds a script that allows viewing the build and/or
console output from failed rcutorture, locktorture, or rcuperf runs.
This replaces a time-honored but inefficient manual procedure that uses
cut and paste.
Signed-off-by: Paul E. McKenney <[email protected]>
Tested-by: Nicholas Piggin <[email protected]>
|
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kcore
The first symbol is not necessarily in the kernel text. Instead of
using the first symbol, use the _stest symbol to identify the kernel map
when loading kcore.
This allows for the introduction of symbols to identify the x86_64 PTI
entry trampolines.
Signed-off-by: Adrian Hunter <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Joerg Roedel <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
|
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So that kprobe definitions become:
int probe(function, variables)(void *ctx, int err, var1, var2, ...)
The existing 5sec.c, got converted and goes from:
SEC("func=hrtimer_nanosleep rqtp->tv_sec")
int func(void *ctx, int err, long sec)
{
}
To:
int probe(hrtimer_nanosleep, rqtp->tv_sec)(void *ctx, int err, long sec)
{
}
If we decide to add tv_nsec as well, then it becomes:
$ cat tools/perf/examples/bpf/5sec.c
#include <bpf.h>
int probe(hrtimer_nanosleep, rqtp->tv_sec rqtp->tv_nsec)(void *ctx, int err, long sec, long nsec)
{
return sec == 5;
}
license(GPL);
$
And if we run it, system wide as before and run some 'sleep' with values
for the tv_nsec field, we get:
# perf trace --no-syscalls -e tools/perf/examples/bpf/5sec.c
0.000 perf_bpf_probe:hrtimer_nanosleep:(ffffffff9811b5f0) tv_sec=5 tv_nsec=100000000
9641.650 perf_bpf_probe:hrtimer_nanosleep:(ffffffff9811b5f0) tv_sec=5 tv_nsec=123450001
^C#
Cc: Adrian Hunter <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Wang Nan <[email protected]>
Link: https://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
|
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To further reduce boilerplate.
Cc: Adrian Hunter <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Wang Nan <[email protected]>
Link: https://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
|
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Description:
. Disable strace like syscall tracing (--no-syscalls), or try tracing
just some (-e *sleep).
. Attach a filter function to a kernel function, returning when it should
be considered, i.e. appear on the output:
$ cat tools/perf/examples/bpf/5sec.c
#include <bpf.h>
SEC("func=hrtimer_nanosleep rqtp->tv_sec")
int func(void *ctx, int err, long sec)
{
return sec == 5;
}
char _license[] SEC("license") = "GPL";
int _version SEC("version") = LINUX_VERSION_CODE;
$
. Run it system wide, so that any sleep of >= 5 seconds and < than 6
seconds gets caught.
. Ask for callgraphs using DWARF info, so that userspace can be unwound
. While this is running, run something like "sleep 5s".
# perf trace --no-syscalls -e tools/perf/examples/bpf/5sec.c/call-graph=dwarf/
0.000 perf_bpf_probe:func:(ffffffff9811b5f0) tv_sec=5
hrtimer_nanosleep ([kernel.kallsyms])
__x64_sys_nanosleep ([kernel.kallsyms])
do_syscall_64 ([kernel.kallsyms])
entry_SYSCALL_64 ([kernel.kallsyms])
__GI___nanosleep (/usr/lib64/libc-2.26.so)
rpl_nanosleep (/usr/bin/sleep)
xnanosleep (/usr/bin/sleep)
main (/usr/bin/sleep)
__libc_start_main (/usr/lib64/libc-2.26.so)
_start (/usr/bin/sleep)
^C#
Cc: Adrian Hunter <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Wang Nan <[email protected]>
Link: https://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
|
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So, the first helper is the one shortening a variable/function section
attribute, from, for instance:
char _license[] __attribute__((section("license"), used)) = "GPL";
to:
char _license[] SEC("license") = "GPL";
Convert empty.c to that and it becomes:
# cat ~acme/lib/examples/perf/bpf/empty.c
#include <bpf.h>
char _license[] SEC("license") = "GPL";
int _version SEC("version") = LINUX_VERSION_CODE;
#
Cc: Adrian Hunter <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Wang Nan <[email protected]>
Link: https://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
|
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The first one is the bare minimum that bpf infrastructure accepts before
it expects actual events to be set up:
$ cat tools/perf/examples/bpf/empty.c
char _license[] __attribute__((section("license"), used)) = "GPL";
int _version __attribute__((section("version"), used)) = LINUX_VERSION_CODE;
$
If you remove that "version" line, then it will be refused with:
# perf trace -e tools/perf/examples/bpf/empty.c
event syntax error: 'tools/perf/examples/bpf/empty.c'
\___ Failed to load tools/perf/examples/bpf/empty.c from source: 'version' section incorrect or lost
(add -v to see detail)
Run 'perf list' for a list of valid events
Usage: perf trace [<options>] [<command>]
or: perf trace [<options>] -- <command> [<options>]
or: perf trace record [<options>] [<command>]
or: perf trace record [<options>] -- <command> [<options>]
-e, --event <event> event/syscall selector. use 'perf list' to list available events
#
The next ones will, step by step, show simple filters, then the needs
for headers will be made clear, it will be put in place and tested with
new examples, rinse, repeat.
Back to using this first one to test the perf+bpf infrastructure:
If we run it will fail, as no functions are present connecting with,
say, a tracepoint or a function using the kprobes or uprobes
infrastructure:
# perf trace -e tools/perf/examples/bpf/empty.c
WARNING: event parser found nothing
invalid or unsupported event: 'tools/perf/examples/bpf/empty.c'
Run 'perf list' for a list of valid events
Usage: perf trace [<options>] [<command>]
or: perf trace [<options>] -- <command> [<options>]
or: perf trace record [<options>] [<command>]
or: perf trace record [<options>] -- <command> [<options>]
-e, --event <event> event/syscall selector. use 'perf list' to list available events
#
But, if we set things up to dump the generated object file to a file,
and do this after having run 'make install', still on the developer's
$HOME directory:
# cat ~/.perfconfig
[llvm]
dump-obj = true
#
# perf trace -e ~acme/lib/examples/perf/bpf/empty.c
LLVM: dumping /home/acme/lib/examples/perf/bpf/empty.o
WARNING: event parser found nothing
invalid or unsupported event: '/home/acme/lib/examples/perf/bpf/empty.c'
<SNIP>
#
We can look at the dumped object file:
# ls -la ~acme/lib/examples/perf/bpf/empty.o
-rw-r--r--. 1 root root 576 May 4 12:10 /home/acme/lib/examples/perf/bpf/empty.o
# file ~acme/lib/examples/perf/bpf/empty.o
/home/acme/lib/examples/perf/bpf/empty.o: ELF 64-bit LSB relocatable, *unknown arch 0xf7* version 1 (SYSV), not stripped
# readelf -sw ~acme/lib/examples/perf/bpf/empty.o
Symbol table '.symtab' contains 3 entries:
Num: Value Size Type Bind Vis Ndx Name
0: 0000000000000000 0 NOTYPE LOCAL DEFAULT UND
1: 0000000000000000 0 NOTYPE GLOBAL DEFAULT 3 _license
2: 0000000000000000 0 NOTYPE GLOBAL DEFAULT 4 _version
#
# tools/bpf/bpftool/bpftool --pretty ~acme/lib/examples/perf/bpf/empty.o
null
#
Cc: Adrian Hunter <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Wang Nan <[email protected]>
Link: https://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
|
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We'll start putting headers for helpers to be used in eBPF proggies in
there:
# perf trace -v --no-syscalls -e empty.c |& grep "llvm compiling command : "
llvm compiling command : /usr/lib64/ccache/clang -D__KERNEL__ -D__NR_CPUS__=4 -DLINUX_VERSION_CODE=0x41100 -nostdinc -isystem /usr/lib/gcc/x86_64-redhat-linux/7/include -I/home/acme/git/linux/arch/x86/include -I./arch/x86/include/generated -I/home/acme/git/linux/include -I./include -I/home/acme/git/linux/arch/x86/include/uapi -I./arch/x86/include/generated/uapi -I/home/acme/git/linux/include/uapi -I./include/generated/uapi -include /home/acme/git/linux/include/linux/kconfig.h -I/home/acme/lib/include/perf/bpf -Wno-unused-value -Wno-pointer-sign -working-directory /lib/modules/4.17.0-rc3-00034-gf4ef6a438cee/build -c /home/acme/bpf/empty.c -target bpf -O2 -o -
#
Notice the "-I/home/acme/lib/include/perf/bpf"
Cc: Adrian Hunter <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Wang Nan <[email protected]>
Link: https://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
|
|
Warn perf buildid-cache --purge-all failures in non verbose mode.
Ex.:
$ sudo chown root:root /home/ravi/.debug -R
$ sudo chmod 700 /home/ravi/.debug/ -R
$ ./perf buildid-cache -P
Couldn't remove some caches. Error: Permission denied.
Suggested-by: Masami Hiramatsu <[email protected]>
Signed-off-by: Ravi Bangoria <[email protected]>
Acked-by: Masami Hiramatsu <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
|
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To avoid regressions such as the one fixed by 4a35a9027f64 ("Revert
"perf pmu: Fix pmu events parsing rule""), where '-e intel_pt//u' got
broken, with this new entry in this 'perf tests' subtest, we would have
caught it before pushing upstream.
Acked-by: Jiri Olsa <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Kan Liang <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Wang Nan <[email protected]>
Link: https://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
|
|
To pick up fixes, notably the revert for the intel_pt//u regression.
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent
Pull perf/urgent fixes from Arnaldo Carvalho de Melo:
- Fix segfault when processing unknown threads in cs-etm (Leo Yan)
- Fix "perf test inet_pton" on s390 failing due to missing inline (Thomas Richter)
- Display all available events on 'perf annotate --stdio' (Jin Yao)
- Add missing newline when parsing empty BPF proggie (Arnaldo Carvalho de Melo)
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
|
|
The paper discusses the revised ARMv8 memory model; such revision
had an important impact on the design of the LKMM.
Signed-off-by: Andrea Parri <[email protected]>
Signed-off-by: Paul E. McKenney <[email protected]>
Cc: Akira Yokosawa <[email protected]>
Cc: Alan Stern <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Boqun Feng <[email protected]>
Cc: David Howells <[email protected]>
Cc: Jade Alglave <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Luc Maranget <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: [email protected]
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
|
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ASPLOS 2018 was held in March: make sure this is reflected in
header comments and references.
Signed-off-by: Andrea Parri <[email protected]>
Signed-off-by: Paul E. McKenney <[email protected]>
Cc: Akira Yokosawa <[email protected]>
Cc: Alan Stern <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Boqun Feng <[email protected]>
Cc: David Howells <[email protected]>
Cc: Jade Alglave <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Luc Maranget <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: [email protected]
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
|
|
This commit uses tabs for indentation and adds spaces around binary
operator.
Signed-off-by: Andrea Parri <[email protected]>
Signed-off-by: Paul E. McKenney <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
|
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lock.cat contains old comments and code referring to the possibility
of LKR events that are not part of an RMW pair. This is a holdover
from when I though we might end up using LKR events to implement
spin_is_locked(). Reword the comments to remove this assumption and
replace domain(lk-rmw) in the code with LKR.
Tested-by: Andrea Parri <[email protected]>
[ paulmck: Pulled as lock-nest into previous line as discussed. ]
Signed-off-by: Alan Stern <[email protected]>
Signed-off-by: Paul E. McKenney <[email protected]>
Cc: Akira Yokosawa <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Boqun Feng <[email protected]>
Cc: David Howells <[email protected]>
Cc: Jade Alglave <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Luc Maranget <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: [email protected]
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
|
|
The code in lock.cat which checks for normal read/write accesses to
spinlock variables doesn't take into account the newly added RL and RU
events. Add them into the test, and move the resulting code up near
the start of the file, since a violation would indicate a pretty
severe conceptual error in a litmus test.
Tested-by: Andrea Parri <[email protected]>
Signed-off-by: Alan Stern <[email protected]>
Signed-off-by: Paul E. McKenney <[email protected]>
Cc: Akira Yokosawa <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Boqun Feng <[email protected]>
Cc: David Howells <[email protected]>
Cc: Jade Alglave <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Luc Maranget <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: [email protected]
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
|
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This patch improves the comments in tools/memory-model/lock.cat. In
addition to making the text more uniform and removing redundant
comments, it adds a description of all the possible locking events
that herd can generate.
Tested-by: Andrea Parri <[email protected]>
Signed-off-by: Alan Stern <[email protected]>
Signed-off-by: Paul E. McKenney <[email protected]>
Cc: Akira Yokosawa <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Boqun Feng <[email protected]>
Cc: David Howells <[email protected]>
Cc: Jade Alglave <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Luc Maranget <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: [email protected]
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
|
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This patch simplifies the implementation of spin_is_locked in the
LKMM. It capitalizes on the fact that a failed spin_trylock() and a
spin_is_locked() which returns True have exactly the same semantics
(those of READ_ONCE) and ordering properties (none). Therefore the
two kinds of events can be combined and handled by the same code,
instead of treated separately as they are currently.
Tested-by: Andrea Parri <[email protected]>
Signed-off-by: Alan Stern <[email protected]>
Signed-off-by: Paul E. McKenney <[email protected]>
Cc: Akira Yokosawa <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Boqun Feng <[email protected]>
Cc: David Howells <[email protected]>
Cc: Jade Alglave <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Luc Maranget <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: [email protected]
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
|
|
This commit flags WRC+pooncerelease+rmbonceonce+Once.litmus
as being forbidden by smp_store_release() A-cumulativity and
IRIW+mbonceonces+OnceOnce.litmus as being forbidden by the LKMM
propagation rule.
Suggested-by: Andrea Parri <[email protected]>
Reported-by: Paolo Bonzini <[email protected]>
[ paulmck: Updated wording as suggested by Alan Stern. ]
Signed-off-by: Paul E. McKenney <[email protected]>
Acked-by: Alan Stern <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
|
|
This commit first adds a trivial macro for spin_is_locked() to
linux-kernel.def.
It also adds cat code for enumerating all possible matches of lock
write events (set LKW) with islocked events returning true (set RL,
for Read from Lock), and unlock write events (set UL) with islocked
events returning false (set RU, for Read from Unlock). Note that this
intentionally does not model uniprocessor kernels (CONFIG_SMP=n) built
with CONFIG_DEBUG_SPINLOCK=n, in which spin_is_locked() unconditionally
returns zero.
It also adds a pair of litmus tests demonstrating the minimal ordering
provided by spin_is_locked() in conjunction with spin_lock(). Will Deacon
noted that this minimal ordering happens on ARMv8:
https://lkml.kernel.org/r/[email protected]
Notice that herd7 installations strictly older than version 7.49
do not handle the new constructs.
Signed-off-by: Luc Maranget <[email protected]>
Signed-off-by: Paul E. McKenney <[email protected]>
Reviewed-by: Alan Stern <[email protected]>
Cc: Akira Yokosawa <[email protected]>
Cc: Andrea Parri <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Boqun Feng <[email protected]>
Cc: David Howells <[email protected]>
Cc: Jade Alglave <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Luc Maranget <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
|