- 15 May, 2019 40 commits
-
-
Johannes Weiner authored
When a cgroup is reclaimed on behalf of a configured limit, reclaim needs to round-robin through all NUMA nodes that hold pages of the memcg in question. However, when assembling the mask of candidate NUMA nodes, the code only consults the *local* cgroup LRU counters, not the recursive counters for the entire subtree. Cgroup limits are frequently configured against intermediate cgroups that do not have memory on their own LRUs. In this case, the node mask will always come up empty and reclaim falls back to scanning only the current node. If a cgroup subtree has some memory on one node but the processes are bound to another node afterwards, the limit reclaim will never age or reclaim that memory anymore. To fix this, use the recursive LRU counts for a cgroup subtree to determine which nodes hold memory of that cgroup. The code has been broken like this forever, so it doesn't seem to be a problem in practice. I just noticed it while reviewing the way the LRU counters are used in general. Link: http://lkml.kernel.org/r/20190412151507.2769-5-hannes@cmpxchg.orgSigned-off-by:
Johannes Weiner <hannes@cmpxchg.org> Reviewed-by:
Shakeel Butt <shakeelb@google.com> Reviewed-by:
Roman Gushchin <guro@fb.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
-
Johannes Weiner authored
Right now, when somebody needs to know the recursive memory statistics and events of a cgroup subtree, they need to walk the entire subtree and sum up the counters manually. There are two issues with this: 1. When a cgroup gets deleted, its stats are lost. The state counters should all be 0 at that point, of course, but the events are not. When this happens, the event counters, which are supposed to be monotonic, can go backwards in the parent cgroups. 2. During regular operation, we always have a certain number of lazily freed cgroups sitting around that have been deleted, have no tasks, but have a few cache pages remaining. These groups' statistics do not change until we eventually hit memory pressure, but somebody watching, say, memory.stat on an ancestor has to iterate those every time. This patch addresses both issues by introducing recursive counters at each level that are propagated from the write side when stats change. Upward propagation happens when the per-cpu caches spill over into the local atomic counter. This is the same thing we do during charge and uncharge, except that the latter uses atomic RMWs, which are more expensive; stat changes happen at around the same rate. In a sparse file test (page faults and reclaim at maximum CPU speed) with 5 cgroup nesting levels, perf shows __mod_memcg_page state at ~1%. Link: http://lkml.kernel.org/r/20190412151507.2769-4-hannes@cmpxchg.orgSigned-off-by:
-
Johannes Weiner authored
These are getting too big to be inlined in every callsite. They were stolen from vmstat.c, which already out-of-lines them, and they have only been growing since. The callsites aren't that hot, either. Move __mod_memcg_state() __mod_lruvec_state() and __count_memcg_events() out of line and add kerneldoc comments. Link: http://lkml.kernel.org/r/20190412151507.2769-3-hannes@cmpxchg.orgSigned-off-by: -
Johannes Weiner authored
Patch series "mm: memcontrol: memory.stat cost & correctness". The cgroup memory.stat file holds recursive statistics for the entire subtree. The current implementation does this tree walk on-demand whenever the file is read. This is giving us problems in production. 1. The cost of aggregating the statistics on-demand is high. A lot of system service cgroups are mostly idle and their stats don't change between reads, yet we always have to check them. There are also always some lazily-dying cgroups sitting around that are pinned by a handful of remaining page cache; the same applies to them. In an application that periodically monitors memory.stat in our fleet, we have seen the aggregation consume up to 5% CPU time. 2. When cgroups die and disappear from the cgroup tree, so do their accumulated vm events. The result is that the event counters at higher-level cgroups can go backwards and confuse some of our automation, let alone people looking at the graphs over time. To address both issues, this patch series changes the stat implementation to spill counts upwards when the counters change. The upward spilling is batched using the existing per-cpu cache. In a sparse file stress test with 5 level cgroup nesting, the additional cost of the flushing was negligible (a little under 1% of CPU at 100% CPU utilization, compared to the 5% of reading memory.stat during regular operation). This patch (of 4): memcg_page_state(), lruvec_page_state(), memcg_sum_events() are currently returning the state of the local memcg or lruvec, not the recursive state. In practice there is a demand for both versions, although the callers that want the recursive counts currently sum them up by hand. Per default, cgroups are considered recursive entities and generally we expect more users of the recursive counters, with the local counts being special cases. To reflect that in the name, add a _local suffix to the current implementations. The following patch will re-incarnate these functions with recursive semantics, but with an O(1) implementation. [hannes@cmpxchg.org: fix bisection hole] Link: http://lkml.kernel.org/r/20190417160347.GC23013@cmpxchg.org Link: http://lkml.kernel.org/r/20190412151507.2769-2-hannes@cmpxchg.orgSigned-off-by:
-
Dan Carpenter authored
The "param.count" value is a u64 thatcomes from the user. The code later in the function assumes that param.count is at least one and if it's not then it leads to an Oops when we dereference the ZERO_SIZE_PTR. Also the addition can have an integer overflow which would lead us to allocate a smaller "pages" array than required. I can't immediately tell what the possible run times implications are, but it's safest to prevent the overflow. Link: http://lkml.kernel.org/r/20181218082129.GE32567@kadam Fixes: 6db71994 ("drivers/virt: introduce Freescale hypervisor management driver") Signed-off-by:
Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by:
-
Dan Carpenter authored
strndup_user() returns error pointers on error, and then in the error handling we pass the error pointers to kfree(). It will cause an Oops. Link: http://lkml.kernel.org/r/20181218082003.GD32567@kadam Fixes: 6db71994 ("drivers/virt: introduce Freescale hypervisor management driver") Signed-off-by:
-
Chris Down authored
I spent literally an hour trying to work out why an earlier version of my memory.events aggregation code doesn't work properly, only to find out I was calling memcg->events instead of memcg->memory_events, which is fairly confusing. This naming seems in need of reworking, so make it harder to do the wrong thing by using vmevents instead of events, which makes it more clear that these are vm counters rather than memcg-specific counters. There are also a few other inconsistent names in both the percpu and aggregated structs, so these are all cleaned up to be more coherent and easy to understand. This commit contains code cleanup only: there are no logic changes. [akpm@linux-foundation.org: fix it for preceding changes] Link: http://lkml.kernel.org/r/20190208224319.GA23801@chrisdown.nameSigned-off-by:
Chris Down <chris@chrisdown.name> Acked-by:
-
Masahiro Yamada authored
Now that all instances of #include <asm/sizes.h> have been replaced with #include <linux/sizes.h>, we can remove these. Link: http://lkml.kernel.org/r/1553267665-27228-2-git-send-email-yamada.masahiro@socionext.comSigned-off-by:
Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by:
-
Masahiro Yamada authored
Since commit dccd2304 ("ARM: 7430/1: sizes.h: move from asm-generic to <linux/sizes.h>"), <asm/sizes.h> and <asm-generic/sizes.h> are just wrappers of <linux/sizes.h>. This commit replaces all <asm/sizes.h> and <asm-generic/sizes.h> to prepare for the removal. Link: http://lkml.kernel.org/r/1553267665-27228-1-git-send-email-yamada.masahiro@socionext.comSigned-off-by:
-
Sabyasachi Gupta authored
linux/dax.h is included more than once. Link: http://lkml.kernel.org/r/5c867e95.1c69fb81.4f15a.e5e4@mx.google.comSigned-off-by:
Sabyasachi Gupta <sabyasachi.linux@gmail.com> Acked-by:
Souptick Joarder <jrdr.linux@gmail.com> Signed-off-by:
-
Sabyasachi Gupta authored
linux/xattr.h is included more than once. Link: http://lkml.kernel.org/r/5c86803d.1c69fb81.1a7c6.2b78@mx.google.comSigned-off-by:
-
Andrei Vagin authored
This file uses "task" 85 times and "tsk" 25 times. It is better to be consistent. Link: http://lkml.kernel.org/r/20181129180547.15976-1-avagin@gmail.comSigned-off-by:
Andrei Vagin <avagin@gmail.com> Reviewed-by:
-
Sabyasachi Gupta authored
linux/poll.h is included more than once. Link: http://lkml.kernel.org/r/5c86820f.1c69fb81.149f0.0834@mx.google.comSigned-off-by:
-
Manfred Spraul authored
For ipcmni_extend mode, the sequence number space is only 7 bits. So the chance of id reuse is relatively high compared with the non-extended mode. To alleviate this id reuse problem, this patch enables cyclic allocation for the index to the radix tree (idx). The disadvantage is that this can cause a slight slow-down of the fast path, as the radix tree could be higher than necessary. To limit the radix tree height, I have chosen the following limits: 1) The cycling is done over in_use*1.5. 2) At least, the cycling is done over "normal" ipcnmi mode: RADIX_TREE_MAP_SIZE elements "ipcmni_extended": 4096 elements Result: - for normal mode: No change for <= 42 active ipc elements. With more than 42 active ipc elements, a 2nd level would be added to the radix tree. Without cyclic allocation, a 2nd level would be added only with more than 63 active elements. - for extended mode: Cycling creates always at least a 2-level radix tree. With more than 2730 active objects, a 3rd level would be added, instead of > 4095 active objects until the 3rd level is added without cyclic allocation. For a 2-level radix tree compared to a 1-level radix tree, I have observed < 1% performance impact. Notes: 1) Normal "x=semget();y=semget();" is unaffected: Then the idx is e.g. a and a+1, regardless if idr_alloc() or idr_alloc_cyclic() is used. 2) The -1% happens in a microbenchmark after this situation: x=semget(); for(i=0;i<4000;i++) {t=semget();semctl(t,0,IPC_RMID);} y=semget(); Now perform semget calls on x and y that do not sleep. 3) The worst-case reuse cycle time is unfortunately unaffected: If you have 2^24-1 ipc objects allocated, and get/remove the last possible element in a loop, then the id is reused after 128 get/remove pairs. Performance check: A microbenchmark that performes no-op semop() randomly on two IDs, with only these two IDs allocated. The IDs were set using /proc/sys/kernel/sem_next_id. The test was run 5 times, averages are shown. 1 & 2: Base (6.22 seconds for 10.000.000 semops) 1 & 40: -0.2% 1 & 3348: - 0.8% 1 & 27348: - 1.6% 1 & 15777204: - 3.2% Or: ~12.6 cpu cycles per additional radix tree level. The cpu is an Intel I3-5010U. ~1300 cpu cycles/syscall is slower than what I remember (spectre impact?). V2 of the patch: - use "min" and "max" - use RADIX_TREE_MAP_SIZE * RADIX_TREE_MAP_SIZE instead of (2<<12). [akpm@linux-foundation.org: fix max() warning] Link: http://lkml.kernel.org/r/20190329204930.21620-3-longman@redhat.comSigned-off-by:Manfred Spraul <manfred@colorfullife.com> Acked-by:
Waiman Long <longman@redhat.com> Cc: "Luis R. Rodriguez" <mcgrof@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Matthew Wilcox <willy@infradead.org> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: Takashi Iwai <tiwai@suse.de> Cc: Davidlohr Bueso <dbueso@suse.de> Signed-off-by:
-
Manfred Spraul authored
Rewrite, based on the patch from Waiman Long: The mixing in of a sequence number into the IPC IDs is probably to avoid ID reuse in userspace as much as possible. With ipcmni_extend mode, the number of usable sequence numbers is greatly reduced leading to higher chance of ID reuse. To address this issue, we need to conserve the sequence number space as much as possible. Right now, the sequence number is incremented for every new ID created. In reality, we only need to increment the sequence number when new allocated ID is not greater than the last one allocated. It is in such case that the new ID may collide with an existing one. This is being done irrespective of the ipcmni mode. In order to avoid any races, the index is first allocated and then the pointer is replaced. Changes compared to the initial patch: - Handle failures from idr_alloc(). - Avoid that concurrent operations can see the wrong sequence number. (This is achieved by using idr_replace()). - IPCMNI_SEQ_SHIFT is not a constant, thus renamed to ipcmni_seq_shift(). - IPCMNI_SEQ_MAX is not a constant, thus renamed to ipcmni_seq_max(). Link: http://lkml.kernel.org/r/20190329204930.21620-2-longman@redhat.comSigned-off-by:
Matthew Wilcox <willy@infradead.org> Acked-by:
-
Waiman Long authored
The maximum number of unique System V IPC identifiers was limited to 32k. That limit should be big enough for most use cases. However, there are some users out there requesting for more, especially those that are migrating from Solaris which uses 24 bits for unique identifiers. To satisfy the need of those users, a new boot time kernel option "ipcmni_extend" is added to extend the IPCMNI value to 16M. This is a 512X increase which should be big enough for users out there that need a large number of unique IPC identifier. The use of this new option will change the pattern of the IPC identifiers returned by functions like shmget(2). An application that depends on such pattern may not work properly. So it should only be used if the users really need more than 32k of unique IPC numbers. This new option does have the side effect of reducing the maximum number of unique sequence numbers from 64k down to 128. So it is a trade-off. The computation of a new IPC id is not done in the performance critical path. So a little bit of additional overhead shouldn't have any real performance impact. Link: http://lkml.kernel.org/r/20190329204930.21620-1-longman@redhat.comSigned-off-by:
-
Davidlohr Bueso authored
Our msg priorities became an rbtree as of d6629859 ("ipc/mqueue: improve performance of send/recv"). However, consuming a msg in msg_get() remains logarithmic (still being better than the case before of course). By applying well known techniques to cache pointers we can have the node with the highest priority in O(1), which is specially nice for the rt cases. Furthermore, some callers can call msg_get() in a loop. A new msg_tree_erase() helper is also added to encapsulate the tree removal and node_cache game. Passes ltp mq testcases. Link: http://lkml.kernel.org/r/20190321190216.1719-2-dave@stgolabs.netSigned-off-by:
Davidlohr Bueso <dbueso@suse.de> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by:
-
Davidlohr Bueso authored
We already store the current task fo the new waiter before calling wq_sleep() in both send and recv paths. Trivially remove the redundant assignment. Link: http://lkml.kernel.org/r/20190321190216.1719-1-dave@stgolabs.netSigned-off-by:
-
Li Rongqing authored
msgctl10 of ltp triggers the following lockup When CONFIG_KASAN is enabled on large memory SMP systems, the pages initialization can take a long time, if msgctl10 requests a huge block memory, and it will block rcu scheduler, so release cpu actively. After adding schedule() in free_msg, free_msg can not be called when holding spinlock, so adding msg to a tmp list, and free it out of spinlock rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-1 rcu_node (CPUs 16-31): P32505 rcu: Tasks blocked on level-1 rcu_node (CPUs 48-63): P34978 rcu: (detected by 11, t=35024 jiffies, g=44237529, q=16542267) msgctl10 R running task 21608 32505 2794 0x00000082 Call Trace: preempt_schedule_irq+0x4c/0xb0 retint_kernel+0x1b/0x2d RIP: 0010:__is_insn_slot_addr+0xfb/0x250 Code: 82 1d 00 48 8b 9b 90 00 00 00 4c 89 f7 49 c1 ee 03 e8 59 83 1d 00 48 b8 00 00 00 00 00 fc ff df 4c 39 eb 48 89 9d 58 ff ff ff <41> c6 04 06 f8 74 66 4c 8d 75 98 4c 89 f1 48 c1 e9 03 48 01 c8 48 RSP: 0018:ffff88bce041f758 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: dffffc0000000000 RBX: ffffffff8471bc50 RCX: ffffffff828a2a57 RDX: dffffc0000000000 RSI: dffffc0000000000 RDI: ffff88bce041f780 RBP: ffff88bce041f828 R08: ffffed15f3f4c5b3 R09: ffffed15f3f4c5b3 R10: 0000000000000001 R11: ffffed15f3f4c5b2 R12: 000000318aee9b73 R13: ffffffff8471bc50 R14: 1ffff1179c083ef0 R15: 1ffff1179c083eec kernel_text_address+0xc1/0x100 __kernel_text_address+0xe/0x30 unwind_get_return_address+0x2f/0x50 __save_stack_trace+0x92/0x100 create_object+0x380/0x650 __kmalloc+0x14c/0x2b0 load_msg+0x38/0x1a0 do_msgsnd+0x19e/0xcf0 do_syscall_64+0x117/0x400 entry_SYSCALL_64_after_hwframe+0x49/0xbe rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-1 rcu_node (CPUs 0-15): P32170 rcu: (detected by 14, t=35016 jiffies, g=44237525, q=12423063) msgctl10 R running task 21608 32170 32155 0x00000082 Call Trace: preempt_schedule_irq+0x4c/0xb0 retint_kernel+0x1b/0x2d RIP: 0010:lock_acquire+0x4d/0x340 Code: 48 81 ec c0 00 00 00 45 89 c6 4d 89 cf 48 8d 6c 24 20 48 89 3c 24 48 8d bb e4 0c 00 00 89 74 24 0c 48 c7 44 24 20 b3 8a b5 41 <48> c1 ed 03 48 c7 44 24 28 b4 25 18 84 48 c7 44 24 30 d0 54 7a 82 RSP: 0018:ffff88af83417738 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 RAX: dffffc0000000000 RBX: ffff88bd335f3080 RCX: 0000000000000002 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88bd335f3d64 RBP: ffff88af83417758 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: ffffed13f3f745b2 R12: 0000000000000000 R13: 0000000000000002 R14: 0000000000000000 R15: 0000000000000000 is_bpf_text_address+0x32/0xe0 kernel_text_address+0xec/0x100 __kernel_text_address+0xe/0x30 unwind_get_return_address+0x2f/0x50 __save_stack_trace+0x92/0x100 save_stack+0x32/0xb0 __kasan_slab_free+0x130/0x180 kfree+0xfa/0x2d0 free_msg+0x24/0x50 do_msgrcv+0x508/0xe60 do_syscall_64+0x117/0x400 entry_SYSCALL_64_after_hwframe+0x49/0xbe Davidlohr said: "So after releasing the lock, the msg rbtree/list is empty and new calls will not see those in the newly populated tmp_msg list, and therefore they cannot access the delayed msg freeing pointers, which is good. Also the fact that the node_cache is now freed before the actual messages seems to be harmless as this is wanted for msg_insert() avoiding GFP_ATOMIC allocations, and after releasing the info->lock the thing is freed anyway so it should not change things" Link: http://lkml.kernel.org/r/1552029161-4957-1-git-send-email-lirongqing@baidu.comSigned-off-by:
Li RongQing <lirongqing@baidu.com> Signed-off-by:
Zhang Yu <zhangyu31@baidu.com> Reviewed-by:
-
Leonard Crestez authored
The clk rate is always stored in clk_core but might be out of date and require calls to update from hardware. Deal with that case by printing a (c) suffix. Link: http://lkml.kernel.org/r/1a474318982a5f0125f2360c4161029b17f56bd1.1556881728.git.leonard.crestez@nxp.comSigned-off-by:
Leonard Crestez <leonard.crestez@nxp.com> Cc: Jan Kiszka <jan.kiszka@siemens.com> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Kieran Bingham <kbingham@kernel.org> Cc: Stephen Boyd <swboyd@chromium.org> Signed-off-by:
-
Leonard Crestez authored
An incorrect argument to list_for_each is an internal error in gdb scripts so a TypeError should be raised. The gdb.GdbError exception type is intended for user errors such as incorrect invocation. Drop the type assertion in list_for_each_entry because list_for_each isn't going to suddenly yield something else. Applies to both list and hlist Link: http://lkml.kernel.org/r/c1d3fd4db13d999a3ba57f5bbc1924862d824f61.1556881728.git.leonard.crestez@nxp.comSigned-off-by:
Stephen Boyd <sboyd@kernel.org> Cc: Jan Kiszka <jan.kiszka@siemens.com> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Kieran Bingham <kbingham@kernel.org> Signed-off-by:
-
Leonard Crestez authored
Finding an individual clk_core requires walking the tree which can be quite complicated so add a helper for easy access. (gdb) print *(struct clk_scu*)$lx_clk_core_lookup("uart0_clk")->hw Link: http://lkml.kernel.org/r/Message-ID: Signed-off-by: -
Leonard Crestez authored
Add an lx-clk-summary command which prints a subset of /sys/kernel/debug/clk/clk_summary. This can be used to examine hangs caused by clk not being enabled. Link: http://lkml.kernel.org/r/Message-ID: Signed-off-by:
-
Leonard Crestez authored
This allows easily examining kernel hlists in python. Link: http://lkml.kernel.org/r/Message-ID: Signed-off-by:
-
Stephen Boyd authored
These scripts have some pep8 style warnings. Fix them up so that this directory is all pep8 clean. Link: http://lkml.kernel.org/r/20190329220844.38234-6-swboyd@chromium.orgSigned-off-by:
Stephen Boyd <swboyd@chromium.org> Cc: Douglas Anderson <dianders@chromium.org> Cc: Nikolay Borisov <n.borisov.lkml@gmail.com> Cc: Kieran Bingham <kbingham@kernel.org> Cc: Jan Kiszka <jan.kiszka@siemens.com> Cc: Jackie Liu <liuyun01@kylinos.cn> Cc: Jason Wessel <jason.wessel@windriver.com> Signed-off-by:
-
Stephen Boyd authored
Implement a command to print the timer list, much like how /proc/timer_list is implemented. This can be used to look at the pending timers on a crashed system. [swboyd@chromium.org: v2] Link: http://lkml.kernel.org/r/20190329220844.38234-5-swboyd@chromium.org Link: http://lkml.kernel.org/r/20190325184522.260535-5-swboyd@chromium.orgSigned-off-by:
-
Stephen Boyd authored
Implement gdb functions for rb_first(), rb_last(), rb_next(), and rb_prev(). These can be useful to iterate through the kernel's red-black trees. [swboyd@chromium.org: v2] Link: http://lkml.kernel.org/r/20190329220844.38234-4-swboyd@chromium.org Link: http://lkml.kernel.org/r/20190325184522.260535-4-swboyd@chromium.orgSigned-off-by:
-
Stephen Boyd authored
lx-configdump <file> dumps the contents of the gzipped .config to a text file when the config is included in the kernel with CONFIG_IKCONFIG. By default, the file written is called config.txt, but it can be any user supplied filename as well. If the kernel config is in a module (configs.ko), then it can be loaded along with symbols for the module loaded with 'lx-symbols' and then this command will still work. Obviously if you have the whole vmlinux then this can also be achieved with scripts/extract-ikconfig, but this gdb script can be useful to confirm that the memory contents of the config in memory and the vmlinux contents on disk match what is expected. [swboyd@chromium.org: v2] Link: http://lkml.kernel.org/r/20190329220844.38234-3-swboyd@chromium.org Link: http://lkml.kernel.org/r/20190325184522.260535-3-swboyd@chromium.orgSigned-off-by:
-
Stephen Boyd authored
Patch series "gdb script for kconfig and timer list". This is a handful of changes to the kernel's gdb scripts to do some more debugging with kgdb. The first patch allows the vmlinux to be reloaded from where it was specified on the command line so that this set of scripts can be used from anywhere. The second patch adds a script to dump the config.gz to a file on the host debugging machine. The third patch adds some rb tree utilities and the last patch uses those rb tree walking utilities to dump out the contents of /proc/timer_list from a system under debug. This patch (of 5): If I run 'gdb <path/to/vmlinux>' and there's the vmlinux-gdb.py file there I can properly see symbols and use the lx commands provided by the GDB scripts. But once I run 'lx-symbols' at the command prompt, gdb reloads the vmlinux symbols assuming that this script was run from the directory that has vmlinux at the root. That isn't always true, but we could just look and see what symbols were already loaded and use that instead. Let's do that so this can work by being invoked anywhere. Link: http://lkml.kernel.org/r/20190325184522.260535-2-swboyd@chromium.orgSigned-off-by:
-
Tom Burkart authored
This patch implements the PPS ECHO functionality for pps-gpio, that sysfs claims is available already. Configuration is done via device tree bindings. No changes are made to userspace interfaces. This patch was originally written by Lukas Senger as part of a masters thesis project and modified for inclusion into the linux kernel by Tom Burkart. Link: http://lkml.kernel.org/r/20190324043305.6627-4-tom@aussec.comSigned-off-by:
Tom Burkart <tom@aussec.com> Acked-by:
Rodolfo Giometti <giometti@enneenne.com> Signed-off-by:
Lukas Senger <lukas@fridolin.com> Cc: Philipp Zabel <philipp.zabel@gmail.com> Cc: Rob Herring <robh@kernel.org> Signed-off-by:
-
Tom Burkart authored
This patch implements the device tree binding changes required for the PPS ECHO functionality for pps-gpio, that sysfs claims is available already. It adds two DT properties for configuring the PPS ECHO functionality. This patch is provided separated from the rest of the patch per Documentation/devicetree/bindings/submitting-patches.txt. This patch was originally written by Lukas Senger as part of a masters thesis project and modified for inclusion into the linux kernel by Tom Burkart. Link: http://lkml.kernel.org/r/20190324043305.6627-3-tom@aussec.comSigned-off-by:
Rob Herring <robh@kernel.org> Cc: Philipp Zabel <philipp.zabel@gmail.com> Signed-off-by:
-
Tom Burkart authored
This patch changes the GPIO access for the pps-gpio driver from the integer based API to the descriptor based API. The integer based API is considered deprecated and the descriptor based API is the preferred way to access GPIOs as per Documentation/driver-api/gpio/intro.rst No changes are made to userspace interfaces. Link: http://lkml.kernel.org/r/20190324043305.6627-2-tom@aussec.comSigned-off-by:
Philipp Zabel <philipp.zabel@gmail.com> Cc: Lukas Senger <lukas@fridolin.com> Cc: Rob Herring <robh@kernel.org> Signed-off-by:
-
Aaro Koskinen authored
Allow specifying reboot_mode for panic only. This is needed on systems where ramoops is used to store panic logs, and user wants to use warm reset to preserve those, while still having cold reset on normal reboots. Link: http://lkml.kernel.org/r/20190322004735.27702-1-aaro.koskinen@iki.fiSigned-off-by:
Aaro Koskinen <aaro.koskinen@nokia.com> Reviewed-by:
Kees Cook <keescook@chromium.org> Signed-off-by:
-
Feng Tang authored
When kernel panic happens, it will first print the panic call stack, then the ending msg like: [ 35.743249] ---[ end Kernel panic - not syncing: Fatal exception [ 35.749975] ------------[ cut here ]------------ The above message are very useful for debugging. But if system is configured to not reboot on panic, say the "panic_timeout" parameter equals 0, it will likely print out many noisy message like WARN() call stack for each and every CPU except the panic one, messages like below: WARNING: CPU: 1 PID: 280 at kernel/sched/core.c:1198 set_task_cpu+0x183/0x190 Call Trace: <IRQ> try_to_wake_up default_wake_function autoremove_wake_function __wake_up_common __wake_up_common_lock __wake_up wake_up_klogd_work_func irq_work_run_list irq_work_tick update_process_times tick_sched_timer __hrtimer_run_queues hrtimer_interrupt smp_apic_timer_interrupt apic_timer_interrupt For people working in console mode, the screen will first show the panic call stack, but immediately overridden by these noisy extra messages, which makes debugging much more difficult, as the original context gets lost on screen. Also these noisy messages will confuse some users, as I have seen many bug reporters posted the noisy message into bugzilla, instead of the real panic call stack and context. Adding a flag "suppress_printk" which gets set in panic() to avoid those noisy messages, without changing current kernel behavior that both panic blinking and sysrq magic key can work as is, suggested by Petr Mladek. To verify this, make sure kernel is not configured to reboot on panic and in console # echo c > /proc/sysrq-trigger to see if console only prints out the panic call stack. Link: http://lkml.kernel.org/r/1551430186-24169-1-git-send-email-feng.tang@intel.comSigned-off-by:
Feng Tang <feng.tang@intel.com> Suggested-by:
Petr Mladek <pmladek@suse.com> Reviewed-by:
Steven Rostedt (VMware) <rostedt@goodmis.org> Acked-by:
Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Kees Cook <keescook@chromium.org> Cc: Borislav Petkov <bp@suse.de> Cc: Andi Kleen <ak@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: Sasha Levin <sashal@kernel.org> Signed-off-by:
-
Greg Hackmann authored
LLVM uses profiling data that's deliberately similar to GCC, but has a very different way of exporting that data. LLVM calls llvm_gcov_init() once per module, and provides a couple of callbacks that we can use to ask for more data. We care about the "writeout" callback, which in turn calls back into compiler-rt/this module to dump all the gathered coverage data to disk: llvm_gcda_start_file() llvm_gcda_emit_function() llvm_gcda_emit_arcs() llvm_gcda_emit_function() llvm_gcda_emit_arcs() [... repeats for each function ...] llvm_gcda_summary_info() llvm_gcda_end_file() This design is much more stateless and unstructured than gcc's, and is intended to run at process exit. This forces us to keep some local state about which module we're dealing with at the moment. On the other hand, it also means we don't depend as much on how LLVM represents profiling data internally. See LLVM's lib/Transforms/Instrumentation/GCOVProfiling.cpp for more details on how this works, particularly GCOVProfiler::emitProfileArcs(), GCOVProfiler::insertCounterWriteout(), and GCOVProfiler::insertFlush(). [akpm@linux-foundation.org: coding-style fixes] Link: http://lkml.kernel.org/r/20190417225328.208129-1-trong@android.comSigned-off-by:Greg Hackmann <ghackmann@android.com> Signed-off-by:
Nick Desaulniers <ndesaulniers@google.com> Signed-off-by:
Tri Vo <trong@android.com> Co-developed-by:
Trilok Soni <tsoni@quicinc.com> Tested-by:
Prasad Sodagudi <psodagud@quicinc.com> Tested-by:
Daniel Mentz <danielmentz@google.com> Tested-by:
Petri Gynther <pgynther@google.com> Reviewed-by:
Peter Oberparleiter <oberpar@linux.ibm.com> Signed-off-by:
-
Tri Vo authored
Document some things of note to gcov users: 1. GCC gcov and Clang llvm-cov tools are not compatible. 2. The use of GCC vs Clang is transparent at build-time. Also adjust the documentation to account for the removal of config symbol CONFIG_GCOV_FORMAT_AUTODETECT by commit 6a61b70b ("gcov: remove CONFIG_GCOV_FORMAT_AUTODETECT"). Link: http://lkml.kernel.org/r/20190318025411.98014-4-trong@android.comSigned-off-by:
-
Greg Hackmann authored
Patch series "gcov: add Clang support", v4. This patch (of 3): base.c contains a few callbacks specific to GCC's gcov implementation. Move these into their own module in preparation for Clang support. Link: http://lkml.kernel.org/r/20190318025411.98014-2-trong@android.comSigned-off-by:
-
YueHaibing authored
Fix sparse warning: fs/eventfd.c:26:1: warning: symbol 'eventfd_ida' was not declared. Should it be static? Link: http://lkml.kernel.org/r/20190413142348.34716-1-yuehaibing@huawei.comSigned-off-by:
YueHaibing <yuehaibing@huawei.com> Signed-off-by:
-
Masatake YAMATO authored
Finding endpoints of an IPC channel is one of essential task to understand how a user program works. Procfs and netlink socket provide enough hints to find endpoints for IPC channels like pipes, unix sockets, and pseudo terminals. However, there is no simple way to find endpoints for an eventfd file from userland. An inode number doesn't hint. Unlike pipe, all eventfd files share the same inode object. To provide the way to find endpoints of an eventfd file, this patch adds "eventfd-id" field to /proc/PID/fdinfo of eventfd as identifier. Integers managed by an IDA are used as ids. A tool like lsof can utilize the information to print endpoints. Link: http://lkml.kernel.org/r/20190327181823.20222-1-yamato@redhat.comSigned-off-by:
Masatake YAMATO <yamato@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Kees Cook <keescook@chromium.org> Signed-off-by:
-
Timmy Li authored
Hash functions are not needed since idr is used now. Let's remove hash header file for cleanup. Link: http://lkml.kernel.org/r/20190430053319.95913-1-scuttimmy@gmail.comSigned-off-by:
Timmy Li <scuttimmy@gmail.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: KJ Tsanaktsidis <ktsanaktsidis@zendesk.com> Signed-off-by:
-
