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2017-06-08rcu: Add memory barriers for NOCB leader wakeupPaul E. McKenney
Wait/wakeup operations do not guarantee ordering on their own. Instead, either locking or memory barriers are required. This commit therefore adds memory barriers to wake_nocb_leader() and nocb_leader_wait(). Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Tested-by: Krister Johansen <kjlx@templeofstupid.com> Cc: <stable@vger.kernel.org> # 4.6.x
2017-06-08Merge tag 'pm-4.12-rc5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management fixes from Rafael Wysocki: "These revert one problematic commit related to system sleep and fix one recent intel_pstate regression. Specifics: - Revert a recent commit that attempted to avoid spurious wakeups from suspend-to-idle via ACPI SCI, but introduced regressions on some systems (Rafael Wysocki). We will get back to the problem it tried to address in the next cycle. - Fix a possible division by 0 during intel_pstate initialization due to a missing check (Rafael Wysocki)" * tag 'pm-4.12-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: Revert "ACPI / sleep: Ignore spurious SCI wakeups from suspend-to-idle" cpufreq: intel_pstate: Avoid division by 0 in min_perf_pct_min()
2017-06-08Merge tag 'modules-for-v4.12-rc5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux Pull module maintainer address change from Jessica Yu: "A single patch that advertises my email address change" * tag 'modules-for-v4.12-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux: MAINTAINERS: update email address for Jessica Yu
2017-06-08net: vrf: Make add_fib_rules per network namespace flagDavid Ahern
Commit 1aa6c4f6b8cd8 ("net: vrf: Add l3mdev rules on first device create") adds the l3mdev FIB rule the first time a VRF device is created. However, it only creates the rule once and only in the namespace the first device is created - which may not be init_net. Fix by using the net_generic capability to make the add_fib_rules flag per network namespace. Fixes: 1aa6c4f6b8cd8 ("net: vrf: Add l3mdev rules on first device create") Reported-by: Petr Machata <petrm@mellanox.com> Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-09Merge branches 'intel_pstate' and 'pm-sleep'Rafael J. Wysocki
* intel_pstate: cpufreq: intel_pstate: Avoid division by 0 in min_perf_pct_min() * pm-sleep: Revert "ACPI / sleep: Ignore spurious SCI wakeups from suspend-to-idle"
2017-06-09Merge tag 'perf-urgent-for-mingo-4.12-20170608' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent Pull perf/urgent fixes from Arnaldo Carvalho de Melo: - Fixes for handling compressed kernel modules (Namhyung Kim) - Fix handling old style build-id cache ($HOME/.debug/) (Namhyung Kim) - 'perf script' python/perl documentation fixes: outdated comments, invalid code snippets, etc (SeongJae Park) Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-08bpf, tests: fix endianness selectionDaniel Borkmann
I noticed that test_l4lb was failing in selftests: # ./test_progs test_pkt_access:PASS:ipv4 77 nsec test_pkt_access:PASS:ipv6 44 nsec test_xdp:PASS:ipv4 2933 nsec test_xdp:PASS:ipv6 1500 nsec test_l4lb:PASS:ipv4 377 nsec test_l4lb:PASS:ipv6 544 nsec test_l4lb:FAIL:stats 6297600000 200000 test_tcp_estats:PASS: 0 nsec Summary: 7 PASSED, 1 FAILED Tracking down the issue actually revealed that endianness selection in bpf_endian.h is broken when compiled with clang with bpf target. test_pkt_access.c, test_l4lb.c is compiled with __BYTE_ORDER as __BIG_ENDIAN, test_xdp.c as __LITTLE_ENDIAN! test_l4lb noticeably fails, because the test accounts bytes via bpf_ntohs(ip6h->payload_len) and bpf_ntohs(iph->tot_len), and compares them against a defined value and given a wrong endianness, the test outcome is different, of course. Turns out that there are actually two bugs: i) when we do __BYTE_ORDER comparison with __LITTLE_ENDIAN/__BIG_ENDIAN, then depending on the include order we see different outcomes. Reason is that __BYTE_ORDER is undefined due to missing endian.h include. Before we include the asm/byteorder.h (e.g. through linux/in.h), then __BYTE_ORDER equals __LITTLE_ENDIAN since both are undefined, after the include which correctly pulls in linux/byteorder/little_endian.h, __LITTLE_ENDIAN is defined, but given __BYTE_ORDER is still undefined, we match on __BYTE_ORDER equals to __BIG_ENDIAN since __BIG_ENDIAN is also undefined at that point, sigh. ii) But even that would be wrong, since when compiling the test cases with clang, one can select between bpfeb and bpfel targets for cross compilation. Hence, we can also not rely on what the system's endian.h provides, but we need to look at the compiler's defined endianness. The compiler defines __BYTE_ORDER__, and we can match __ORDER_LITTLE_ENDIAN__ and __ORDER_BIG_ENDIAN__, which also reflects targets bpf (native), bpfel, bpfeb correctly, thus really only rely on that. After patch: # ./test_progs test_pkt_access:PASS:ipv4 74 nsec test_pkt_access:PASS:ipv6 42 nsec test_xdp:PASS:ipv4 2340 nsec test_xdp:PASS:ipv6 1461 nsec test_l4lb:PASS:ipv4 400 nsec test_l4lb:PASS:ipv6 530 nsec test_tcp_estats:PASS: 0 nsec Summary: 7 PASSED, 0 FAILED Fixes: 43bcf707ccdc ("bpf: fix _htons occurences in test_progs") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-08ethtool.h: remind to update 802.3ad when adding new speedsNicolas Dichtel
Each time a new speed is added, the bonding 802.3ad isn't updated. Add a comment to remind the developer to update this driver. Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Acked-by: Andy Gospodarek <andy@greyhouse.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-08bonding: fix 802.3ad support for 14G speedNicolas Dichtel
This patch adds 14 Gbps enum definition, and fixes aggregated bandwidth calculation based on above slave links. Fixes: 0d7e2d2166f6 ("IB/ipoib: add get_link_ksettings in ethtool") Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Acked-by: Andy Gospodarek <andy@greyhouse.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-08bonding: fix 802.3ad support for 5G and 50G speedsThibaut Collet
This patch adds [5|50] Gbps enum definition, and fixes aggregated bandwidth calculation based on above slave links. Fixes: c9a70d43461d ("net-next: ethtool: Added port speed macros.") Signed-off-by: Thibaut Collet <thibaut.collet@6wind.com> Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Acked-by: Andy Gospodarek <andy@greyhouse.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-08openvswitch: warn about missing first netlink attributeNicolas Dichtel
The first netlink attribute (value 0) must always be defined as none/unspec. Because we cannot change an existing UAPI, I add a comment to point the mistake and avoid to propagate it in a new ovs API in the future. Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-08[media] media/cec.h: use IS_REACHABLE instead of IS_ENABLEDHans Verkuil
Fix messages like this: adv7842.c:(.text+0x2edadd): undefined reference to `cec_unregister_adapter' when CEC_CORE=m but the driver including media/cec.h is built-in. In that case the static inlines provided in media/cec.h should be used by that driver. Reported-by: Randy Dunlap <rdunlap@infradead.org> Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-06-08ila_xlat: add missing hash secret initializationArnd Bergmann
While discussing the possible merits of clang warning about unused initialized functions, I found one function that was clearly meant to be called but never actually is. __ila_hash_secret_init() initializes the hash value for the ila locator, apparently this is intended to prevent hash collision attacks, but this ends up being a read-only zero constant since there is no caller. I could find no indication of why it was never called, the earliest patch submission for the module already was like this. If my interpretation is right, we certainly want to backport the patch to stable kernels as well. I considered adding it to the ila_xlat_init callback, but for best effect the random data is read as late as possible, just before it is first used. The underlying net_get_random_once() is already highly optimized to avoid overhead when called frequently. Fixes: 7f00feaf1076 ("ila: Add generic ILA translation facility") Cc: stable@vger.kernel.org Link: https://www.spinics.net/lists/kernel/msg2527243.html Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-08perf symbols: Kill dso__build_id_is_kmod()Namhyung Kim
The commit e7ee40475760 ("perf symbols: Fix symbols searching for module in buildid-cache") added the function to check kernel modules reside in the build-id cache. This was because there's no way to identify a DSO which is actually a kernel module. So it searched linkname of the file and find ".ko" suffix. But this does not work for compressed kernel modules and now such DSOs hCcave correct symtab_type now. So no need to check it anymore. This patch essentially reverts the commit. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Jiri Olsa <jolsa@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Wang Nan <wangnan0@huawei.com> Cc: kernel-team@lge.com Link: http://lkml.kernel.org/r/20170608073109.30699-10-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-06-08perf symbols: Keep DSO->symtab_type after decompressNamhyung Kim
The symsrc__init() overwrites dso->symtab_type as symsrc->type in dso__load_sym(). But for compressed kernel modules in the build-id cache, it should have original symtab type to be decompressed as needed. This fixes perf annotate to show disassembly of the function properly. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Jiri Olsa <jolsa@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Wang Nan <wangnan0@huawei.com> Cc: kernel-team@lge.com Link: http://lkml.kernel.org/r/20170608073109.30699-9-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-06-08perf tests: Decompress kernel module before objdumpNamhyung Kim
If a kernel modules is compressed, it should be decompressed before running objdump to parse binary data correctly. This fixes a failure of object code reading test for me. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Adrian Hunter <adrian.hunter@intel.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Cc: David Ahern <dsahern@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Wang Nan <wangnan0@huawei.com> Cc: kernel-team@lge.com Link: http://lkml.kernel.org/r/20170608073109.30699-8-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-06-08perf tools: Consolidate error path in __open_dso()Namhyung Kim
On failure, it should free the 'name', so clean up the error path using goto. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Suggested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Wang Nan <wangnan0@huawei.com> Cc: kernel-team@lge.com Link: http://lkml.kernel.org/r/20170608073109.30699-7-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-06-08perf tools: Decompress kernel module when reading DSO dataNamhyung Kim
Currently perf decompresses kernel modules when loading the symbol table but it missed to do it when reading raw data. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Jiri Olsa <jolsa@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Wang Nan <wangnan0@huawei.com> Cc: kernel-team@lge.com Link: http://lkml.kernel.org/r/20170608073109.30699-6-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-06-08perf annotate: Use dso__decompress_kmodule_path()Namhyung Kim
Convert open-coded decompress routine to use the function. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Jiri Olsa <jolsa@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Wang Nan <wangnan0@huawei.com> Cc: kernel-team@lge.com Link: http://lkml.kernel.org/r/20170608073109.30699-5-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-06-08perf tools: Introduce dso__decompress_kmodule_{fd,path}Namhyung Kim
Move decompress_kmodule() to util/dso.c and split it into two functions returning fd and (decompressed) file path. The existing user only wants the fd version but the path version will be used soon. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Jiri Olsa <jolsa@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Wang Nan <wangnan0@huawei.com> Cc: kernel-team@lge.com Link: http://lkml.kernel.org/r/20170608073109.30699-4-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-06-08perf tools: Fix a memory leak in __open_dso()Namhyung Kim
The 'name' variable should be freed on the error path. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Jiri Olsa <jolsa@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Wang Nan <wangnan0@huawei.com> Cc: kernel-team@lge.com Link: http://lkml.kernel.org/r/20170608073109.30699-3-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-06-08perf annotate: Fix symbolic link of build-id cacheNamhyung Kim
The commit 6ebd2547dd24 ("perf annotate: Fix a bug following symbolic link of a build-id file") changed to use dirname to follow the symlink. But it only considers new-style build-id cache names so old names fail on readlink() and force to use system path which might not available. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Jiri Olsa <jolsa@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Taeung Song <treeze.taeung@gmail.com> Cc: Wang Nan <wangnan0@huawei.com> Cc: kernel-team@lge.com Fixes: 6ebd2547dd24 ("perf annotate: Fix a bug following symbolic link of a build-id file") Link: http://lkml.kernel.org/r/20170608073109.30699-2-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-06-08Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk Pull printk fix from Petr Mladek: "This reverts a fix added into 4.12-rc1. It caused the kernel log to be printed on another console when two consoles of the same type were defined, e.g. console=ttyS0 console=ttyS1. This configuration was never supported by kernel itself, but it started to make sense with systemd. In other words, the commit broke userspace" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk: Revert "printk: fix double printing with earlycon"
2017-06-08Merge branch 'linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 Pull crypto fixes from Herbert Xu: "This fixes a couple of places in the crypto code that were doing interruptible sleeps dangerously. They have been converted to use non-interruptible sleeps. This also fixes a bug in asymmetric_keys where it would trigger a use-after-free if a request returned EBUSY due to a full device queue" * 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: crypto: gcm - wait for crypto op not signal safe crypto: drbg - wait for crypto op not signal safe crypto: asymmetric_keys - handle EBUSY due to backlog correctly
2017-06-08net: Fix build regression in rtl8723bs staging driver.David S. Miller
drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c: In function ‘rtw_cfg80211_add_monitor_if’: drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c:2670:10: error: ‘struct net_device’ has no member named ‘destructor’ mon_ndev->destructor = rtw_ndev_destructor; ^ Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-08block, bfq: access and cache blkg data only when safePaolo Valente
In blk-cgroup, operations on blkg objects are protected with the request_queue lock. This is no more the lock that protects I/O-scheduler operations in blk-mq. In fact, the latter are now protected with a finer-grained per-scheduler-instance lock. As a consequence, although blkg lookups are also rcu-protected, blk-mq I/O schedulers may see inconsistent data when they access blkg and blkg-related objects. BFQ does access these objects, and does incur this problem, in the following case. The blkg_lookup performed in bfq_get_queue, being protected (only) through rcu, may happen to return the address of a copy of the original blkg. If this is the case, then the blkg_get performed in bfq_get_queue, to pin down the blkg, is useless: it does not prevent blk-cgroup code from destroying both the original blkg and all objects directly or indirectly referred by the copy of the blkg. BFQ accesses these objects, which typically causes a crash for NULL-pointer dereference of memory-protection violation. Some additional protection mechanism should be added to blk-cgroup to address this issue. In the meantime, this commit provides a quick temporary fix for BFQ: cache (when safe) blkg data that might disappear right after a blkg_lookup. In particular, this commit exploits the following facts to achieve its goal without introducing further locks. Destroy operations on a blkg invoke, as a first step, hooks of the scheduler associated with the blkg. And these hooks are executed with bfqd->lock held for BFQ. As a consequence, for any blkg associated with the request queue an instance of BFQ is attached to, we are guaranteed that such a blkg is not destroyed, and that all the pointers it contains are consistent, while that instance is holding its bfqd->lock. A blkg_lookup performed with bfqd->lock held then returns a fully consistent blkg, which remains consistent until this lock is held. In more detail, this holds even if the returned blkg is a copy of the original one. Finally, also the object describing a group inside BFQ needs to be protected from destruction on the blkg_free of the original blkg (which invokes bfq_pd_free). This commit adds private refcounting for this object, to let it disappear only after no bfq_queue refers to it any longer. This commit also removes or updates some stale comments on locking issues related to blk-cgroup operations. Reported-by: Tomas Konir <tomas.konir@gmail.com> Reported-by: Lee Tibbert <lee.tibbert@gmail.com> Reported-by: Marco Piazza <mpiazza@gmail.com> Signed-off-by: Paolo Valente <paolo.valente@linaro.org> Tested-by: Tomas Konir <tomas.konir@gmail.com> Tested-by: Lee Tibbert <lee.tibbert@gmail.com> Tested-by: Marco Piazza <mpiazza@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-06-08Merge branch 'netvsc-bug-fixes'David S. Miller
Stephen Hemminger says: ==================== netvsc: bug fixes These are bugfixes for netvsc driver in 4.12. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-08netvsc: move filter setting to rndis_devicestephen hemminger
The work queue and handling of network filter parameters should be in rndis_device. This gets rid of warning from RCU checks, eliminates a race and cleans up code. Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-08netvsc: fix net poll modestephen hemminger
The ndo_poll_controller function needs to schedule NAPI to pick up arriving packets and send completions. Otherwise no data will ever be received. For simple case of netconsole, it also will allow send completions to happen. Without this netpoll will eventually get stuck. Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-08netvsc: fix rcu dereference warning from ethtoolstephen hemminger
The ethtool info command calls the netvsc get_sset_count with RTNL but not with RCU. Which causes warning: drivers/net/hyperv/netvsc_drv.c:1010 suspicious rcu_dereference_check() usage! Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-08rcu: Use RCU_NOCB_WAKE rather than RCU_NOGP_WAKEPaul E. McKenney
The RCU_NOGP_WAKE_NOT, RCU_NOGP_WAKE, and RCU_NOGP_WAKE_FORCE flags are used to mediate wakeups for the no-CBs CPU kthreads. The "NOGP" really doesn't make any sense, so this commit does s/NOGP/NOCB/. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08sched: Rely on synchronize_rcu_mult() de-duplicationPaul E. McKenney
The synchronize_rcu_mult() function now detects duplicate requests for the same grace-period flavor and waits only once for each flavor. This commit therefore removes the ugly #ifdef from sched_cpu_deactivate() because synchronize_rcu_mult(call_rcu, call_rcu_sched) now does what the #ifdef used to be needed for. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de>
2017-06-08rcu: Make synchronize_rcu_mult() check for duplicatesPaul E. McKenney
Currently, doing synchronize_rcu_mult(call_rcu, call_rcu) might (or might not) wait for two RCU grace periods. One approach is of course "don't do that!", but in CONFIG_PREEMPT=n kernels, synchronize_rcu_mult(call_rcu, call_rcu_sched) does exactly that. This results in an ugly #ifdef in sched_cpu_deactivate(). This commit therefore makes __wait_rcu_gp() check for duplicates, which in turn allows duplicates to be passed to synchronize_rcu_mult() without risk of waiting twice on the same type of grace period. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08srcu: Add DEBUG_OBJECTS_RCU_HEAD functionalityPaul E. McKenney
This commit adds DEBUG_OBJECTS_RCU_HEAD checking to detect call_srcu() counterparts to double-free bugs. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08srcu: Shrink Tiny SRCU a bitPaul E. McKenney
In Tiny SRCU, __srcu_read_lock() is a trivial function, outweighed by its EXPORT_SYMBOL_GPL(), and on many architectures, its call sequence. This commit therefore moves it to srcutiny.h so that it can be inlined. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08srcu: Make SRCU be once again optionalPaul E. McKenney
Commit d160a727c40e ("srcu: Make SRCU be built by default") in response to build errors, which were caused by code that included srcu.h despite !SRCU. However, srcutiny.o is almost 2K of code, which is not insignificant for those attempting to run the Linux kernel on IoT devices. This commit therefore makes SRCU be once again optional, and adjusts srcu.h to allow error-free inclusion in !SRCU kernel builds. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Nicolas Pitre <nico@linaro.org>
2017-06-08rcu: Add lockdep_assert_held() teeth to tree_plugin.hPaul E. McKenney
Comments can be helpful, but assertions carry more force. This commit therefore adds lockdep_assert_held() and RCU_LOCKDEP_WARN() calls to enforce lock-held and interrupt-disabled preconditions. Reported-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08rcu: Add lockdep_assert_held() teeth to tree.cPaul E. McKenney
Comments can be helpful, but assertions carry more force. This commit therefore adds lockdep_assert_held() and RCU_LOCKDEP_WARN() calls to enforce lock-held and interrupt-disabled preconditions. Reported-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08srcu: Print non-default exp_holdoff values at boot timePaul E. McKenney
This commit makes srcu_bootup_announce() check for non-default values of the auto-expedite holdoff time exp_holdoff and print a message if so. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08srcu: Make exp_holdoff module parameter be staticPaul E. McKenney
Because exp_holdoff is not used outside of srcutree.c, it can be static. This commit therefore makes this change. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08rcu: Update rcu_bootup_announce_oddness()Paul E. McKenney
This commit updates rcu_bootup_announce_oddness() to check additional Kconfig options and module/boot parameters. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08rcu: Print out rcupdate.c non-default boot-time settingsPaul E. McKenney
This commit adds a rcupdate_announce_bootup_oddness() function to print out non-default values of significant kernel boot parameter settings to aid in debugging. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08rcu: Add preemptibility checks in rcu_sched_qs() and rcu_bh_qs()Paul E. McKenney
This commit adds WARN_ON_ONCE() calls that trigger if either rcu_sched_qs() or rcu_bh_qs() are invoked with preemption enabled. In the immortal words of Peter Zijlstra: "these are much harder to ignore than comments". Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08doc: Take tail recursion into account in RCU requirementsPaul E. McKenney
This commit classifies tail recursion as an alternative way to write a loop, with similar limitations. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08srcu: Document auto-expediting requirementPaul E. McKenney
This commit documents the auto-expediting requirement satisfied by commits 2da4b2a7fd8d ("srcu: Expedite first synchronize_srcu() when idle") and 22607d66bbc3 ("srcu: Specify auto-expedite holdoff time"). Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08rcutorture: Add "git diff" output to testid.txt filePaul E. McKenney
Currently, when running from a git archive, the testid.txt file contains only the branch name, the output of "git status", and the SHA-1 of the current HEAD. This is useful, but does not uniquely identify the source code that was built. This commit therefore adds the output of "git diff HEAD", which means that if two testid.txt files compare equal, they correspond to exactly the same source code. Give or take the possibility of SHA-1 collisions, that is. ;-) Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08rcuperf: Add writer_holdoff boot parameterPaul E. McKenney
This commit adds a writer_holdoff boot parameter to rcuperf, which is intended to be used to test Tree SRCU's auto-expediting. This boot parameter is in microseconds, and defaults to zero (that is, disabled). Set it to a bit larger than srcutree.exp_holdoff, keeping the nanosecond/microsecond conversion, to force Tree SRCU to auto-expedite more aggressively. This commit also adds documentation for this parameter, and fixes some alphabetization while in the neighborhood. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08srcu-cbmc: Use /usr/bin/awk instead of /bin/awkPriyalee Kushwaha
Most OS distribution have awk in /usr/bin not in /bin Without this patch, kernel-devsrc fails to build as runtime dependency for srcu-cbmc script /bin/awk is not found. Signed-off-by: Kushwaha, Priyalee <priyalee.kushwaha@intel.com> Acked-by: Lance Roy <ldr709@gmail.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08rcuperf: Set more user-friendly defaultsPaul E. McKenney
Common-case use of rcuperf must set rcuperf.nreaders=0 and if not built as a module, rcuperf.shutdown. This commit therefore sets the default for rcuperf.nreaders to zero and sets the default for rcuperf.shutdown to zero if rcuperf is built as a module and to one otherwise. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2017-06-08srcu: Shrink Tiny SRCU a bit morePaul E. McKenney
This commit rearranges Tiny SRCU's srcu_struct structure, substitutes u8 for bool, and shrinks counters down to short. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>