diff options
author | Ingo Molnar <mingo@kernel.org> | 2015-01-21 06:12:21 +0100 |
---|---|---|
committer | Ingo Molnar <mingo@kernel.org> | 2015-01-21 06:12:21 +0100 |
commit | f49028292c13b958fdf4f36c8cc8119d0dde187b (patch) | |
tree | ea1f92969a8aca7083f19c4ef07dd3674509554f | |
parent | eef8f4c2acac6fae84f2d959a145fa3cad4d00c9 (diff) | |
parent | 78e691f4ae2d5edea0199ca802bb505b9cdced88 (diff) |
Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu
Pull RCU updates from Paul E. McKenney:
- Documentation updates.
- Miscellaneous fixes.
- Preemptible-RCU fixes, including fixing an old bug in the
interaction of RCU priority boosting and CPU hotplug.
- SRCU updates.
- RCU CPU stall-warning updates.
- RCU torture-test updates.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
48 files changed, 657 insertions, 586 deletions
diff --git a/Documentation/RCU/stallwarn.txt b/Documentation/RCU/stallwarn.txt index ed186a902d31..b57c0c1cdac6 100644 --- a/Documentation/RCU/stallwarn.txt +++ b/Documentation/RCU/stallwarn.txt @@ -15,7 +15,7 @@ CONFIG_RCU_CPU_STALL_TIMEOUT 21 seconds. This configuration parameter may be changed at runtime via the - /sys/module/rcutree/parameters/rcu_cpu_stall_timeout, however + /sys/module/rcupdate/parameters/rcu_cpu_stall_timeout, however this parameter is checked only at the beginning of a cycle. So if you are 10 seconds into a 40-second stall, setting this sysfs parameter to (say) five will shorten the timeout for the @@ -152,6 +152,15 @@ no non-lazy callbacks ("." is printed otherwise, as shown above) and "D" indicates that dyntick-idle processing is enabled ("." is printed otherwise, for example, if disabled via the "nohz=" kernel boot parameter). +If the relevant grace-period kthread has been unable to run prior to +the stall warning, the following additional line is printed: + + rcu_preempt kthread starved for 2023 jiffies! + +Starving the grace-period kthreads of CPU time can of course result in +RCU CPU stall warnings even when all CPUs and tasks have passed through +the required quiescent states. + Multiple Warnings From One Stall @@ -187,6 +196,11 @@ o For !CONFIG_PREEMPT kernels, a CPU looping anywhere in the behavior, you might need to replace some of the cond_resched() calls with calls to cond_resched_rcu_qs(). +o Anything that prevents RCU's grace-period kthreads from running. + This can result in the "All QSes seen" console-log message. + This message will include information on when the kthread last + ran and how often it should be expected to run. + o A CPU-bound real-time task in a CONFIG_PREEMPT kernel, which might happen to preempt a low-priority task in the middle of an RCU read-side critical section. This is especially damaging if diff --git a/Documentation/RCU/trace.txt b/Documentation/RCU/trace.txt index b63b9bb3bc0c..08651da15448 100644 --- a/Documentation/RCU/trace.txt +++ b/Documentation/RCU/trace.txt @@ -56,14 +56,14 @@ rcuboost: The output of "cat rcu/rcu_preempt/rcudata" looks as follows: - 0!c=30455 g=30456 pq=1 qp=1 dt=126535/140000000000000/0 df=2002 of=4 ql=0/0 qs=N... b=10 ci=74572 nci=0 co=1131 ca=716 - 1!c=30719 g=30720 pq=1 qp=0 dt=132007/140000000000000/0 df=1874 of=10 ql=0/0 qs=N... b=10 ci=123209 nci=0 co=685 ca=982 - 2!c=30150 g=30151 pq=1 qp=1 dt=138537/140000000000000/0 df=1707 of=8 ql=0/0 qs=N... b=10 ci=80132 nci=0 co=1328 ca=1458 - 3 c=31249 g=31250 pq=1 qp=0 dt=107255/140000000000000/0 df=1749 of=6 ql=0/450 qs=NRW. b=10 ci=151700 nci=0 co=509 ca=622 - 4!c=29502 g=29503 pq=1 qp=1 dt=83647/140000000000000/0 df=965 of=5 ql=0/0 qs=N... b=10 ci=65643 nci=0 co=1373 ca=1521 - 5 c=31201 g=31202 pq=1 qp=1 dt=70422/0/0 df=535 of=7 ql=0/0 qs=.... b=10 ci=58500 nci=0 co=764 ca=698 - 6!c=30253 g=30254 pq=1 qp=1 dt=95363/140000000000000/0 df=780 of=5 ql=0/0 qs=N... b=10 ci=100607 nci=0 co=1414 ca=1353 - 7 c=31178 g=31178 pq=1 qp=0 dt=91536/0/0 df=547 of=4 ql=0/0 qs=.... b=10 ci=109819 nci=0 co=1115 ca=969 + 0!c=30455 g=30456 pq=1/0 qp=1 dt=126535/140000000000000/0 df=2002 of=4 ql=0/0 qs=N... b=10 ci=74572 nci=0 co=1131 ca=716 + 1!c=30719 g=30720 pq=1/0 qp=0 dt=132007/140000000000000/0 df=1874 of=10 ql=0/0 qs=N... b=10 ci=123209 nci=0 co=685 ca=982 + 2!c=30150 g=30151 pq=1/1 qp=1 dt=138537/140000000000000/0 df=1707 of=8 ql=0/0 qs=N... b=10 ci=80132 nci=0 co=1328 ca=1458 + 3 c=31249 g=31250 pq=1/1 qp=0 dt=107255/140000000000000/0 df=1749 of=6 ql=0/450 qs=NRW. b=10 ci=151700 nci=0 co=509 ca=622 + 4!c=29502 g=29503 pq=1/0 qp=1 dt=83647/140000000000000/0 df=965 of=5 ql=0/0 qs=N... b=10 ci=65643 nci=0 co=1373 ca=1521 + 5 c=31201 g=31202 pq=1/0 qp=1 dt=70422/0/0 df=535 of=7 ql=0/0 qs=.... b=10 ci=58500 nci=0 co=764 ca=698 + 6!c=30253 g=30254 pq=1/0 qp=1 dt=95363/140000000000000/0 df=780 of=5 ql=0/0 qs=N... b=10 ci=100607 nci=0 co=1414 ca=1353 + 7 c=31178 g=31178 pq=1/0 qp=0 dt=91536/0/0 df=547 of=4 ql=0/0 qs=.... b=10 ci=109819 nci=0 co=1115 ca=969 This file has one line per CPU, or eight for this 8-CPU system. The fields are as follows: @@ -188,14 +188,14 @@ o "ca" is the number of RCU callbacks that have been adopted by this Kernels compiled with CONFIG_RCU_BOOST=y display the following from /debug/rcu/rcu_preempt/rcudata: - 0!c=12865 g=12866 pq=1 qp=1 dt=83113/140000000000000/0 df=288 of=11 ql=0/0 qs=N... kt=0/O ktl=944 b=10 ci=60709 nci=0 co=748 ca=871 - 1 c=14407 g=14408 pq=1 qp=0 dt=100679/140000000000000/0 df=378 of=7 ql=0/119 qs=NRW. kt=0/W ktl=9b6 b=10 ci=109740 nci=0 co=589 ca=485 - 2 c=14407 g=14408 pq=1 qp=0 dt=105486/0/0 df=90 of=9 ql=0/89 qs=NRW. kt=0/W ktl=c0c b=10 ci=83113 nci=0 co=533 ca=490 - 3 c=14407 g=14408 pq=1 qp=0 dt=107138/0/0 df=142 of=8 ql=0/188 qs=NRW. kt=0/W ktl=b96 b=10 ci=121114 nci=0 co=426 ca=290 - 4 c=14405 g=14406 pq=1 qp=1 dt=50238/0/0 df=706 of=7 ql=0/0 qs=.... kt=0/W ktl=812 b=10 ci=34929 nci=0 co=643 ca=114 - 5!c=14168 g=14169 pq=1 qp=0 dt=45465/140000000000000/0 df=161 of=11 ql=0/0 qs=N... kt=0/O ktl=b4d b=10 ci=47712 nci=0 co=677 ca=722 - 6 c=14404 g=14405 pq=1 qp=0 dt=59454/0/0 df=94 of=6 ql=0/0 qs=.... kt=0/W ktl=e57 b=10 ci=55597 nci=0 co=701 ca=811 - 7 c=14407 g=14408 pq=1 qp=1 dt=68850/0/0 df=31 of=8 ql=0/0 qs=.... kt=0/W ktl=14bd b=10 ci=77475 nci=0 co=508 ca=1042 + 0!c=12865 g=12866 pq=1/0 qp=1 dt=83113/140000000000000/0 df=288 of=11 ql=0/0 qs=N... kt=0/O ktl=944 b=10 ci=60709 nci=0 co=748 ca=871 + 1 c=14407 g=14408 pq=1/0 qp=0 dt=100679/140000000000000/0 df=378 of=7 ql=0/119 qs=NRW. kt=0/W ktl=9b6 b=10 ci=109740 nci=0 co=589 ca=485 + 2 c=14407 g=14408 pq=1/0 qp=0 dt=105486/0/0 df=90 of=9 ql=0/89 qs=NRW. kt=0/W ktl=c0c b=10 ci=83113 nci=0 co=533 ca=490 + 3 c=14407 g=14408 pq=1/0 qp=0 dt=107138/0/0 df=142 of=8 ql=0/188 qs=NRW. kt=0/W ktl=b96 b=10 ci=121114 nci=0 co=426 ca=290 + 4 c=14405 g=14406 pq=1/0 qp=1 dt=50238/0/0 df=706 of=7 ql=0/0 qs=.... kt=0/W ktl=812 b=10 ci=34929 nci=0 co=643 ca=114 + 5!c=14168 g=14169 pq=1/0 qp=0 dt=45465/140000000000000/0 df=161 of=11 ql=0/0 qs=N... kt=0/O ktl=b4d b=10 ci=47712 nci=0 co=677 ca=722 + 6 c=14404 g=14405 pq=1/0 qp=0 dt=59454/0/0 df=94 of=6 ql=0/0 qs=.... kt=0/W ktl=e57 b=10 ci=55597 nci=0 co=701 ca=811 + 7 c=14407 g=14408 pq=1/0 qp=1 dt=68850/0/0 df=31 of=8 ql=0/0 qs=.... kt=0/W ktl=14bd b=10 ci=77475 nci=0 co=508 ca=1042 This is similar to the output discussed above, but contains the following additional fields: diff --git a/Documentation/memory-barriers.txt b/Documentation/memory-barriers.txt index 70a09f8a0383..ca2387ef27ab 100644 --- a/Documentation/memory-barriers.txt +++ b/Documentation/memory-barriers.txt @@ -269,6 +269,50 @@ And there are a number of things that _must_ or _must_not_ be assumed: STORE *(A + 4) = Y; STORE *A = X; STORE {*A, *(A + 4) } = {X, Y}; +And there are anti-guarantees: + + (*) These guarantees do not apply to bitfields, because compilers often + generate code to modify these using non-atomic read-modify-write + sequences. Do not attempt to use bitfields to synchronize parallel + algorithms. + + (*) Even in cases where bitfields are protected by locks, all fields + in a given bitfield must be protected by one lock. If two fields + in a given bitfield are protected by different locks, the compiler's + non-atomic read-modify-write sequences can cause an update to one + field to corrupt the value of an adjacent field. + + (*) These guarantees apply only to properly aligned and sized scalar + variables. "Properly sized" currently means variables that are + the same size as "char", "short", "int" and "long". "Properly + aligned" means the natural alignment, thus no constraints for + "char", two-byte alignment for "short", four-byte alignment for + "int", and either four-byte or eight-byte alignment for "long", + on 32-bit and 64-bit systems, respectively. Note that these + guarantees were introduced into the C11 standard, so beware when + using older pre-C11 compilers (for example, gcc 4.6). The portion + of the standard containing this guarantee is Section 3.14, which + defines "memory location" as follows: + + memory location + either an object of scalar type, or a maximal sequence + of adjacent bit-fields all having nonzero width + + NOTE 1: Two threads of execution can update and access + separate memory locations without interfering with + each other. + + NOTE 2: A bit-field and an adjacent non-bit-field member + are in separate memory locations. The same applies + to two bit-fields, if one is declared inside a nested + structure declaration and the other is not, or if the two + are separated by a zero-length bit-field declaration, + or if they are separated by a non-bit-field member + declaration. It is not safe to concurrently update two + bit-fields in the same structure if all members declared + between them are also bit-fields, no matter what the + sizes of those intervening bit-fields happen to be. + ========================= WHAT ARE MEMORY BARRIERS? @@ -750,7 +794,7 @@ In summary: However, they do -not- guarantee any other sort of ordering: Not prior loads against later loads, nor prior stores against later anything. If you need these other forms of ordering, - use smb_rmb(), smp_wmb(), or, in the case of prior stores and + use smp_rmb(), smp_wmb(), or, in the case of prior stores and later loads, smp_mb(). (*) If both legs of the "if" statement begin with identical stores diff --git a/arch/arm/kvm/Kconfig b/arch/arm/kvm/Kconfig index 466bd299b1a8..3afee5f40f4f 100644 --- a/arch/arm/kvm/Kconfig +++ b/arch/arm/kvm/Kconfig @@ -23,6 +23,7 @@ config KVM select HAVE_KVM_CPU_RELAX_INTERCEPT select KVM_MMIO select KVM_ARM_HOST + select SRCU depends on ARM_VIRT_EXT && ARM_LPAE ---help--- Support hosting virtualized guest machines. You will also diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig index 8ba85e9ea388..b334084d3675 100644 --- a/arch/arm64/kvm/Kconfig +++ b/arch/arm64/kvm/Kconfig @@ -26,6 +26,7 @@ config KVM select KVM_ARM_HOST select KVM_ARM_VGIC select KVM_ARM_TIMER + select SRCU ---help--- Support hosting virtualized guest machines. diff --git a/arch/mips/kvm/Kconfig b/arch/mips/kvm/Kconfig index 30e334e823bd..2ae12825529f 100644 --- a/arch/mips/kvm/Kconfig +++ b/arch/mips/kvm/Kconfig @@ -20,6 +20,7 @@ config KVM select PREEMPT_NOTIFIERS select ANON_INODES select KVM_MMIO + select SRCU ---help--- Support for hosting Guest kernels. Currently supported on MIPS32 processors. diff --git a/arch/powerpc/kvm/Kconfig b/arch/powerpc/kvm/Kconfig index f5769f19ae25..11850f310fb4 100644 --- a/arch/powerpc/kvm/Kconfig +++ b/arch/powerpc/kvm/Kconfig @@ -21,6 +21,7 @@ config KVM select PREEMPT_NOTIFIERS select ANON_INODES select HAVE_KVM_EVENTFD + select SRCU config KVM_BOOK3S_HANDLER bool diff --git a/arch/s390/kvm/Kconfig b/arch/s390/kvm/Kconfig index 646db9c467d1..5fce52cf0e57 100644 --- a/arch/s390/kvm/Kconfig +++ b/arch/s390/kvm/Kconfig @@ -28,6 +28,7 @@ config KVM select HAVE_KVM_IRQCHIP select HAVE_KVM_IRQFD select HAVE_KVM_IRQ_ROUTING + select SRCU ---help--- Support hosting paravirtualized guest machines using the SIE virtualization capability on the mainframe. This should work diff --git a/arch/tile/kvm/Kconfig b/arch/tile/kvm/Kconfig index 2298cb1daff7..1e968f7550dc 100644 --- a/arch/tile/kvm/Kconfig +++ b/arch/tile/kvm/Kconfig @@ -21,6 +21,7 @@ config KVM depends on HAVE_KVM && MODULES select PREEMPT_NOTIFIERS select ANON_INODES + select SRCU ---help--- Support hosting paravirtualized guest machines. diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index ba397bde7948..661269953c1a 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -138,6 +138,7 @@ config X86 select HAVE_ACPI_APEI_NMI if ACPI select ACPI_LEGACY_TABLES_LOOKUP if ACPI select X86_FEATURE_NAMES if PROC_FS + select SRCU config INSTRUCTION_DECODER def_bool y diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig index f9d16ff56c6b..7dc7ba577ecd 100644 --- a/arch/x86/kvm/Kconfig +++ b/arch/x86/kvm/Kconfig @@ -40,6 +40,7 @@ config KVM select HAVE_KVM_MSI select HAVE_KVM_CPU_RELAX_INTERCEPT select KVM_VFIO + select SRCU ---help--- Support hosting fully virtualized guest machines using hardware virtualization extensions. You will need a fairly recent diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig index 3f44f292d066..91f86131bb7a 100644 --- a/drivers/clk/Kconfig +++ b/drivers/clk/Kconfig @@ -13,6 +13,7 @@ config COMMON_CLK bool select HAVE_CLK_PREPARE select CLKDEV_LOOKUP + select SRCU ---help--- The common clock framework is a single definition of struct clk, useful across many platforms, as well as an diff --git a/drivers/cpufreq/Kconfig b/drivers/cpufreq/Kconfig index 29b2ef5a68b9..a171fef2c2b6 100644 --- a/drivers/cpufreq/Kconfig +++ b/drivers/cpufreq/Kconfig @@ -2,6 +2,7 @@ menu "CPU Frequency scaling" config CPU_FREQ bool "CPU Frequency scaling" + select SRCU help CPU Frequency scaling allows you to change the clock speed of CPUs on the fly. This is a nice method to save power, because diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig index faf4e70c42e0..3891f6781298 100644 --- a/drivers/devfreq/Kconfig +++ b/drivers/devfreq/Kconfig @@ -1,5 +1,6 @@ menuconfig PM_DEVFREQ bool "Generic Dynamic Voltage and Frequency Scaling (DVFS) support" + select SRCU help A device may have a list of frequencies and voltages available. devfreq, a generic DVFS framework can be registered for a device diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig index 5bdedf6df153..c355a226a024 100644 --- a/drivers/md/Kconfig +++ b/drivers/md/Kconfig @@ -5,6 +5,7 @@ menuconfig MD bool "Multiple devices driver support (RAID and LVM)" depends on BLOCK + select SRCU help Support multiple physical spindles through a single logical device. Required for RAID and logical volume management. diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig index d6607ee9c855..84673ebcf428 100644 --- a/drivers/net/Kconfig +++ b/drivers/net/Kconfig @@ -197,6 +197,7 @@ config NETCONSOLE_DYNAMIC config NETPOLL def_bool NETCONSOLE + select SRCU config NET_POLL_CONTROLLER def_bool NETPOLL diff --git a/fs/btrfs/Kconfig b/fs/btrfs/Kconfig index a66768ebc8d1..80e9c18ea64f 100644 --- a/fs/btrfs/Kconfig +++ b/fs/btrfs/Kconfig @@ -8,6 +8,7 @@ config BTRFS_FS select LZO_DECOMPRESS select RAID6_PQ select XOR_BLOCKS + select SRCU help Btrfs is a general purpose copy-on-write filesystem with extents, diff --git a/fs/notify/Kconfig b/fs/notify/Kconfig index 22c629eedd82..2a24249b30af 100644 --- a/fs/notify/Kconfig +++ b/fs/notify/Kconfig @@ -1,5 +1,6 @@ config FSNOTIFY def_bool n + select SRCU source "fs/notify/dnotify/Kconfig" source "fs/notify/inotify/Kconfig" diff --git a/fs/quota/Kconfig b/fs/quota/Kconfig index c51df1dd237e..4a09975aac90 100644 --- a/fs/quota/Kconfig +++ b/fs/quota/Kconfig @@ -5,6 +5,7 @@ config QUOTA bool "Quota support" select QUOTACTL + select SRCU help If you say Y here, you will be able to set per user limits for disk usage (also called disk quotas). Currently, it works for the diff --git a/include/linux/compiler.h b/include/linux/compiler.h index 33063f872ee3..176bf816875e 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -385,7 +385,7 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s /* Is this type a native word size -- useful for atomic operations */ #ifndef __native_word -# define __native_word(t) (sizeof(t) == sizeof(int) || sizeof(t) == sizeof(long)) +# define __native_word(t) (sizeof(t) == sizeof(char) || sizeof(t) == sizeof(short) || sizeof(t) == sizeof(int) || sizeof(t) == sizeof(long)) #endif /* Compile time object size, -1 for unknown */ diff --git a/include/linux/rculist.h b/include/linux/rculist.h index 529bc946f450..a18b16f1dc0e 100644 --- a/include/linux/rculist.h +++ b/include/linux/rculist.h @@ -524,11 +524,11 @@ static inline void hlist_add_behind_rcu(struct hlist_node *n, * @member: the name of the hlist_node within the struct. */ #define hlist_for_each_entry_continue_rcu(pos, member) \ - for (pos = hlist_entry_safe(rcu_dereference((pos)->member.next),\ - typeof(*(pos)), member); \ + for (pos = hlist_entry_safe(rcu_dereference_raw(hlist_next_rcu( \ + &(pos)->member)), typeof(*(pos)), member); \ pos; \ - pos = hlist_entry_safe(rcu_dereference((pos)->member.next),\ - typeof(*(pos)), member)) + pos = hlist_entry_safe(rcu_dereference_raw(hlist_next_rcu( \ + &(pos)->member)), typeof(*(pos)), member)) /** * hlist_for_each_entry_continue_rcu_bh - iterate over a hlist continuing after current point @@ -536,11 +536,11 @@ static inline void hlist_add_behind_rcu(struct hlist_node *n, * @member: the name of the hlist_node within the struct. */ #define hlist_for_each_entry_continue_rcu_bh(pos, member) \ - for (pos = hlist_entry_safe(rcu_dereference_bh((pos)->member.next),\ - typeof(*(pos)), member); \ + for (pos = hlist_entry_safe(rcu_dereference_bh(hlist_next_rcu( \ + &(pos)->member)), typeof(*(pos)), member); \ pos; \ - pos = hlist_entry_safe(rcu_dereference_bh((pos)->member.next),\ - typeof(*(pos)), member)) + pos = hlist_entry_safe(rcu_dereference_bh(hlist_next_rcu( \ + &(pos)->member)), typeof(*(pos)), member)) /** * hlist_for_each_entry_from_rcu - iterate over a hlist continuing from current point diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index ed4f5939a452..78097491cd99 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -331,12 +331,13 @@ static inline void rcu_init_nohz(void) extern struct srcu_struct tasks_rcu_exit_srcu; #define rcu_note_voluntary_context_switch(t) \ do { \ + rcu_all_qs(); \ if (ACCESS_ONCE((t)->rcu_tasks_holdout)) \ ACCESS_ONCE((t)->rcu_tasks_holdout) = false; \ } while (0) #else /* #ifdef CONFIG_TASKS_RCU */ #define TASKS_RCU(x) do { } while (0) -#define rcu_note_voluntary_context_switch(t) do { } while (0) +#define rcu_note_voluntary_context_switch(t) rcu_all_qs() #endif /* #else #ifdef CONFIG_TASKS_RCU */ /** @@ -582,11 +583,11 @@ static inline void rcu_preempt_sleep_check(void) }) #define __rcu_dereference_check(p, c, space) \ ({ \ - typeof(*p) *_________p1 = (typeof(*p) *__force)ACCESS_ONCE(p); \ + /* Dependency order vs. p above. */ \ + typeof(*p) *________p1 = (typeof(*p) *__force)lockless_dereference(p); \ rcu_lockdep_assert(c, "suspicious rcu_dereference_check() usage"); \ rcu_dereference_sparse(p, space); \ - smp_read_barrier_depends(); /* Dependency order vs. p above. */ \ - ((typeof(*p) __force __kernel *)(_________p1)); \ + ((typeof(*p) __force __kernel *)(________p1)); \ }) #define __rcu_dereference_protected(p, c, space) \ ({ \ @@ -603,10 +604,10 @@ static inline void rcu_preempt_sleep_check(void) }) #define __rcu_dereference_index_check(p, c) \ ({ \ - typeof(p) _________p1 = ACCESS_ONCE(p); \ + /* Dependency order vs. p above. */ \ + typeof(p) _________p1 = lockless_dereference(p); \ rcu_lockdep_assert(c, \ "suspicious rcu_dereference_index_check() usage"); \ - smp_read_barrier_depends(); /* Dependency order vs. p above. */ \ (_________p1); \ }) diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h index 0e5366200154..937edaeb150d 100644 --- a/include/linux/rcutiny.h +++ b/include/linux/rcutiny.h @@ -92,17 +92,49 @@ static inline void rcu_virt_note_context_switch(int cpu) } /* - * Return the number of grace periods. + * Return the number of grace periods started. */ -static inline long rcu_batches_completed(void) +static inline unsigned long rcu_batches_started(void) { return 0; } /* - * Return the number of bottom-half grace periods. + * Return the number of bottom-half grace periods started. */ -static inline long rcu_batches_completed_bh(void) +static inline unsigned long rcu_batches_started_bh(void) +{ + return 0; +} + +/* + * Return the number of sched grace periods started. + */ +static inline unsigned long rcu_batches_started_sched(void) +{ + return 0; +} + +/* + * Return the number of grace periods completed. + */ +static inline unsigned long rcu_batches_completed(void) +{ + return 0; +} + +/* + * Return the number of bottom-half grace periods completed. + */ +static inline unsigned long rcu_batches_completed_bh(void) +{ + return 0; +} + +/* + * Return the number of sched grace periods completed. + */ +static inline unsigned long rcu_batches_completed_sched(void) { return 0; } @@ -154,7 +186,10 @@ static inline bool rcu_is_watching(void) return true; } - #endif /* #else defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_RCU_TRACE) */ +static inline void rcu_all_qs(void) +{ +} + #endif /* __LINUX_RCUTINY_H */ diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h index 52953790dcca..d2e583a6aaca 100644 --- a/include/linux/rcutree.h +++ b/include/linux/rcutree.h @@ -81,9 +81,12 @@ void cond_synchronize_rcu(unsigned long oldstate); extern unsigned long rcutorture_testseq; extern unsigned long rcutorture_vernum; -long rcu_batches_completed(void); -long rcu_batches_completed_bh(void); -long rcu_batches_completed_sched(void); +unsigned long rcu_batches_started(void); +unsigned long rcu_batches_started_bh(void); +unsigned long rcu_batches_started_sched(void); +unsigned long rcu_batches_completed(void); +unsigned long rcu_batches_completed_bh(void); +unsigned long rcu_batches_completed_sched(void); void show_rcu_gp_kthreads(void); void rcu_force_quiescent_state(void); @@ -97,4 +100,6 @@ extern int rcu_scheduler_active __read_mostly; bool rcu_is_watching(void); +void rcu_all_qs(void); + #endif /* __LINUX_RCUTREE_H */ diff --git a/include/linux/srcu.h b/include/linux/srcu.h index a2783cb5d275..9cfd9623fb03 100644 --- a/include/linux/srcu.h +++ b/include/linux/srcu.h @@ -45,7 +45,7 @@ struct rcu_batch { #define RCU_BATCH_INIT(name) { NULL, &(name.head) } struct srcu_struct { - unsigned completed; + unsigned long completed; struct srcu_struct_array __percpu *per_cpu_ref; spinlock_t queue_lock; /* protect ->batch_queue, ->running */ bool running; @@ -102,13 +102,11 @@ void process_srcu(struct work_struct *work); * define and init a srcu struct at build time. * dont't call init_srcu_struct() nor cleanup_srcu_struct() on it. */ -#define DEFINE_SRCU(name) \ +#define __DEFINE_SRCU(name, is_static) \ static DEFINE_PER_CPU(struct srcu_struct_array, name##_srcu_array);\ - struct srcu_struct name = __SRCU_STRUCT_INIT(name); - -#define DEFINE_STATIC_SRCU(name) \ - static DEFINE_PER_CPU(struct srcu_struct_array, name##_srcu_array);\ - static struct srcu_struct name = __SRCU_STRUCT_INIT(name); + is_static struct srcu_struct name = __SRCU_STRUCT_INIT(name) +#define DEFINE_SRCU(name) __DEFINE_SRCU(name, /* not static */) +#define DEFINE_STATIC_SRCU(name) __DEFINE_SRCU(name, static) /** * call_srcu() - Queue a callback for invocation after an SRCU grace period @@ -135,7 +133,7 @@ int __srcu_read_lock(struct srcu_struct *sp) __acquires(sp); void __srcu_read_unlock(struct srcu_struct *sp, int idx) __releases(sp); void synchronize_srcu(struct srcu_struct *sp); void synchronize_srcu_expedited(struct srcu_struct *sp); -long srcu_batches_completed(struct srcu_struct *sp); +unsigned long srcu_batches_completed(struct srcu_struct *sp); void srcu_barrier(struct srcu_struct *sp); #ifdef CONFIG_DEBUG_LOCK_ALLOC diff --git a/init/Kconfig b/init/Kconfig index 9afb971497f4 |