Merge fixes from Andrew Morton:
"4 fixes"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
mm: thp: calculate the mapcount correctly for THP pages during WP faults
ksm: fix conflict between mmput and scan_get_next_rmap_item
ocfs2: fix posix_acl_create deadlock
ocfs2: revert using ocfs2_acl_chmod to avoid inode cluster lock hang
This will provide fully accuracy to the mapcount calculation in the
write protect faults, so page pinning will not get broken by false
positive copy-on-writes.
total_mapcount() isn't the right calculation needed in
reuse_swap_page(), so this introduces a page_trans_huge_mapcount()
that is effectively the full accurate return value for page_mapcount()
if dealing with Transparent Hugepages, however we only use the
page_trans_huge_mapcount() during COW faults where it strictly needed,
due to its higher runtime cost.
This also provide at practical zero cost the total_mapcount
information which is needed to know if we can still relocate the page
anon_vma to the local vma. If page_trans_huge_mapcount() returns 1 we
can reuse the page no matter if it's a pte or a pmd_trans_huge
triggering the fault, but we can only relocate the page anon_vma to
the local vma->anon_vma if we're sure it's only this "vma" mapping the
whole THP physical range.
Kirill A. Shutemov discovered the problem with moving the page
anon_vma to the local vma->anon_vma in a previous version of this
patch and another problem in the way page_move_anon_rmap() was called.
Andrew Morton discovered that CONFIG_SWAP=n wouldn't build in a
previous version, because reuse_swap_page must be a macro to call
page_trans_huge_mapcount from swap.h, so this uses a macro again
instead of an inline function. With this change at least it's a less
dangerous usage than it was before, because "page" is used only once
now, while with the previous code reuse_swap_page(page++) would have
called page_mapcount on page+1 and it would have increased page twice
instead of just once.
Dean Luick noticed an uninitialized variable that could result in a
rmap inefficiency for the non-THP case in a previous version.
Mike Marciniszyn said:
: Our RDMA tests are seeing an issue with memory locking that bisects to
: commit 61f5d698cc ("mm: re-enable THP")
:
: The test program registers two rather large MRs (512M) and RDMA
: writes data to a passive peer using the first and RDMA reads it back
: into the second MR and compares that data. The sizes are chosen randomly
: between 0 and 1024 bytes.
:
: The test will get through a few (<= 4 iterations) and then gets a
: compare error.
:
: Tracing indicates the kernel logical addresses associated with the individual
: pages at registration ARE correct , the data in the "RDMA read response only"
: packets ARE correct.
:
: The "corruption" occurs when the packet crosse two pages that are not physically
: contiguous. The second page reads back as zero in the program.
:
: It looks like the user VA at the point of the compare error no longer points to
: the same physical address as was registered.
:
: This patch totally resolves the issue!
Link: http://lkml.kernel.org/r/1462547040-1737-2-git-send-email-aarcange@redhat.com
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reviewed-by: "Kirill A. Shutemov" <kirill@shutemov.name>
Reviewed-by: Dean Luick <dean.luick@intel.com>
Tested-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Tested-by: Josh Collier <josh.d.collier@intel.com>
Cc: Marc Haber <mh+linux-kernel@zugschlus.de>
Cc: <stable@vger.kernel.org> [4.5]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A concurrency issue about KSM in the function scan_get_next_rmap_item.
task A (ksmd): |task B (the mm's task):
|
mm = slot->mm; |
down_read(&mm->mmap_sem); |
|
... |
|
spin_lock(&ksm_mmlist_lock); |
|
ksm_scan.mm_slot go to the next slot; |
|
spin_unlock(&ksm_mmlist_lock); |
|mmput() ->
| ksm_exit():
|
|spin_lock(&ksm_mmlist_lock);
|if (mm_slot && ksm_scan.mm_slot != mm_slot) {
| if (!mm_slot->rmap_list) {
| easy_to_free = 1;
| ...
|
|if (easy_to_free) {
| mmdrop(mm);
| ...
|
|So this mm_struct may be freed in the mmput().
|
up_read(&mm->mmap_sem); |
As we can see above, the ksmd thread may access a mm_struct that already
been freed to the kmem_cache. Suppose a fork will get this mm_struct from
the kmem_cache, the ksmd thread then call up_read(&mm->mmap_sem), will
cause mmap_sem.count to become -1.
As suggested by Andrea Arcangeli, unmerge_and_remove_all_rmap_items has
the same SMP race condition, so fix it too. My prev fix in function
scan_get_next_rmap_item will introduce a different SMP race condition, so
just invert the up_read/spin_unlock order as Andrea Arcangeli said.
Link: http://lkml.kernel.org/r/1462708815-31301-1-git-send-email-zhouchengming1@huawei.com
Signed-off-by: Zhou Chengming <zhouchengming1@huawei.com>
Suggested-by: Andrea Arcangeli <aarcange@redhat.com>
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Geliang Tang <geliangtang@163.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Ding Tianhong <dingtianhong@huawei.com>
Cc: Li Bin <huawei.libin@huawei.com>
Cc: Zhen Lei <thunder.leizhen@huawei.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 702e5bc68a ("ocfs2: use generic posix ACL infrastructure")
refactored code to use posix_acl_create. The problem with this function
is that it is not mindful of the cluster wide inode lock making it
unsuitable for use with ocfs2 inode creation with ACLs. For example,
when used in ocfs2_mknod, this function can cause deadlock as follows.
The parent dir inode lock is taken when calling posix_acl_create ->
get_acl -> ocfs2_iop_get_acl which takes the inode lock again. This can
cause deadlock if there is a blocked remote lock request waiting for the
lock to be downconverted. And same deadlock happened in ocfs2_reflink.
This fix is to revert back using ocfs2_init_acl.
Fixes: 702e5bc68a ("ocfs2: use generic posix ACL infrastructure")
Signed-off-by: Tariq Saeed <tariq.x.saeed@oracle.com>
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Joseph Qi <joseph.qi@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 743b5f1434 ("ocfs2: take inode lock in ocfs2_iop_set/get_acl()")
introduced this issue. ocfs2_setattr called by chmod command holds
cluster wide inode lock when calling posix_acl_chmod. This latter
function in turn calls ocfs2_iop_get_acl and ocfs2_iop_set_acl. These
two are also called directly from vfs layer for getfacl/setfacl commands
and therefore acquire the cluster wide inode lock. If a remote
conversion request comes after the first inode lock in ocfs2_setattr,
OCFS2_LOCK_BLOCKED will be set. And this will cause the second call to
inode lock from the ocfs2_iop_get_acl() to block indefinetly.
The deleted version of ocfs2_acl_chmod() calls __posix_acl_chmod() which
does not call back into the filesystem. Therefore, we restore
ocfs2_acl_chmod(), modify it slightly for locking as needed, and use that
instead.
Fixes: 743b5f1434 ("ocfs2: take inode lock in ocfs2_iop_set/get_acl()")
Signed-off-by: Tariq Saeed <tariq.x.saeed@oracle.com>
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Joseph Qi <joseph.qi@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I tried to fix this before, but my previous fix was incomplete
and we can still get the same link error in randconfig builds
because of the way that Kconfig treats the
default y if MVNETA=y && MVNETA_BM_ENABLE
line that does not actually trigger when MVNETA_BM_ENABLE=m,
unlike I intended.
Changing the line to use MVNETA_BM_ENABLE!=n however has
the desired effect and hopefully makes all configurations
work as expected.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 019ded3aa7 ("net: mvneta: bm: clarify dependencies")
Acked-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is a pretty boring pull request as you wish: including a few
small and trivial HD-audio and USB-audio quirks and a couple of small
regression fixes in HD-audio.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2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=lhNO
-----END PGP SIGNATURE-----
Merge tag 'sound-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound
Pull sound fixes from Takashi Iwai:
"This is a pretty boring pull request as you wish: including a few
small and trivial HD-audio and USB-audio quirks and a couple of small
regression fixes in HD-audio"
* tag 'sound-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
ALSA: usb-audio: Yet another Phoneix Audio device quirk
ALSA: hda - Fix regression on ATI HDMI audio
ALSA: hda - Fix subwoofer pin on ASUS N751 and N551
ALSA: hda - Fix broken reconfig
ALSA: hda - Fix white noise on Asus UX501VW headset
ALSA: usb-audio: Quirk for yet another Phoenix Audio devices (v2)
After 0161028b7c ("perf/core: Change the default paranoia level to 2")
'perf stat' fails for users without CAP_SYS_ADMIN, so just use
'perf_evsel__fallback()' to have the same behaviour as 'perf record',
i.e. set perf_event_attr.exclude_kernel to 1.
Now:
[acme@jouet linux]$ perf stat usleep 1
Performance counter stats for 'usleep 1':
0.352536 task-clock:u (msec) # 0.423 CPUs utilized
0 context-switches:u # 0.000 K/sec
0 cpu-migrations:u # 0.000 K/sec
49 page-faults:u # 0.139 M/sec
309,407 cycles:u # 0.878 GHz
243,791 instructions:u # 0.79 insn per cycle
49,622 branches:u # 140.757 M/sec
3,884 branch-misses:u # 7.83% of all branches
0.000834174 seconds time elapsed
[acme@jouet linux]$
Reported-by: Ingo Molnar <mingo@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-b20jmx4dxt5hpaa9t2rroi0o@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Now with the default for the kernel.perf_event_paranoid sysctl being 2 [1]
we need to fall back to :u, i.e. to set perf_event_attr.exclude_kernel
to 1.
Before:
[acme@jouet linux]$ perf record usleep 1
Error:
You may not have permission to collect stats.
Consider tweaking /proc/sys/kernel/perf_event_paranoid,
which controls use of the performance events system by
unprivileged users (without CAP_SYS_ADMIN).
The current value is 2:
-1: Allow use of (almost) all events by all users
>= 0: Disallow raw tracepoint access by users without CAP_IOC_LOCK
>= 1: Disallow CPU event access by users without CAP_SYS_ADMIN
>= 2: Disallow kernel profiling by users without CAP_SYS_ADMIN
[acme@jouet linux]$
After:
[acme@jouet linux]$ perf record usleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.016 MB perf.data (7 samples) ]
[acme@jouet linux]$ perf evlist
cycles:u
[acme@jouet linux]$ perf evlist -v
cycles:u: size: 112, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|PERIOD, disabled: 1, inherit: 1, exclude_kernel: 1, mmap: 1, comm: 1, freq: 1, enable_on_exec: 1, task: 1, sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1
[acme@jouet linux]$
And if the user turns on verbose mode, an explanation will appear:
[acme@jouet linux]$ perf record -v usleep 1
Warning:
kernel.perf_event_paranoid=2, trying to fall back to excluding kernel samples
mmap size 528384B
[ perf record: Woken up 1 times to write data ]
Looking at the vmlinux_path (8 entries long)
Using /lib/modules/4.6.0-rc7+/build/vmlinux for symbols
[ perf record: Captured and wrote 0.016 MB perf.data (7 samples) ]
[acme@jouet linux]$
[1] 0161028b7c ("perf/core: Change the default paranoia level to 2")
Reported-by: Ingo Molnar <mingo@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-b20jmx4dxt5hpaa9t2rroi0o@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Switch the order of the loops to walk the rates on the top
so we exhaust all DP 1.1 rate/lane combinations before trying
DP 1.2 rate/lane combos.
This avoids selecting rates that are supported by the monitor,
but not the connector leading to valid modes getting rejected.
bug:
https://bugs.freedesktop.org/show_bug.cgi?id=95206
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Switch the order of the loops to walk the rates on the top
so we exhaust all DP 1.1 rate/lane combinations before trying
DP 1.2 rate/lane combos.
This avoids selecting rates that are supported by the monitor,
but not the connector leading to valid modes getting rejected.
bug:
https://bugs.freedesktop.org/show_bug.cgi?id=95206
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
We were showing a hardcoded default value for the kernel.perf_event_paranoid
sysctl, now that it became more paranoid (1 -> 2 [1]), this would need to be
updated, instead show the current value:
[acme@jouet linux]$ perf record ls
Error:
You may not have permission to collect stats.
Consider tweaking /proc/sys/kernel/perf_event_paranoid,
which controls use of the performance events system by
unprivileged users (without CAP_SYS_ADMIN).
The current value is 2:
-1: Allow use of (almost) all events by all users
>= 0: Disallow raw tracepoint access by users without CAP_IOC_LOCK
>= 1: Disallow CPU event access by users without CAP_SYS_ADMIN
>= 2: Disallow kernel profiling by users without CAP_SYS_ADMIN
[acme@jouet linux]$
[1] 0161028b7c ("perf/core: Change the default paranoia level to 2")
Reported-by: Ingo Molnar <mingo@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-0gc4rdpg8d025r5not8s8028@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
- The pull up/down logic for the AT91 PIO4 controller was tilted:
we need to mask the reverse pull when unmasking a pull direction.
Setting both pull up & pull down is illegal and makes no sense.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1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=Kzzn
-----END PGP SIGNATURE-----
Merge tag 'pinctrl-v4.6-4' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl
Pull pinctrl fix from Linus Walleij:
"A single last pin control fix for v4.6. t's tagged for stable and
only hits a single driver with two added lines so should be safe.
Tested in linux-next.
- The pull up/down logic for the AT91 PIO4 controller was tilted: we
need to mask the reverse pull when unmasking a pull direction.
Setting both pull up & pull down is illegal and makes no sense"
* tag 'pinctrl-v4.6-4' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl:
pinctrl: at91-pio4: fix pull-up/down logic
------------[ cut here ]------------
WARNING: CPU: 0 PID: 16 at kernel/workqueue.c:4559 rebind_workers+0x1c0/0x1d0
Modules linked in:
CPU: 0 PID: 16 Comm: cpuhp/0 Not tainted 4.6.0-rc4+ #31
Hardware name: IBM IBM System x3550 M4 Server -[7914IUW]-/00Y8603, BIOS -[D7E128FUS-1.40]- 07/23/2013
0000000000000000 ffff881037babb58 ffffffff8139d885 0000000000000010
0000000000000000 0000000000000000 0000000000000000 ffff881037babba8
ffffffff8108505d ffff881037ba0000 000011cf3e7d6e60 0000000000000046
Call Trace:
dump_stack+0x89/0xd4
__warn+0xfd/0x120
warn_slowpath_null+0x1d/0x20
rebind_workers+0x1c0/0x1d0
workqueue_cpu_up_callback+0xf5/0x1d0
notifier_call_chain+0x64/0x90
? trace_hardirqs_on_caller+0xf2/0x220
? notify_prepare+0x80/0x80
__raw_notifier_call_chain+0xe/0x10
__cpu_notify+0x35/0x50
notify_down_prepare+0x5e/0x80
? notify_prepare+0x80/0x80
cpuhp_invoke_callback+0x73/0x330
? __schedule+0x33e/0x8a0
cpuhp_down_callbacks+0x51/0xc0
cpuhp_thread_fun+0xc1/0xf0
smpboot_thread_fn+0x159/0x2a0
? smpboot_create_threads+0x80/0x80
kthread+0xef/0x110
? wait_for_completion+0xf0/0x120
? schedule_tail+0x35/0xf0
ret_from_fork+0x22/0x50
? __init_kthread_worker+0x70/0x70
---[ end trace eb12ae47d2382d8f ]---
notify_down_prepare: attempt to take down CPU 0 failed
This bug can be reproduced by below config w/ nohz_full= all cpus:
CONFIG_BOOTPARAM_HOTPLUG_CPU0=y
CONFIG_DEBUG_HOTPLUG_CPU0=y
CONFIG_NO_HZ_FULL=y
As Thomas pointed out:
| If a down prepare callback fails, then DOWN_FAILED is invoked for all
| callbacks which have successfully executed DOWN_PREPARE.
|
| But, workqueue has actually two notifiers. One which handles
| UP/DOWN_FAILED/ONLINE and one which handles DOWN_PREPARE.
|
| Now look at the priorities of those callbacks:
|
| CPU_PRI_WORKQUEUE_UP = 5
| CPU_PRI_WORKQUEUE_DOWN = -5
|
| So the call order on DOWN_PREPARE is:
|
| CB 1
| CB ...
| CB workqueue_up() -> Ignores DOWN_PREPARE
| CB ...
| CB X ---> Fails
|
| So we call up to CB X with DOWN_FAILED
|
| CB 1
| CB ...
| CB workqueue_up() -> Handles DOWN_FAILED
| CB ...
| CB X-1
|
| So the problem is that the workqueue stuff handles DOWN_FAILED in the up
| callback, while it should do it in the down callback. Which is not a good idea
| either because it wants to be called early on rollback...
|
| Brilliant stuff, isn't it? The hotplug rework will solve this problem because
| the callbacks become symetric, but for the existing mess, we need some
| workaround in the workqueue code.
The boot CPU handles housekeeping duty(unbound timers, workqueues,
timekeeping, ...) on behalf of full dynticks CPUs. It must remain
online when nohz full is enabled. There is a priority set to every
notifier_blocks:
workqueue_cpu_up > tick_nohz_cpu_down > workqueue_cpu_down
So tick_nohz_cpu_down callback failed when down prepare cpu 0, and
notifier_blocks behind tick_nohz_cpu_down will not be called any
more, which leads to workers are actually not unbound. Then hotplug
state machine will fallback to undo and online cpu 0 again. Workers
will be rebound unconditionally even if they are not unbound and
trigger the warning in this progress.
This patch fix it by catching !DISASSOCIATED to avoid rebind bound
workers.
Cc: Tejun Heo <tj@kernel.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: stable@vger.kernel.org
Suggested-by: Lai Jiangshan <jiangshanlai@gmail.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
- fix a regression on the clock subsystem while switching to syscon/regmap
due to a stricter check of the register map.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.11 (GNU/Linux)
iQEcBAABAgAGBQJXM0NyAAoJEAf03oE53VmQ0IwIAI05Acjbko78+Hm/kWHlbJrx
5BLpJqTGLavbjbPjFnElKTr1c8m7Bgd6HNcat/2z9ZNh8/82FXyGOjYSp4W0BE9V
ovyD/lz/2fZyom4YLJjdCnVkwIV1pKHS+uNxy5zXMY2gJfz4VRtUh54H3ArdaQOE
LOKvrVl9bGorLbzbTpH0rSeKqQ1XFGPDlp1A3GUtI6646RWd5Eqe6zDzgQUwWJis
AR+sAcsqVb+IWY5rZwMyL0oZ1kjnEw4tihDTy+G+eBXRdRMYqSgEt8dBz65T3VYi
5EFXLuLjknnf3qVaxEU+og6kiJkefTYdB4I7xVR+dKbcILBSSqdHxlG1HmNkBQ4=
=CF/9
-----END PGP SIGNATURE-----
Merge tag 'at91-fixes2' of git://git.kernel.org/pub/scm/linux/kernel/git/nferre/linux-at91 into fixes
Merge "Second AT91 fix PR for 4.6" from Nicolas Ferre:
- fix a regression on the clock subsystem while switching to syscon/regmap
due to a stricter check of the register map.
* tag 'at91-fixes2' of git://git.kernel.org/pub/scm/linux/kernel/git/nferre/linux-at91:
ARM: dts: at91: sam9x5: Fix the memory range assigned to the PMC
commit 4f41fc5962 ("cgroup, kernfs: make mountinfo
show properly scoped path for cgroup namespaces")
added the following compile warning:
kernel/cgroup.c: In function ‘cgroup_show_path’:
kernel/cgroup.c:1634:15: warning: unused variable ‘ret’ [-Wunused-variable]
int len = 0, ret = 0;
^
fix it.
Fixes: 4f41fc5962 ("cgroup, kernfs: make mountinfo show properly scoped path for cgroup namespaces")
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Our caller expects 0 on success, not >0.
This fixes a bug in the patch
cgroup, kernfs: make mountinfo show properly scoped path for cgroup namespaces
where /sys does not show up in mountinfo, breaking criu.
Thanks for catching this, Andrei.
Reported-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
At the end of process_filter(), collapse_tree() was changed to update
the parg parameter, but the reassignment after the call wasn't removed.
What happens is that the "current_op" gets modified and freed and parg
is assigned to the new allocated argument. But after the call to
collapse_tree(), parg is assigned again to the just freed "current_op",
and this causes the tool to crash.
The current_op variable must also be assigned to NULL in case of error,
otherwise it will cause it to be free()ed twice.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: stable@vger.kernel.org # 3.14+
Fixes: 42d6194d13 ("tools lib traceevent: Refactor process_filter()")
Link: http://lkml.kernel.org/r/20160511150936.678c18a1@gandalf.local.home
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
If not, tell the user that:
config/Makefile:273: Old libdw.h, finding variables at given 'perf probe' point will not work, install elfutils-devel/libdw-dev >= 0.157
And return -ENOTSUPP in die_get_var_range(), failing features that
need it, like the one pointed out above.
This fixes the build on older systems, such as Ubuntu 12.04.5.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Vinson Lee <vlee@freedesktop.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-9l7luqkq4gfnx7vrklkq4obs@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To fix the build on Fedora Rawhide (gcc 6.0.0 20160311 (Red Hat 6.0.0-0.17):
CC /tmp/build/perf/arch/x86/util/dwarf-regs.o
arch/x86/util/dwarf-regs.c:66:36: error: 'x86_32_regoffset_table' defined but not used [-Werror=unused-const-variable=]
static const struct pt_regs_offset x86_32_regoffset_table[] = {
^~~~~~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-fghuksc1u8ln82bof4lwcj0o@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The readdir() function is thread safe as long as just one thread uses a
DIR, which is the case when parsing tracepoint event definitions, to
avoid breaking the build with glibc-2.23.90 (upcoming 2.24), use it
instead of readdir_r().
See: http://man7.org/linux/man-pages/man3/readdir.3.html
"However, in modern implementations (including the glibc implementation),
concurrent calls to readdir() that specify different directory streams
are thread-safe. In cases where multiple threads must read from the
same directory stream, using readdir() with external synchronization is
still preferable to the use of the deprecated readdir_r(3) function."
Noticed while building on a Fedora Rawhide docker container.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-wddn49r6bz6wq4ee3dxbl7lo@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The readdir() function is thread safe as long as just one thread uses a
DIR, which is the case in thread_map, so, to avoid breaking the build
with glibc-2.23.90 (upcoming 2.24), use it instead of readdir_r().
See: http://man7.org/linux/man-pages/man3/readdir.3.html
"However, in modern implementations (including the glibc implementation),
concurrent calls to readdir() that specify different directory streams
are thread-safe. In cases where multiple threads must read from the
same directory stream, using readdir() with external synchronization is
still preferable to the use of the deprecated readdir_r(3) function."
Noticed while building on a Fedora Rawhide docker container.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-del8h2a0f40z75j4r42l96l0@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The readdir() function is thread safe as long as just one thread uses a
DIR, which is the case in 'perf script', so, to avoid breaking the build
with glibc-2.23.90 (upcoming 2.24), use it instead of readdir_r().
See: http://man7.org/linux/man-pages/man3/readdir.3.html
"However, in modern implementations (including the glibc implementation),
concurrent calls to readdir() that specify different directory streams
are thread-safe. In cases where multiple threads must read from the
same directory stream, using readdir() with external synchronization is
still preferable to the use of the deprecated readdir_r(3) function."
Noticed while building on a Fedora Rawhide docker container.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-mt3xz7n2hl49ni2vx7kuq74g@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The readdir() function is thread safe as long as just one thread uses a
DIR, which is the case when synthesizing events for pre-existing threads
by traversing /proc, so, to avoid breaking the build with glibc-2.23.90
(upcoming 2.24), use it instead of readdir_r().
See: http://man7.org/linux/man-pages/man3/readdir.3.html
"However, in modern implementations (including the glibc implementation),
concurrent calls to readdir() that specify different directory streams
are thread-safe. In cases where multiple threads must read from the
same directory stream, using readdir() with external synchronization is
still preferable to the use of the deprecated readdir_r(3) function."
Noticed while building on a Fedora Rawhide docker container.
CC /tmp/build/perf/util/event.o
util/event.c: In function '__event__synthesize_thread':
util/event.c:466:2: error: 'readdir_r' is deprecated [-Werror=deprecated-declarations]
while (!readdir_r(tasks, &dirent, &next) && next) {
^~~~~
In file included from /usr/include/features.h:368:0,
from /usr/include/stdint.h:25,
from /usr/lib/gcc/x86_64-redhat-linux/6.0.0/include/stdint.h:9,
from /git/linux/tools/include/linux/types.h:6,
from util/event.c:1:
/usr/include/dirent.h:189:12: note: declared here
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-i1vj7nyjp2p750rirxgrfd3c@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When the PMU driver reports a truncated AUX record, it effectively means
that there is no more usable room in the event's AUX buffer (even though
there may still be some room, so that perf_aux_output_begin() doesn't take
action). At this point the consumer still has to be woken up and the event
has to be disabled, otherwise the event will just keep spinning between
perf_aux_output_begin() and perf_aux_output_end() until its context gets
unscheduled.
Again, for cpu-wide events this means never, so once in this condition,
they will be forever losing data.
Fix this by disabling the event and waking up the consumer in case of a
truncated AUX record.
Reported-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: vince@deater.net
Link: http://lkml.kernel.org/r/1462886313-13660-3-git-send-email-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Currently, the PT driver always sets the PMI bit one region (page) before
the STOP region so that we can wake up the consumer before we run out of
room in the buffer and have to disable the event. However, we also need
an interrupt in the last output region, so that we actually get to disable
the event (if no more room from new data is available at that point),
otherwise hardware just quietly refuses to start, but the event is
scheduled in and we end up losing trace data till the event gets removed.
For a cpu-wide event it is even worse since there may not be any
re-scheduling at all and no chance for the ring buffer code to notice
that its buffer is filled up and the event needs to be disabled (so that
the consumer can re-enable it when it finishes reading the data out). In
other words, all the trace data will be lost after the buffer gets filled
up.
This patch makes PT also generate a PMI when the last output region is
full.
Reported-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: vince@deater.net
Link: http://lkml.kernel.org/r/1462886313-13660-2-git-send-email-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Similar to preadv and pwritev, preadv2 and pwritev2 need compat entries
in the 32-bit syscall table.
This bug was found by strace test suite.
Fixes: 4babf2c5ef ("x86: wire up preadv2 and pwritev2")
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
Acked-by: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20160511084817.GA29823@altlinux.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This fixes CVE-2016-0758.
In the ASN.1 decoder, when the length field of an ASN.1 value is extracted,
it isn't validated against the remaining amount of data before being added
to the cursor. With a sufficiently large size indicated, the check:
datalen - dp < 2
may then fail due to integer overflow.
Fix this by checking the length indicated against the amount of remaining
data in both places a definite length is determined.
Whilst we're at it, make the following changes:
(1) Check the maximum size of extended length does not exceed the capacity
of the variable it's being stored in (len) rather than the type that
variable is assumed to be (size_t).
(2) Compare the EOC tag to the symbolic constant ASN1_EOC rather than the
integer 0.
(3) To reduce confusion, move the initialisation of len outside of:
for (len = 0; n > 0; n--) {
since it doesn't have anything to do with the loop counter n.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: David Woodhouse <David.Woodhouse@intel.com>
Acked-by: Peter Jones <pjones@redhat.com>
When the PMU driver reports a truncated AUX record, it effectively means
that there is no more usable room in the event's AUX buffer (even though
there may still be some room, so that perf_aux_output_begin() doesn't take
action). At this point the consumer still has to be woken up and the event
has to be disabled, otherwise the event will just keep spinning between
perf_aux_output_begin() and perf_aux_output_end() until its context gets
unscheduled.
Again, for cpu-wide events this means never, so once in this condition,
they will be forever losing data.
Fix this by disabling the event and waking up the consumer in case of a
truncated AUX record.
Reported-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: vince@deater.net
Link: http://lkml.kernel.org/r/1462886313-13660-3-git-send-email-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Currently, the PT driver always sets the PMI bit one region (page) before
the STOP region so that we can wake up the consumer before we run out of
room in the buffer and have to disable the event. However, we also need
an interrupt in the last output region, so that we actually get to disable
the event (if no more room from new data is available at that point),
otherwise hardware just quietly refuses to start, but the event is
scheduled in and we end up losing trace data till the event gets removed.
For a cpu-wide event it is even worse since there may not be any
re-scheduling at all and no chance for the ring buffer code to notice
that its buffer is filled up and the event needs to be disabled (so that
the consumer can re-enable it when it finishes reading the data out). In
other words, all the trace data will be lost after the buffer gets filled
up.
This patch makes PT also generate a PMI when the last output region is
full.
Reported-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: vince@deater.net
Link: http://lkml.kernel.org/r/1462886313-13660-2-git-send-email-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Jim reported:
UBSAN: Undefined behaviour in arch/x86/events/intel/core.c:3708:12
shift exponent 35 is too large for 32-bit type 'long unsigned int'
The use of 'unsigned long' type obviously is not correct here, make it
'unsigned long long' instead.
Reported-by: Jim Cromie <jim.cromie@gmail.com>
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Imre Palik <imrep@amazon.de>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Fixes: 2c33645d36 ("perf/x86: Honor the architectural performance monitoring version")
Link: http://lkml.kernel.org/r/1462974711-10037-1-git-send-email-aryabinin@virtuozzo.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We compute 'delta' and properly sign extend it and then ignore it and
recompute the raw value, loosing the sign extention.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
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: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: kan.liang@intel.com
Cc: linux-kernel@vger.kernel.org
Cc: luto@kernel.org
Cc: ray.huang@amd.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
tsk_nr_cpus_allowed() is an accessor for task->nr_cpus_allowed which allows
us to change the representation of ->nr_cpus_allowed if required.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1462969411-17735-2-git-send-email-bigeasy@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Use the future-safe accessor for struct task_struct's.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1462969411-17735-1-git-send-email-bigeasy@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Systems show a minimal load average of 0.00, 0.01, 0.05 even when they
have no load at all.
Uptime and /proc/loadavg on all systems with kernels released during the
last five years up until kernel version 4.6-rc5, show a 5- and 15-minute
minimum loadavg of 0.01 and 0.05 respectively. This should be 0.00 on
idle systems, but the way the kernel calculates this value prevents it
from getting lower than the mentioned values.
Likewise but not as obviously noticeable, a fully loaded system with no
processes waiting, shows a maximum 1/5/15 loadavg of 1.00, 0.99, 0.95
(multiplied by number of cores).
Once the (old) load becomes 93 or higher, it mathematically can never
get lower than 93, even when the active (load) remains 0 forever.
This results in the strange 0.00, 0.01, 0.05 uptime values on idle
systems. Note: 93/2048 = 0.0454..., which rounds up to 0.05.
It is not correct to add a 0.5 rounding (=1024/2048) here, since the
result from this function is fed back into the next iteration again,
so the result of that +0.5 rounding value then gets multiplied by
(2048-2037), and then rounded again, so there is a virtual "ghost"
load created, next to the old and active load terms.
By changing the way the internally kept value is rounded, that internal
value equivalent now can reach 0.00 on idle, and 1.00 on full load. Upon
increasing load, the internally kept load value is rounded up, when the
load is decreasing, the load value is rounded down.
The modified code was tested on nohz=off and nohz kernels. It was tested
on vanilla kernel 4.6-rc5 and on centos 7.1 kernel 3.10.0-327. It was
tested on single, dual, and octal cores system. It was tested on virtual
hosts and bare hardware. No unwanted effects have been observed, and the
problems that the patch intended to fix were indeed gone.
Tested-by: Damien Wyart <damien.wyart@free.fr>
Signed-off-by: Vik Heyndrickx <vik.heyndrickx@veribox.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Cc: Doug Smythies <dsmythies@telus.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 0f004f5a69 ("sched: Cure more NO_HZ load average woes")
Link: http://lkml.kernel.org/r/e8d32bff-d544-7748-72b5-3c86cc71f09f@veribox.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
In calculate_imbalance() load_above_capacity currently has the unit
[capacity] while it is used as being [load/capacity]. Not only is it
wrong it also makes it unlikely that load_above_capacity is ever used
as the subsequent code picks the smaller of load_above_capacity and
the avg_load
This patch ensures that load_above_capacity has the right unit
[load/capacity].
Signed-off-by: Morten Rasmussen <morten.rasmussen@arm.com>
[ Changed changelog to note it was in capacity unit; +rebase. ]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1461958364-675-4-git-send-email-dietmar.eggemann@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Wanpeng noted that the scale_load_down() in calculate_imbalance() was
weird. I agree, it should be SCHED_CAPACITY_SCALE, since we're going
to compare against busiest->group_capacity, which is in [capacity]
units.
Reported-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Morten Rasmussen <morten.rasmussen@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yuyang Du <yuyang.du@intel.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The following commit:
9642d18eee ("nohz: Affine unpinned timers to housekeepers")'
intended to affine unpinned timers to housekeepers:
unpinned timers(full dynaticks, idle) => nearest busy housekeepers(otherwise, fallback to any housekeepers)
unpinned timers(full dynaticks, busy) => nearest busy housekeepers(otherwise, fallback to any housekeepers)
unpinned timers(houserkeepers, idle) => nearest busy housekeepers(otherwise, fallback to itself)
However, the !idle_cpu(i) && is_housekeeping_cpu(cpu) check modified the
intention to:
unpinned timers(full dynaticks, idle) => any housekeepers(no mattter cpu topology)
unpinned timers(full dynaticks, busy) => any housekeepers(no mattter cpu topology)
unpinned timers(housekeepers, idle) => any busy cpus(otherwise, fallback to any housekeepers)
This patch fixes it by checking if there are busy housekeepers nearby,
otherwise falls to any housekeepers/itself. After the patch:
unpinned timers(full dynaticks, idle) => nearest busy housekeepers(otherwise, fallback to any housekeepers)
unpinned timers(full dynaticks, busy) => nearest busy housekeepers(otherwise, fallback to any housekeepers)
unpinned timers(housekeepers, idle) => nearest busy housekeepers(otherwise, fallback to itself)
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
[ Fixed the changelog. ]
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Fixes: 'commit 9642d18eee ("nohz: Affine unpinned timers to housekeepers")'
Link: http://lkml.kernel.org/r/1462344334-8303-1-git-send-email-wanpeng.li@hotmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pavan reported that in the presence of very light tasks (or cgroups)
the placement of migrated tasks can cause severe fairness issues.
The problem is that enqueue_entity() places the task before it updates
time, thereby it can place the task far in the past (remember that
light tasks will shoot virtual time forward at a high speed, so in
relation to the pre-existing light task, we can land far in the past).
This is done because update_curr() needs the current task, and we
might be placing the current task.
The obvious solution is to differentiate between the current and any
other task; placing the current before we update time, and placing any
other task after, such that !curr tasks end up at the current moment
in time, and not in the past.
This commit re-introduces the previously reverted commit:
3a47d5124a ("sched/fair: Fix fairness issue on migration")
... which is now safe to do, after we've also fixed another
underlying bug first, in:
sched/fair: Prepare to fix fairness problems on migration
and cleaned up other details in the migration code:
sched/core: Kill sched_class::task_waking
Reported-by: Pavan Kondeti <pkondeti@codeaurora.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
With sched_class::task_waking being called only when we do
set_task_cpu(), we can make sched_class::migrate_task_rq() do the work
and eliminate sched_class::task_waking entirely.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Hunter <ahh@google.com>
Cc: Ben Segall <bsegall@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: Morten Rasmussen <morten.rasmussen@arm.com>
Cc: Paul Turner <pjt@google.com>
Cc: Pavan Kondeti <pkondeti@codeaurora.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: byungchul.park@lge.com
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Mike reported that our recent attempt to fix migration problems:
3a47d5124a ("sched/fair: Fix fairness issue on migration")
broke interactivity and the signal starve test. We reverted that
commit and now let's try it again more carefully, with some other
underlying problems fixed first.
One problem is that I assumed ENQUEUE_WAKING was only set when we do a
cross-cpu wakeup (migration), which isn't true. This means we now
destroy the vruntime history of tasks and wakeup-preemption suffers.
Cure this by making my assumption true, only call
sched_class::task_waking() when we do a cross-cpu wakeup. This avoids
the indirect call in the case we do a local wakeup.
Reported-by: Mike Galbraith <mgalbraith@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Hunter <ahh@google.com>
Cc: Ben Segall <bsegall@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Morten Rasmussen <morten.rasmussen@arm.com>
Cc: Paul Turner <pjt@google.com>
Cc: Pavan Kondeti <pkondeti@codeaurora.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: byungchul.park@lge.com
Cc: linux-kernel@vger.kernel.org
Fixes: 3a47d5124a ("sched/fair: Fix fairness issue on migration")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Since I want to make ->task_woken() conditional on the task getting
migrated, we cannot use it to call record_wakee().
Move it to select_task_rq_fair(), which gets called in almost all the
same conditions. The only exception is if the woken task (@p) is
CPU-bound (as per the nr_cpus_allowed test in select_task_rq()).
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Hunter <ahh@google.com>
Cc: Ben Segall <bsegall@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: Morten Rasmussen <morten.rasmussen@arm.com>
Cc: Paul Turner <pjt@google.com>
Cc: Pavan Kondeti <pkondeti@codeaurora.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: byungchul.park@lge.com
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Use X86_FEATURE_SMCA when detecting if SMCA is available instead of
directly using CPUID 0x80000007_EBX.
Signed-off-by: Yazen Ghannam <Yazen.Ghannam@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1462971509-3856-7-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
