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2020-12-15Merge tag 'net-next-5.11' of ↵Linus Torvalds1-0/+11
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next Pull networking updates from Jakub Kicinski: "Core: - support "prefer busy polling" NAPI operation mode, where we defer softirq for some time expecting applications to periodically busy poll - AF_XDP: improve efficiency by more batching and hindering the adjacency cache prefetcher - af_packet: make packet_fanout.arr size configurable up to 64K - tcp: optimize TCP zero copy receive in presence of partial or unaligned reads making zero copy a performance win for much smaller messages - XDP: add bulk APIs for returning / freeing frames - sched: support fragmenting IP packets as they come out of conntrack - net: allow virtual netdevs to forward UDP L4 and fraglist GSO skbs BPF: - BPF switch from crude rlimit-based to memcg-based memory accounting - BPF type format information for kernel modules and related tracing enhancements - BPF implement task local storage for BPF LSM - allow the FENTRY/FEXIT/RAW_TP tracing programs to use bpf_sk_storage Protocols: - mptcp: improve multiple xmit streams support, memory accounting and many smaller improvements - TLS: support CHACHA20-POLY1305 cipher - seg6: add support for SRv6 End.DT4/DT6 behavior - sctp: Implement RFC 6951: UDP Encapsulation of SCTP - ppp_generic: add ability to bridge channels directly - bridge: Connectivity Fault Management (CFM) support as is defined in IEEE 802.1Q section 12.14. Drivers: - mlx5: make use of the new auxiliary bus to organize the driver internals - mlx5: more accurate port TX timestamping support - mlxsw: - improve the efficiency of offloaded next hop updates by using the new nexthop object API - support blackhole nexthops - support IEEE 802.1ad (Q-in-Q) bridging - rtw88: major bluetooth co-existance improvements - iwlwifi: support new 6 GHz frequency band - ath11k: Fast Initial Link Setup (FILS) - mt7915: dual band concurrent (DBDC) support - net: ipa: add basic support for IPA v4.5 Refactor: - a few pieces of in_interrupt() cleanup work from Sebastian Andrzej Siewior - phy: add support for shared interrupts; get rid of multiple driver APIs and have the drivers write a full IRQ handler, slight growth of driver code should be compensated by the simpler API which also allows shared IRQs - add common code for handling netdev per-cpu counters - move TX packet re-allocation from Ethernet switch tag drivers to a central place - improve efficiency and rename nla_strlcpy - number of W=1 warning cleanups as we now catch those in a patchwork build bot Old code removal: - wan: delete the DLCI / SDLA drivers - wimax: move to staging - wifi: remove old WDS wifi bridging support" * tag 'net-next-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1922 commits) net: hns3: fix expression that is currently always true net: fix proc_fs init handling in af_packet and tls nfc: pn533: convert comma to semicolon af_vsock: Assign the vsock transport considering the vsock address flags af_vsock: Set VMADDR_FLAG_TO_HOST flag on the receive path vsock_addr: Check for supported flag values vm_sockets: Add VMADDR_FLAG_TO_HOST vsock flag vm_sockets: Add flags field in the vsock address data structure net: Disable NETIF_F_HW_TLS_TX when HW_CSUM is disabled tcp: Add logic to check for SYN w/ data in tcp_simple_retransmit net: mscc: ocelot: install MAC addresses in .ndo_set_rx_mode from process context nfc: s3fwrn5: Release the nfc firmware net: vxget: clean up sparse warnings mlxsw: spectrum_router: Use eXtended mezzanine to offload IPv4 router mlxsw: spectrum: Set KVH XLT cache mode for Spectrum2/3 mlxsw: spectrum_router_xm: Introduce basic XM cache flushing mlxsw: reg: Add Router LPM Cache Enable Register mlxsw: reg: Add Router LPM Cache ML Delete Register mlxsw: spectrum_router_xm: Implement L-value tracking for M-index mlxsw: reg: Add XM Router M Table Register ...
2020-11-25lockdep: Introduce in_softirq lockdep assertYunsheng Lin1-0/+11
The current semantic for napi_consume_skb() is that caller need to provide non-zero budget when calling from NAPI context, and breaking this semantic will cause hard to debug problem, because _kfree_skb_defer() need to run in atomic context in order to push the skb to the particular cpu' napi_alloc_cache atomically. So add the lockdep_assert_in_softirq() to assert when the running context is not in_softirq, in_softirq means softirq is serving or BH is disabled, which has a ambiguous semantics due to the BH disabled confusion, so add a comment to emphasize that. And the softirq context can be interrupted by hard IRQ or NMI context, lockdep_assert_in_softirq() need to assert about hard IRQ or NMI context too. Suggested-by: Jakub Kicinski <[email protected]> Signed-off-by: Yunsheng Lin <[email protected]> Signed-off-by: Jakub Kicinski <[email protected]>
2020-11-02lockdep: Provide dummy forward declaration of *_is_held() helpersJakub Kicinski1-0/+6
When CONFIG_LOCKDEP is not set, lock_is_held() and lockdep_is_held() are not declared or defined. This forces all callers to use #ifdefs around these checks. Recent RCU changes added a lot of lockdep_is_held() calls inside rcu_dereference_protected(). This macro hides its argument on !LOCKDEP builds, which can lead to false-positive unused-variable warnings. This commit therefore provides forward declarations of lock_is_held() and lockdep_is_held() but without defining them. This way callers (including those internal to RCU) can keep them visible to the compiler on !LOCKDEP builds and instead depend on dead code elimination to remove the references, which in turn prevents the linker from complaining about the lack of the corresponding function definitions. [ paulmck: Apply Peter Zijlstra feedback on "extern". ] Signed-off-by: Jakub Kicinski <[email protected]> -- CC: [email protected] CC: [email protected] CC: [email protected] Signed-off-by: Paul E. McKenney <[email protected]>
2020-10-09Merge branch 'locking/urgent' into locking/core, to pick up fixesIngo Molnar1-17/+12
Signed-off-by: Ingo Molnar <[email protected]>
2020-10-09lockdep: Revert "lockdep: Use raw_cpu_*() for per-cpu variables"Peter Zijlstra1-17/+9
The thinking in commit: fddf9055a60d ("lockdep: Use raw_cpu_*() for per-cpu variables") is flawed. While it is true that when we're migratable both CPUs will have a 0 value, it doesn't hold that when we do get migrated in the middle of a raw_cpu_op(), the old CPU will still have 0 by the time we get around to reading it on the new CPU. Luckily, the reason for that commit (s390 using preempt_disable() instead of preempt_disable_notrace() in their percpu code), has since been fixed by commit: 1196f12a2c96 ("s390: don't trace preemption in percpu macros") An audit of arch/*/include/asm/percpu*.h shows there are no other architectures affected by this particular issue. Fixes: fddf9055a60d ("lockdep: Use raw_cpu_*() for per-cpu variables") Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Signed-off-by: Ingo Molnar <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-10-09lockdep: Fix lockdep recursionPeter Zijlstra1-5/+8
Steve reported that lockdep_assert*irq*(), when nested inside lockdep itself, will trigger a false-positive. One example is the stack-trace code, as called from inside lockdep, triggering tracing, which in turn calls RCU, which then uses lockdep_assert_irqs_disabled(). Fixes: a21ee6055c30 ("lockdep: Change hardirq{s_enabled,_context} to per-cpu variables") Reported-by: Steven Rostedt <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Signed-off-by: Ingo Molnar <[email protected]>
2020-08-26lockdep: Extend __bfs() to work with multiple types of dependenciesBoqun Feng1-0/+2
Now we have four types of dependencies in the dependency graph, and not all the pathes carry real dependencies (the dependencies that may cause a deadlock), for example: Given lock A and B, if we have: CPU1 CPU2 ============= ============== write_lock(A); read_lock(B); read_lock(B); write_lock(A); (assuming read_lock(B) is a recursive reader) then we have dependencies A -(ER)-> B, and B -(SN)-> A, and a dependency path A -(ER)-> B -(SN)-> A. In lockdep w/o recursive locks, a dependency path from A to A means a deadlock. However, the above case is obviously not a deadlock, because no one holds B exclusively, therefore no one waits for the other to release B, so who get A first in CPU1 and CPU2 will run non-blockingly. As a result, dependency path A -(ER)-> B -(SN)-> A is not a real/strong dependency that could cause a deadlock. From the observation above, we know that for a dependency path to be real/strong, no two adjacent dependencies can be as -(*R)-> -(S*)->. Now our mission is to make __bfs() traverse only the strong dependency paths, which is simple: we record whether we only have -(*R)-> for the previous lock_list of the path in lock_list::only_xr, and when we pick a dependency in the traverse, we 1) filter out -(S*)-> dependency if the previous lock_list only has -(*R)-> dependency (i.e. ->only_xr is true) and 2) set the next lock_list::only_xr to true if we only have -(*R)-> left after we filter out dependencies based on 1), otherwise, set it to false. With this extension for __bfs(), we now need to initialize the root of __bfs() properly (with a correct ->only_xr), to do so, we introduce some helper functions, which also cleans up a little bit for the __bfs() root initialization code. Signed-off-by: Boqun Feng <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-08-26lockdep: Introduce lock_list::depBoqun Feng1-0/+2
To add recursive read locks into the dependency graph, we need to store the types of dependencies for the BFS later. There are four types of dependencies: * Exclusive -> Non-recursive dependencies: EN e.g. write_lock(prev) held and try to acquire write_lock(next) or non-recursive read_lock(next), which can be represented as "prev -(EN)-> next" * Shared -> Non-recursive dependencies: SN e.g. read_lock(prev) held and try to acquire write_lock(next) or non-recursive read_lock(next), which can be represented as "prev -(SN)-> next" * Exclusive -> Recursive dependencies: ER e.g. write_lock(prev) held and try to acquire recursive read_lock(next), which can be represented as "prev -(ER)-> next" * Shared -> Recursive dependencies: SR e.g. read_lock(prev) held and try to acquire recursive read_lock(next), which can be represented as "prev -(SR)-> next" So we use 4 bits for the presence of each type in lock_list::dep. Helper functions and macros are also introduced to convert a pair of locks into lock_list::dep bit and maintain the addition of different types of dependencies. Signed-off-by: Boqun Feng <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-08-26lockdep: Reduce the size of lock_list::distanceBoqun Feng1-1/+1
lock_list::distance is always not greater than MAX_LOCK_DEPTH (which is 48 right now), so a u16 will fit. This patch reduces the size of lock_list::distance to save space, so that we can introduce other fields to help detect recursive read lock deadlocks without increasing the size of lock_list structure. Suggested-by: Peter Zijlstra <[email protected]> Signed-off-by: Boqun Feng <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-08-26locking: More accurate annotations for read_lock()Boqun Feng1-1/+22
On the archs using QUEUED_RWLOCKS, read_lock() is not always a recursive read lock, actually it's only recursive if in_interrupt() is true. So change the annotation accordingly to catch more deadlocks. Note we used to treat read_lock() as pure recursive read locks in lib/locking-seftest.c, and this is useful, especially for the lockdep development selftest, so we keep this via a variable to force switching lock annotation for read_lock(). Signed-off-by: Boqun Feng <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-08-26lockdep: Use raw_cpu_*() for per-cpu variablesPeter Zijlstra1-5/+13
Sven reported that commit a21ee6055c30 ("lockdep: Change hardirq{s_enabled,_context} to per-cpu variables") caused trouble on s390 because their this_cpu_*() primitives disable preemption which then lands back tracing. On the one hand, per-cpu ops should use preempt_*able_notrace() and raw_local_irq_*(), on the other hand, we can trivialy use raw_cpu_*() ops for this. Fixes: a21ee6055c30 ("lockdep: Change hardirq{s_enabled,_context} to per-cpu variables") Reported-by: Sven Schnelle <[email protected]> Reviewed-by: Steven Rostedt (VMware) <[email protected]> Reviewed-by: Thomas Gleixner <[email protected]> Acked-by: Rafael J. Wysocki <[email protected]> Tested-by: Marco Elver <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-08-06locking/seqlock, headers: Untangle the spaghetti monsterPeter Zijlstra1-0/+1
By using lockdep_assert_*() from seqlock.h, the spaghetti monster attacked. Attack back by reducing seqlock.h dependencies from two key high level headers: - <linux/seqlock.h>: -Remove <linux/ww_mutex.h> - <linux/time.h>: -Remove <linux/seqlock.h> - <linux/sched.h>: +Add <linux/seqlock.h> The price was to add it to sched.h ... Core header fallout, we add direct header dependencies instead of gaining them parasitically from higher level headers: - <linux/dynamic_queue_limits.h>: +Add <asm/bug.h> - <linux/hrtimer.h>: +Add <linux/seqlock.h> - <linux/ktime.h>: +Add <asm/bug.h> - <linux/lockdep.h>: +Add <linux/smp.h> - <linux/sched.h>: +Add <linux/seqlock.h> - <linux/videodev2.h>: +Add <linux/kernel.h> Arch headers fallout: - PARISC: <asm/timex.h>: +Add <asm/special_insns.h> - SH: <asm/io.h>: +Add <asm/page.h> - SPARC: <asm/timer_64.h>: +Add <uapi/asm/asi.h> - SPARC: <asm/vvar.h>: +Add <asm/processor.h>, <asm/barrier.h> -Remove <linux/seqlock.h> - X86: <asm/fixmap.h>: +Add <asm/pgtable_types.h> -Remove <asm/acpi.h> There's also a bunch of parasitic header dependency fallout in .c files, not listed separately. [ mingo: Extended the changelog, split up & fixed the original patch. ] Co-developed-by: Ingo Molnar <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Signed-off-by: Ingo Molnar <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-07-29lockdep: Add preemption enabled/disabled assertion APIsAhmed S. Darwish1-0/+19
Asserting that preemption is enabled or disabled is a critical sanity check. Developers are usually reluctant to add such a check in a fastpath as reading the preemption count can be costly. Extend the lockdep API with macros asserting that preemption is disabled or enabled. If lockdep is disabled, or if the underlying architecture does not support kernel preemption, this assert has no runtime overhead. References: f54bb2ec02c8 ("locking/lockdep: Add IRQs disabled/enabled assertion APIs: ...") Signed-off-by: Ahmed S. Darwish <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-07-16lockdep: Move list.h inclusion into lockdep.hHerbert Xu1-0/+1
Currently lockdep_types.h includes list.h without actually using any of its macros or functions. All it needs are the type definitions which were moved into types.h long ago. This potentially causes inclusion loops because both are included by many core header files. This patch moves the list.h inclusion into lockdep.h. Note that we could probably remove it completely but that could potentially result in compile failures should any end users not include list.h directly and also be unlucky enough to not get list.h via some other header file. Reported-by: Petr Mladek <[email protected]> Signed-off-by: Herbert Xu <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Tested-by: Petr Mladek <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-07-10lockdep: Remove lockdep_hardirq{s_enabled,_context}() argumentPeter Zijlstra1-1/+1
Now that the macros use per-cpu data, we no longer need the argument. Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Reviewed-by: Ingo Molnar <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-07-10lockdep: Change hardirq{s_enabled,_context} to per-cpu variablesPeter Zijlstra1-16/+18
Currently all IRQ-tracking state is in task_struct, this means that task_struct needs to be defined before we use it. Especially for lockdep_assert_irq*() this can lead to header-hell. Move the hardirq state into per-cpu variables to avoid the task_struct dependency. Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Reviewed-by: Ingo Molnar <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-06-17lockdep: Split header file into lockdep and lockdep_typesHerbert Xu1-176/+2
There is a header file inclusion loop between asm-generic/bug.h and linux/kernel.h. This causes potential compile failurs depending on the which file is included first. One way of breaking this loop is to stop spinlock_types.h from including lockdep.h. This patch splits lockdep.h into two files for this purpose. Signed-off-by: Herbert Xu <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Reviewed-by: Sergey Senozhatsky <[email protected]> Reviewed-by: Andy Shevchenko <[email protected]> Acked-by: Petr Mladek <[email protected]> Acked-by: Steven Rostedt (VMware) <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-05-19lockdep: Always inline lockdep_{off,on}()Peter Zijlstra1-2/+21
These functions are called {early,late} in nmi_{enter,exit} and should not be traced or probed. They are also puny, so 'inline' them. Reported-by: Steven Rostedt <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-03-23completion: Use lockdep_assert_RT_in_threaded_ctx() in complete_all()Sebastian Siewior1-0/+15
The warning was intended to spot complete_all() users from hardirq context on PREEMPT_RT. The warning as-is will also trigger in interrupt handlers, which are threaded on PREEMPT_RT, which was not intended. Use lockdep_assert_RT_in_threaded_ctx() which triggers in non-preemptive context on PREEMPT_RT. Fixes: a5c6234e1028 ("completion: Use simple wait queues") Reported-by: kernel test robot <[email protected]> Suggested-by: Peter Zijlstra <[email protected]> Signed-off-by: Sebastian Andrzej Siewior <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-03-21lockdep: Introduce wait-type checksPeter Zijlstra1-11/+60
Extend lockdep to validate lock wait-type context. The current wait-types are: LD_WAIT_FREE, /* wait free, rcu etc.. */ LD_WAIT_SPIN, /* spin loops, raw_spinlock_t etc.. */ LD_WAIT_CONFIG, /* CONFIG_PREEMPT_LOCK, spinlock_t etc.. */ LD_WAIT_SLEEP, /* sleeping locks, mutex_t etc.. */ Where lockdep validates that the current lock (the one being acquired) fits in the current wait-context (as generated by the held stack). This ensures that there is no attempt to acquire mutexes while holding spinlocks, to acquire spinlocks while holding raw_spinlocks and so on. In other words, its a more fancy might_sleep(). Obviously RCU made the entire ordeal more complex than a simple single value test because RCU can be acquired in (pretty much) any context and while it presents a context to nested locks it is not the same as it got acquired in. Therefore its necessary to split the wait_type into two values, one representing the acquire (outer) and one representing the nested context (inner). For most 'normal' locks these two are the same. [ To make static initialization easier we have the rule that: .outer == INV means .outer == .inner; because INV == 0. ] It further means that its required to find the minimal .inner of the held stack to compare against the outer of the new lock; because while 'normal' RCU presents a CONFIG type to nested locks, if it is taken while already holding a SPIN type it obviously doesn't relax the rules. Below is an example output generated by the trivial test code: raw_spin_lock(&foo); spin_lock(&bar); spin_unlock(&bar); raw_spin_unlock(&foo); [ BUG: Invalid wait context ] ----------------------------- swapper/0/1 is trying to lock: ffffc90000013f20 (&bar){....}-{3:3}, at: kernel_init+0xdb/0x187 other info that might help us debug this: 1 lock held by swapper/0/1: #0: ffffc90000013ee0 (&foo){+.+.}-{2:2}, at: kernel_init+0xd1/0x187 The way to read it is to look at the new -{n,m} part in the lock description; -{3:3} for the attempted lock, and try and match that up to the held locks, which in this case is the one: -{2,2}. This tells that the acquiring lock requires a more relaxed environment than presented by the lock stack. Currently only the normal locks and RCU are converted, the rest of the lockdep users defaults to .inner = INV which is ignored. More conversions can be done when desired. The check for spinlock_t nesting is not enabled by default. It's a separate config option for now as there are known problems which are currently addressed. The config option allows to identify these problems and to verify that the solutions found are indeed solving them. The config switch will be removed and the checks will permanently enabled once the vast majority of issues has been addressed. [ bigeasy: Move LD_WAIT_FREE,… out of CONFIG_LOCKDEP to avoid compile failure with CONFIG_DEBUG_SPINLOCK + !CONFIG_LOCKDEP] [ tglx: Add the config option ] Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Signed-off-by: Sebastian Andrzej Siewior <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2019-12-11Merge drm/drm-next into drm-intel-next-queuedJani Nikula1-12/+11
Sync up with v5.5-rc1 to get the updated lock_release() API among other things. Fix the conflict reported by Stephen Rothwell [1]. [1] http://lore.kernel.org/r/[email protected] Signed-off-by: Jani Nikula <[email protected]>
2019-11-07lockdep: add might_lock_nested()Daniel Vetter1-0/+8
Necessary to annotate functions where we might acquire a mutex_lock_nested() or similar. Needed by i915. Acked-by: Peter Zijlstra (Intel) <[email protected]> Signed-off-by: Daniel Vetter <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Will Deacon <[email protected]> Cc: [email protected] Signed-off-by: Daniel Vetter <[email protected]> Signed-off-by: Maarten Lankhorst <[email protected]> Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
2019-10-09locking/lockdep: Remove unused @nested argument from lock_release()Qian Cai1-11/+10
Since the following commit: b4adfe8e05f1 ("locking/lockdep: Remove unused argument in __lock_release") @nested is no longer used in lock_release(), so remove it from all lock_release() calls and friends. Signed-off-by: Qian Cai <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Acked-by: Will Deacon <[email protected]> Acked-by: Daniel Vetter <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[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] 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] 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] Cc: [email protected] Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2019-07-25locking/lockdep: Reduce space occupied by stack tracesBart Van Assche1-6/+3
Although commit 669de8bda87b ("kernel/workqueue: Use dynamic lockdep keys for workqueues") unregisters dynamic lockdep keys when a workqueue is destroyed, a side effect of that commit is that all stack traces associated with the lockdep key are leaked when a workqueue is destroyed. Fix this by storing each unique stack trace once. Other changes in this patch are: - Use NULL instead of { .nr_entries = 0 } to represent 'no trace'. - Store a pointer to a stack trace in struct lock_class and struct lock_list instead of storing 'nr_entries' and 'offset'. This patch avoids that the following program triggers the "BUG: MAX_STACK_TRACE_ENTRIES too low!" complaint: #include <fcntl.h> #include <unistd.h> int main() { for (;;) { int fd = open("/dev/infiniband/rdma_cm", O_RDWR); close(fd); } } Suggested-by: Peter Zijlstra <[email protected]> Reported-by: Eric Biggers <[email protected]> Signed-off-by: Bart Van Assche <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Waiman Long <[email protected]> Cc: Will Deacon <[email protected]> Cc: Yuyang Du <[email protected]> Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2019-07-25locking/lockdep: Make it clear that what lock_class::key points at is not ↵Bart Van Assche1-1/+1
modified This patch does not change the behavior of the lockdep code. Signed-off-by: Bart Van Assche <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Waiman Long <[email protected]> Cc: Will Deacon <[email protected]> Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2019-07-15docs: locking: convert docs to ReST and rename to *.rstMauro Carvalho Chehab1-1/+1
Convert the locking documents to ReST and add them to the kernel development book where it belongs. Most of the stuff here is just to make Sphinx to properly parse the text file, as they're already in good shape, not requiring massive changes in order to be parsed. The conversion is actually: - add blank lines and identation in order to identify paragraphs; - fix tables markups; - add some lists markups; - mark literal blocks; - adjust title markups. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <[email protected]> Acked-by: Federico Vaga <[email protected]>
2019-07-08Merge branch 'locking-core-for-linus' of ↵Linus Torvalds1-12/+24
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking updates from Ingo Molnar: "The main changes in this cycle are: - rwsem scalability improvements, phase #2, by Waiman Long, which are rather impressive: "On a 2-socket 40-core 80-thread Skylake system with 40 reader and writer locking threads, the min/mean/max locking operations done in a 5-second testing window before the patchset were: 40 readers, Iterations Min/Mean/Max = 1,807/1,808/1,810 40 writers, Iterations Min/Mean/Max = 1,807/50,344/151,255 After the patchset, they became: 40 readers, Iterations Min/Mean/Max = 30,057/31,359/32,741 40 writers, Iterations Min/Mean/Max = 94,466/95,845/97,098" There's a lot of changes to the locking implementation that makes it similar to qrwlock, including owner handoff for more fair locking. Another microbenchmark shows how across the spectrum the improvements are: "With a locking microbenchmark running on 5.1 based kernel, the total locking rates (in kops/s) on a 2-socket Skylake system with equal numbers of readers and writers (mixed) before and after this patchset were: # of Threads Before Patch After Patch ------------ ------------ ----------- 2 2,618 4,193 4 1,202 3,726 8 802 3,622 16 729 3,359 32 319 2,826 64 102 2,744" The changes are extensive and the patch-set has been through several iterations addressing various locking workloads. There might be more regressions, but unless they are pathological I believe we want to use this new implementation as the baseline going forward. - jump-label optimizations by Daniel Bristot de Oliveira: the primary motivation was to remove IPI disturbance of isolated RT-workload CPUs, which resulted in the implementation of batched jump-label updates. Beyond the improvement of the real-time characteristics kernel, in one test this patchset improved static key update overhead from 57 msecs to just 1.4 msecs - which is a nice speedup as well. - atomic64_t cross-arch type cleanups by Mark Rutland: over the last ~10 years of atomic64_t existence the various types used by the APIs only had to be self-consistent within each architecture - which means they became wildly inconsistent across architectures. Mark puts and end to this by reworking all the atomic64 implementations to use 's64' as the base type for atomic64_t, and to ensure that this type is consistently used for parameters and return values in the API, avoiding further problems in this area. - A large set of small improvements to lockdep by Yuyang Du: type cleanups, output cleanups, function return type and othr cleanups all around the place. - A set of percpu ops cleanups and fixes by Peter Zijlstra. - Misc other changes - please see the Git log for more details" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (82 commits) locking/lockdep: increase size of counters for lockdep statistics locking/atomics: Use sed(1) instead of non-standard head(1) option locking/lockdep: Move mark_lock() inside CONFIG_TRACE_IRQFLAGS && CONFIG_PROVE_LOCKING x86/jump_label: Make tp_vec_nr static x86/percpu: Optimize raw_cpu_xchg() x86/percpu, sched/fair: Avoid local_clock() x86/percpu, x86/irq: Relax {set,get}_irq_regs() x86/percpu: Relax smp_processor_id() x86/percpu: Differentiate this_cpu_{}() and __this_cpu_{}() locking/rwsem: Guard against making count negative locking/rwsem: Adaptive disabling of reader optimistic spinning locking/rwsem: Enable time-based spinning on reader-owned rwsem locking/rwsem: Make rwsem->owner an atomic_long_t locking/rwsem: Enable readers spinning on writer locking/rwsem: Clarify usage of owner's nonspinaable bit locking/rwsem: Wake up almost all readers in wait queue locking/rwsem: More optimal RT task handling of null owner locking/rwsem: Always release wait_lock before waking up tasks locking/rwsem: Implement lock handoff to prevent lock starvation locking/rwsem: Make rwsem_spin_on_owner() return owner state ...
2019-06-17locking/lockdep: Rename lockdep_assert_held_exclusive() -> ↵Nikolay Borisov1-2/+2
lockdep_assert_held_write() All callers of lockdep_assert_held_exclusive() use it to verify the correct locking state of either a semaphore (ldisc_sem in tty, mmap_sem for perf events, i_rwsem of inode for dax) or rwlock by apparmor. Thus it makes sense to rename _exclusive to _write since that's the semantics callers care. Additionally there is already lockdep_assert_held_read(), which this new naming is more consistent with. No functional changes. Signed-off-by: Nikolay Borisov <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2019-06-03locking/lockdep: Change the range of class_idx in held_lock structYuyang Du1-7/+7
held_lock->class_idx is used to point to the class of the held lock. The index is shifted by 1 to make index 0 mean no class, which results in class index shifting back and forth but is not worth doing so. The reason is: (1) there will be no "no-class" held_lock to begin with, and (2) index 0 seems to be used for error checking, but if something wrong indeed happened, the index can't be counted on to distinguish it as that something won't set the class_idx to 0 on purpose to tell us it is wrong. Therefore, change the index to start from 0. This saves a lot of back-and-forth shifts and a class slot back to lock_classes. Since index 0 is now used for lock class, we change the initial chain key to -1 to avoid key collision, which is due to the fact that __jhash_mix(0, 0, 0) = 0. Actually, the initial chain key can be any arbitrary value other than 0. In addition, a bitmap is maintained to keep track of the used lock classes, and we check the validity of the held lock against that bitmap. Signed-off-by: Yuyang Du <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2019-06-03locking/lockdep: Define INITIAL_CHAIN_KEY for chain keys to start withYuyang Du1-0/+1
Chain keys are computed using Jenkins hash function, which needs an initial hash to start with. Dedicate a macro to make this clear and configurable. A later patch changes this initial chain key. Signed-off-by: Yuyang Du <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2019-06-03locking/lockdep: Use lockdep_init_task for task initiation consistentlyYuyang Du1-1/+6
Despite that there is a lockdep_init_task() which does nothing, lockdep initiates tasks by assigning lockdep fields and does so inconsistently. Fix this by using lockdep_init_task(). Signed-off-by: Yuyang Du <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2019-06-03locking/lockdep: Update obsolete struct field descriptionYuyang Du1-3/+9
The lock_chain struct definition has outdated comment, update it and add struct member description. Signed-off-by: Yuyang Du <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2019-05-25lockdep: Add assertion to check if in an interruptJoel Fernandes (Google)1-0/+7
In rcu_rrupt_from_idle, we want to check if it is called from within an interrupt, but want to do such checking only for debug builds. lockdep already tracks when we enter an interrupt. Let us expose it as an assertion macro so it can be used to assert this. Suggested-by: Steven Rostedt <[email protected]> Cc: [email protected] Cc: [email protected] Signed-off-by: Joel Fernandes (Google) <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]>
2019-05-06Merge branch 'locking-core-for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking updates from Ingo Molnar: "Here are the locking changes in this cycle: - rwsem unification and simpler micro-optimizations to prepare for more intrusive (and more lucrative) scalability improvements in v5.3 (Waiman Long) - Lockdep irq state tracking flag usage cleanups (Frederic Weisbecker) - static key improvements (Jakub Kicinski, Peter Zijlstra) - misc updates, cleanups and smaller fixes" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (26 commits) locking/lockdep: Remove unnecessary unlikely() locking/static_key: Don't take sleeping locks in __static_key_slow_dec_deferred() locking/static_key: Factor out the fast path of static_key_slow_dec() locking/static_key: Add support for deferred static branches locking/lockdep: Test all incompatible scenarios at once in check_irq_usage() locking/lockdep: Avoid bogus Clang warning locking/lockdep: Generate LOCKF_ bit composites locking/lockdep: Use expanded masks on find_usage_*() functions locking/lockdep: Map remaining magic numbers to lock usage mask names locking/lockdep: Move valid_state() inside CONFIG_TRACE_IRQFLAGS && CONFIG_PROVE_LOCKING locking/rwsem: Prevent unneeded warning during locking selftest locking/rwsem: Optimize rwsem structure for uncontended lock acquisition locking/rwsem: Enable lock event counting locking/lock_events: Don't show pvqspinlock events on bare metal locking/lock_events: Make lock_events available for all archs & other locks locking/qspinlock_stat: Introduce generic lockevent_*() counting APIs locking/rwsem: Enhance DEBUG_RWSEMS_WARN_ON() macro locking/rwsem: Add debug check for __down_read*() locking/rwsem: Micro-optimize rwsem_try_read_lock_unqueued() locking/rwsem: Move rwsem internal function declarations to rwsem-xadd.h ...
2019-04-29lockdep: Simplify stack trace handlingThomas Gleixner1-2/+7
Replace the indirection through struct stack_trace by using the storage array based interfaces and storing the information is a small lockdep specific data structure. Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Josh Poimboeuf <[email protected]> Acked-by: Peter Zijlstra (Intel) <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: Alexander Potapenko <[email protected]> Cc: Alexey Dobriyan <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Christoph Lameter <[email protected]> Cc: Pekka Enberg <[email protected]> Cc: [email protected] Cc: David Rientjes <[email protected]> Cc: Catalin Marinas <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Andrey Ryabinin <[email protected]> Cc: [email protected] Cc: Mike Rapoport <[email protected]> Cc: Akinobu Mita <[email protected]> Cc: Christoph Hellwig <[email protected]> Cc: [email protected] Cc: Robin Murphy <[email protected]> Cc: Marek Szyprowski <[email protected]> Cc: Johannes Thumshirn <[email protected]> Cc: David Sterba <[email protected]> Cc: Chris Mason <[email protected]> Cc: Josef Bacik <[email protected]> Cc: [email protected] Cc: [email protected] Cc: Mike Snitzer <[email protected]> Cc: Alasdair Kergon <[email protected]> Cc: Daniel Vetter <[email protected]> Cc: [email protected] Cc: Joonas Lahtinen <[email protected]> Cc: Maarten Lankhorst <[email protected]> Cc: [email protected] Cc: David Airlie <[email protected]> Cc: Jani Nikula <[email protected]> Cc: Rodrigo Vivi <[email protected]> Cc: Tom Zanussi <[email protected]> Cc: Miroslav Benes <[email protected]> Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected]
2019-04-18locking/lockdep: Avoid bogus Clang warningArnd Bergmann1-1/+1
When lockdep is enabled, and -Wuninitialized warnings are enabled, Clang produces a silly warning for every file we compile: In file included from kernel/sched/fair.c:23: kernel/sched/sched.h:1094:15: error: variable 'cookie' is uninitialized when used here [-Werror,-Wuninitialized] rf->cookie = lockdep_pin_lock(&rq->lock); ^~~~~~~~~~~~~~~~~~~~~~~~~~~ include/linux/lockdep.h:474:60: note: expanded from macro 'lockdep_pin_lock' #define lockdep_pin_lock(l) ({ struct pin_cookie cookie; cookie; }) ^~~~~~ kernel/sched/sched.h:1094:15: note: variable 'cookie' is declared here include/linux/lockdep.h:474:34: note: expanded from macro 'lockdep_pin_lock' #define lockdep_pin_lock(l) ({ struct pin_cookie cookie; cookie; }) ^ As the 'struct pin_cookie' structure is empty in this configuration, there is no need to initialize it for correctness, but it also does not hurt to set it to an empty structure, so do that to avoid the warning. Signed-off-by: Arnd Bergmann <[email protected]> Acked-by: Will Deacon <[email protected]> Cc: Bart Van Assche <[email protected]> Cc: Joel Fernandes (Google) <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Nathan Chancellor <[email protected]> Cc: Nick Desaulniers <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Steven Rostedt (VMware) <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Waiman Long <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2019-02-28locking/lockdep: Shrink struct lock_class_keyPeter Zijlstra1-2/+4
Shrink struct lock_class_key; we never store anything in subkeys[], we only use the addresses. Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Paul E. McKenney <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Will Deacon <[email protected]> Signed-off-by: Ingo Molnar <[email protected]>
2019-02-28locking/lockdep: Add support for dynamic keysBart Van Assche1-3/+18
A shortcoming of the current lockdep implementation is that it requires lock keys to be allocated statically. That forces all instances of lock objects that occur in a given data structure to share a lock key. Since lock dependency analysis groups lock objects per key sharing lock keys can cause false positive lockdep reports. Make it possible to avoid such false positive reports by allowing lock keys to be allocated dynamically. Require that dynamically allocated lock keys are registered before use by calling lockdep_register_key(). Complain about attempts to register the same lock key pointer twice without calling lockdep_unregister_key() between successive registration calls. The purpose of the new lock_keys_hash[] data structure that keeps track of all dynamic keys is twofold: - Verify whether the lockdep_register_key() and lockdep_unregister_key() functions are used correctly. - Avoid that lockdep_init_map() complains when encountering a dynamically allocated key. Signed-off-by: Bart Van Assche <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Johannes Berg <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Paul E. McKenney <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Waiman Long <[email protected]> Cc: Will Deacon <[email protected]> Cc: [email protected] Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2019-02-28locking/lockdep: Free lock classes that are no longer in useBart Van Assche1-3/+6
Instead of leaving lock classes that are no longer in use in the lock_classes array, reuse entries from that array that are no longer in use. Maintain a linked list of free lock classes with list head 'free_lock_class'. Only add freed lock classes to the free_lock_classes list after a grace period to avoid that a lock_classes[] element would be reused while an RCU reader is accessing it. Since the lockdep selftests run in a context where sleeping is not allowed and since the selftests require that lock resetting/zapping works with debug_locks off, make the behavior of lockdep_free_key_range() and lockdep_reset_lock() depend on whether or not these are called from the context of the lockdep selftests. Thanks to Peter for having shown how to modify get_pending_free() such that that function does not have to sleep. Signed-off-by: Bart Van Assche <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Johannes Berg <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Paul E. McKenney <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Waiman Long <[email protected]> Cc: Will Deacon <[email protected]> Cc: [email protected] Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2019-02-28locking/lockdep: Make it easy to detect whether or not inside a selftestBart Van Assche1-0/+5
The patch that frees unused lock classes will modify the behavior of lockdep_free_key_range() and lockdep_reset_lock() depending on whether or not these functions are called from the context of the lockdep selftests. Hence make it easy to detect whether or not lockdep code is called from the context of a lockdep selftest. Signed-off-by: Bart Van Assche <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Johannes Berg <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Paul E. McKenney <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Waiman Long <[email protected]> Cc: Will Deacon <[email protected]> Cc: [email protected] Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2019-02-28locking/lockdep: Make zap_class() remove all matching lock order entriesBart Van Assche1-0/+1
Make sure that all lock order entries that refer to a class are removed from the list_entries[] array when a kernel module is unloaded. Signed-off-by: Bart Van Assche <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Johannes Berg <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Paul E. McKenney <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Waiman Long <[email protected]> Cc: Will Deacon <[email protected]> Cc: [email protected] Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2019-02-28locking/lockdep: Reorder struct lock_class membersBart Van Assche1-7/+7
This patch does not change any functionality but makes the patch that frees lock classes that are no longer in use easier to read. Signed-off-by: Bart Van Assche <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Johannes Berg <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Paul E. McKenney <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Waiman Long <[email protected]> Cc: Will Deacon <[email protected]> Cc: [email protected] Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2018-12-11locking/lockdep: Remove ::version from lock_class structureWaiman Long1-2/+0
It turns out the version field in the lock_class structure isn't used anywhere. Just remove it. Signed-off-by: Waiman Long <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Andrey Ryabinin <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Petr Mladek <[email protected]> Cc: Sasha Levin <[email protected]> Cc: Sergey Senozhatsky <[email protected]> Cc: Tejun Heo <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Will Deacon <[email protected]> Cc: [email protected] Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2018-10-09locking/lockdep: Make class->ops a percpu counter and move it under ↵Waiman Long1-6/+1
CONFIG_DEBUG_LOCKDEP=y A sizable portion of the CPU cycles spent on the __lock_acquire() is used up by the atomic increment of the class->ops stat counter. By taking it out from the lock_class structure and changing it to a per-cpu per-lock-class counter, we can reduce the amount of cacheline contention on the class structure when multiple CPUs are trying to acquire locks of the same class simultaneously. To limit the increase in memory consumption because of the percpu nature of that counter, it is now put back under the CONFIG_DEBUG_LOCKDEP config option. So the memory consumption increase will only occur if CONFIG_DEBUG_LOCKDEP is defined. The lock_class structure, however, is reduced in size by 16 bytes on 64-bit archs after ops removal and a minor restructuring of the fields. This patch also fixes a bug in the increment code as the counter is of the 'unsigned long' type, but atomic_inc() was used to increment it. Signed-off-by: Waiman Long <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Will Deacon <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2018-08-10tracing: Partial revert of "tracing: Centralize preemptirq tracepoints and ↵Steven Rostedt (VMware)1-2/+0
unify their usage" Joel Fernandes created a nice patch that cleaned up the duplicate hooks used by lockdep and irqsoff latency tracer. It made both use tracepoints. But it caused lockdep to trigger several false positives. We have not figured out why yet, but removing lockdep from using the trace event hooks and just call its helper functions directly (like it use to), makes the problem go away. This is a partial revert of the clean up patch c3bc8fd637a9 ("tracing: Centralize preemptirq tracepoints and unify their usage") that adds direct calls for lockdep, but also keeps most of the clean up done to get rid of the horrible preprocessor if statements. Link: http://lkml.kernel.org/r/[email protected] Cc: Peter Zijlstra <[email protected]> Reviewed-by: Joel Fernandes (Google) <[email protected]> Fixes: c3bc8fd637a9 ("tracing: Centralize preemptirq tracepoints and unify their usage") Signed-off-by: Steven Rostedt (VMware) <[email protected]>
2018-07-31tracing: Centralize preemptirq tracepoints and unify their usageJoel Fernandes (Google)1-3/+5
This patch detaches the preemptirq tracepoints from the tracers and keeps it separate. Advantages: * Lockdep and irqsoff event can now run in parallel since they no longer have their own calls. * This unifies the usecase of adding hooks to an irqsoff and irqson event, and a preemptoff and preempton event. 3 users of the events exist: - Lockdep - irqsoff and preemptoff tracers - irqs and preempt trace events The unification cleans up several ifdefs and makes the code in preempt tracer and irqsoff tracers simpler. It gets rid of all the horrific ifdeferry around PROVE_LOCKING and makes configuration of the different users of the tracepoints more easy and understandable. It also gets rid of the time_* function calls from the lockdep hooks used to call into the preemptirq tracer which is not needed anymore. The negative delta in lines of code in this patch is quite large too. In the patch we introduce a new CONFIG option PREEMPTIRQ_TRACEPOINTS as a single point for registering probes onto the tracepoints. With this, the web of config options for preempt/irq toggle tracepoints and its users becomes: PREEMPT_TRACER PREEMPTIRQ_EVENTS IRQSOFF_TRACER PROVE_LOCKING | | \ | | \ (selects) / \ \ (selects) / TRACE_PREEMPT_TOGGLE ----> TRACE_IRQFLAGS \ / \ (depends on) / PREEMPTIRQ_TRACEPOINTS Other than the performance tests mentioned in the previous patch, I also ran the locking API test suite. I verified that all tests cases are passing. I also injected issues by not registering lockdep probes onto the tracepoints and I see failures to confirm that the probes are indeed working. This series + lockdep probes not registered (just to inject errors): [ 0.000000] hard-irqs-on + irq-safe-A/21: ok | ok | ok | [ 0.000000] soft-irqs-on + irq-safe-A/21: ok | ok | ok | [ 0.000000] sirq-safe-A => hirqs-on/12:FAILED|FAILED| ok | [ 0.000000] sirq-safe-A => hirqs-on/21:FAILED|FAILED| ok | [ 0.000000] hard-safe-A + irqs-on/12:FAILED|FAILED| ok | [ 0.000000] soft-safe-A + irqs-on/12:FAILED|FAILED| ok | [ 0.000000] hard-safe-A + irqs-on/21:FAILED|FAILED| ok | [ 0.000000] soft-safe-A + irqs-on/21:FAILED|FAILED| ok | [ 0.000000] hard-safe-A + unsafe-B #1/123: ok | ok | ok | [ 0.000000] soft-safe-A + unsafe-B #1/123: ok | ok | ok | With this series + lockdep probes registered, all locking tests pass: [ 0.000000] hard-irqs-on + irq-safe-A/21: ok | ok | ok | [ 0.000000] soft-irqs-on + irq-safe-A/21: ok | ok | ok | [ 0.000000] sirq-safe-A => hirqs-on/12: ok | ok | ok | [ 0.000000] sirq-safe-A => hirqs-on/21: ok | ok | ok | [ 0.000000] hard-safe-A + irqs-on/12: ok | ok | ok | [ 0.000000] soft-safe-A + irqs-on/12: ok | ok | ok | [ 0.000000] hard-safe-A + irqs-on/21: ok | ok | ok | [ 0.000000] soft-safe-A + irqs-on/21: ok | ok | ok | [ 0.000000] hard-safe-A + unsafe-B #1/123: ok | ok | ok | [ 0.000000] soft-safe-A + unsafe-B #1/123: ok | ok | ok | Link: http://lkml.kernel.org/r/[email protected] Acked-by: Peter Zijlstra (Intel) <[email protected]> Reviewed-by: Namhyung Kim <[email protected]> Signed-off-by: Joel Fernandes (Google) <[email protected]> Signed-off-by: Steven Rostedt (VMware) <[email protected]>
2018-01-30Merge branch 'locking-core-for-linus' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking updates from Ingo Molnar: "The main changes relate to making lock_is_held() et al (and external wrappers of them) work on const data types - this requires const propagation through the depths of lockdep. This removes a number of ugly type hacks the external helpers used" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: lockdep: Convert some users to const lockdep: Make lockdep checking constant lockdep: Assign lock keys on registration
2018-01-29Merge tag 'init_task-20180117' of ↵Linus Torvalds1-3/+0
git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs Pull init_task initializer cleanups from David Howells: "It doesn't seem useful to have the init_task in a header file rather than in a normal source file. We could consolidate init_task handling instead and expand out various macros. Here's a series of patches that consolidate init_task handling: (1) Make THREAD_SIZE available to vmlinux.lds for cris, hexagon and openrisc. (2) Alter the INIT_TASK_DATA linker script macro to set init_thread_union and init_stack rather than defining these in C. Insert init_task and init_thread_into into the init_stack area in the linker script as appropriate to the configuration, with different section markers so that they end up correctly ordered. We can then get merge ia64's init_task.c into the main one. We then have a bunch of single-use INIT_*() macros that seem only to be macros because they used to be used per-arch. We can then expand these in place of the user and get rid of a few lines and a lot of backslashes. (3) Expand INIT_TASK() in place. (4) Expand in place various small INIT_*() macros that are defined conditionally. Expand them and surround them by #if[n]def/#endif in the .c file as it takes fewer lines. (5) Expand INIT_SIGNALS() and INIT_SIGHAND() in place. (6) Expand INIT_STRUCT_PID in place. These macros can then be discarded" * tag 'init_task-20180117' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: Expand INIT_STRUCT_PID and remove Expand the INIT_SIGNALS and INIT_SIGHAND macros and remove Expand various INIT_* macros and remove Expand INIT_TASK() in init/init_task.c and remove Construct init thread stack in the linker script rather than by union openrisc: Make THREAD_SIZE available to vmlinux.lds hexagon: Make THREAD_SIZE available to vmlinux.lds cris: Make THREAD_SIZE available to vmlinux.lds
2018-01-18lockdep: Make lockdep checking constantMatthew Wilcox1-2/+2
There are several places in the kernel which would like to pass a const pointer to lockdep_is_held(). Constify the entire path so nobody has to trick the compiler. Signed-off-by: Matthew Wilcox <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Acked-by: Peter Zijlstra (Intel) <[email protected]> Cc: "David S. Miller" <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2018-01-17Expand various INIT_* macros and removeDavid Howells1-3/+0
Expand various INIT_* macros into the single places they're used in init/init_task.c and remove them. Signed-off-by: David Howells <[email protected]> Tested-by: Tony Luck <[email protected]> Tested-by: Will Deacon <[email protected]> (arm64) Tested-by: Palmer Dabbelt <[email protected]> Acked-by: Thomas Gleixner <[email protected]>
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