From 3a142a0672b48a853f00af61f184c7341ac9c99d Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 25 Feb 2011 22:34:23 +0100 Subject: clockevents: Prevent oneshot mode when broadcast device is periodic When the per cpu timer is marked CLOCK_EVT_FEAT_C3STOP, then we only can switch into oneshot mode, when the backup broadcast device supports oneshot mode as well. Otherwise we would try to switch the broadcast device into an unsupported mode unconditionally. This went unnoticed so far as the current available broadcast devices support oneshot mode. Seth unearthed this problem while debugging and working around an hpet related BIOS wreckage. Add the necessary check to tick_is_oneshot_available(). Reported-and-tested-by: Seth Forshee Signed-off-by: Thomas Gleixner LKML-Reference: Cc: stable@kernel.org # .21 -> --- kernel/time/tick-broadcast.c | 10 ++++++++++ kernel/time/tick-common.c | 6 +++++- kernel/time/tick-internal.h | 3 +++ 3 files changed, 18 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c index 48b2761b5668..a3b5aff62606 100644 --- a/kernel/time/tick-broadcast.c +++ b/kernel/time/tick-broadcast.c @@ -600,4 +600,14 @@ int tick_broadcast_oneshot_active(void) return tick_broadcast_device.mode == TICKDEV_MODE_ONESHOT; } +/* + * Check whether the broadcast device supports oneshot. + */ +bool tick_broadcast_oneshot_available(void) +{ + struct clock_event_device *bc = tick_broadcast_device.evtdev; + + return bc ? bc->features & CLOCK_EVT_FEAT_ONESHOT : false; +} + #endif diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c index 051bc80a0c43..ed228ef6f6b8 100644 --- a/kernel/time/tick-common.c +++ b/kernel/time/tick-common.c @@ -51,7 +51,11 @@ int tick_is_oneshot_available(void) { struct clock_event_device *dev = __this_cpu_read(tick_cpu_device.evtdev); - return dev && (dev->features & CLOCK_EVT_FEAT_ONESHOT); + if (!dev || !(dev->features & CLOCK_EVT_FEAT_ONESHOT)) + return 0; + if (!(dev->features & CLOCK_EVT_FEAT_C3STOP)) + return 1; + return tick_broadcast_oneshot_available(); } /* diff --git a/kernel/time/tick-internal.h b/kernel/time/tick-internal.h index 290eefbc1f60..f65d3a723a64 100644 --- a/kernel/time/tick-internal.h +++ b/kernel/time/tick-internal.h @@ -36,6 +36,7 @@ extern void tick_shutdown_broadcast_oneshot(unsigned int *cpup); extern int tick_resume_broadcast_oneshot(struct clock_event_device *bc); extern int tick_broadcast_oneshot_active(void); extern void tick_check_oneshot_broadcast(int cpu); +bool tick_broadcast_oneshot_available(void); # else /* BROADCAST */ static inline void tick_broadcast_setup_oneshot(struct clock_event_device *bc) { @@ -46,6 +47,7 @@ static inline void tick_broadcast_switch_to_oneshot(void) { } static inline void tick_shutdown_broadcast_oneshot(unsigned int *cpup) { } static inline int tick_broadcast_oneshot_active(void) { return 0; } static inline void tick_check_oneshot_broadcast(int cpu) { } +static inline bool tick_broadcast_oneshot_available(void) { return true; } # endif /* !BROADCAST */ #else /* !ONESHOT */ @@ -76,6 +78,7 @@ static inline int tick_resume_broadcast_oneshot(struct clock_event_device *bc) return 0; } static inline int tick_broadcast_oneshot_active(void) { return 0; } +static inline bool tick_broadcast_oneshot_available(void) { return false; } #endif /* !TICK_ONESHOT */ /* -- cgit v1.2.3 From 2d3a8497f8cc5aca14b722cd37d51f6c15ff9f74 Mon Sep 17 00:00:00 2001 From: Tao Ma Date: Thu, 3 Mar 2011 10:53:20 -0500 Subject: blktrace: Remove blk_fill_rwbs_rq. If we enable trace events to trace block actions, We use blk_fill_rwbs_rq to analyze the corresponding actions in request's cmd_flags, but we only choose the minor 2 bits from it, so most of other flags(e.g, REQ_SYNC) are missing. For example, with a sync write we get: write_test-2409 [001] 160.013869: block_rq_insert: 3,64 W 0 () 258135 + = 8 [write_test] Since now we have integrated the flags of both bio and request, it is safe to pass rq->cmd_flags directly to blk_fill_rwbs and blk_fill_rwbs_rq isn't needed any more. With this patch, after a sync write we get: write_test-2417 [000] 226.603878: block_rq_insert: 3,64 WS 0 () 258135 += 8 [write_test] Signed-off-by: Tao Ma Acked-by: Jeff Moyer Signed-off-by: Jens Axboe --- include/linux/blktrace_api.h | 1 - include/trace/events/block.h | 6 +++--- kernel/trace/blktrace.c | 16 ---------------- 3 files changed, 3 insertions(+), 20 deletions(-) (limited to 'kernel') diff --git a/include/linux/blktrace_api.h b/include/linux/blktrace_api.h index 3395cf7130f5..b22fb0d3db0f 100644 --- a/include/linux/blktrace_api.h +++ b/include/linux/blktrace_api.h @@ -245,7 +245,6 @@ static inline int blk_cmd_buf_len(struct request *rq) extern void blk_dump_cmd(char *buf, struct request *rq); extern void blk_fill_rwbs(char *rwbs, u32 rw, int bytes); -extern void blk_fill_rwbs_rq(char *rwbs, struct request *rq); #endif /* CONFIG_EVENT_TRACING && CONFIG_BLOCK */ diff --git a/include/trace/events/block.h b/include/trace/events/block.h index aba421d68f6f..78f18adb49c8 100644 --- a/include/trace/events/block.h +++ b/include/trace/events/block.h @@ -31,7 +31,7 @@ DECLARE_EVENT_CLASS(block_rq_with_error, 0 : blk_rq_sectors(rq); __entry->errors = rq->errors; - blk_fill_rwbs_rq(__entry->rwbs, rq); + blk_fill_rwbs(__entry->rwbs, rq->cmd_flags, blk_rq_bytes(rq)); blk_dump_cmd(__get_str(cmd), rq); ), @@ -118,7 +118,7 @@ DECLARE_EVENT_CLASS(block_rq, __entry->bytes = (rq->cmd_type == REQ_TYPE_BLOCK_PC) ? blk_rq_bytes(rq) : 0; - blk_fill_rwbs_rq(__entry->rwbs, rq); + blk_fill_rwbs(__entry->rwbs, rq->cmd_flags, blk_rq_bytes(rq)); blk_dump_cmd(__get_str(cmd), rq); memcpy(__entry->comm, current->comm, TASK_COMM_LEN); ), @@ -563,7 +563,7 @@ TRACE_EVENT(block_rq_remap, __entry->nr_sector = blk_rq_sectors(rq); __entry->old_dev = dev; __entry->old_sector = from; - blk_fill_rwbs_rq(__entry->rwbs, rq); + blk_fill_rwbs(__entry->rwbs, rq->cmd_flags, blk_rq_bytes(rq)); ), TP_printk("%d,%d %s %llu + %u <- (%d,%d) %llu", diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index d95721f33702..cbafed7d4f38 100644 --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -1827,21 +1827,5 @@ void blk_fill_rwbs(char *rwbs, u32 rw, int bytes) rwbs[i] = '\0'; } -void blk_fill_rwbs_rq(char *rwbs, struct request *rq) -{ - int rw = rq->cmd_flags & 0x03; - int bytes; - - if (rq->cmd_flags & REQ_DISCARD) - rw |= REQ_DISCARD; - - if (rq->cmd_flags & REQ_SECURE) - rw |= REQ_SECURE; - - bytes = blk_rq_bytes(rq); - - blk_fill_rwbs(rwbs, rw, bytes); -} - #endif /* CONFIG_EVENT_TRACING */ -- cgit v1.2.3 From e3e89cc535223433a619d0969db3fa05cdd946b8 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Fri, 4 Mar 2011 09:23:30 -0800 Subject: Mark ptrace_{traceme,attach,detach} static They are only used inside kernel/ptrace.c, and have been for a long time. We don't want to go back to the bad-old-days when architectures did things on their own, so make them static and private. Signed-off-by: Linus Torvalds --- include/linux/ptrace.h | 3 --- kernel/ptrace.c | 6 +++--- 2 files changed, 3 insertions(+), 6 deletions(-) (limited to 'kernel') diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h index 092a04f874a8..a1147e5dd245 100644 --- a/include/linux/ptrace.h +++ b/include/linux/ptrace.h @@ -102,11 +102,8 @@ extern long arch_ptrace(struct task_struct *child, long request, unsigned long addr, unsigned long data); -extern int ptrace_traceme(void); extern int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len); extern int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len); -extern int ptrace_attach(struct task_struct *tsk); -extern int ptrace_detach(struct task_struct *, unsigned int); extern void ptrace_disable(struct task_struct *); extern int ptrace_check_attach(struct task_struct *task, int kill); extern int ptrace_request(struct task_struct *child, long request, diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 1708b1e2972d..e2302e40b360 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -163,7 +163,7 @@ bool ptrace_may_access(struct task_struct *task, unsigned int mode) return !err; } -int ptrace_attach(struct task_struct *task) +static int ptrace_attach(struct task_struct *task) { int retval; @@ -219,7 +219,7 @@ out: * Performs checks and sets PT_PTRACED. * Should be used by all ptrace implementations for PTRACE_TRACEME. */ -int ptrace_traceme(void) +static int ptrace_traceme(void) { int ret = -EPERM; @@ -293,7 +293,7 @@ static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p) return false; } -int ptrace_detach(struct task_struct *child, unsigned int data) +static int ptrace_detach(struct task_struct *child, unsigned int data) { bool dead = false; -- cgit v1.2.3 From b75f38d659e6fc747eda64cb72f3920e29dd44a4 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Fri, 4 Mar 2011 17:36:21 -0800 Subject: cpuset: add a missing unlock in cpuset_write_resmask() Don't forget to release cgroup_mutex if alloc_trial_cpuset() fails. [akpm@linux-foundation.org: avoid multiple return points] Signed-off-by: Li Zefan Cc: Paul Menage Acked-by: David Rientjes Cc: Miao Xie Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/cpuset.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 4349935c2ad8..e92e98189032 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -1575,8 +1575,10 @@ static int cpuset_write_resmask(struct cgroup *cgrp, struct cftype *cft, return -ENODEV; trialcs = alloc_trial_cpuset(cs); - if (!trialcs) - return -ENOMEM; + if (!trialcs) { + retval = -ENOMEM; + goto out; + } switch (cft->private) { case FILE_CPULIST: @@ -1591,6 +1593,7 @@ static int cpuset_write_resmask(struct cgroup *cgrp, struct cftype *cft, } free_trial_cpuset(trialcs); +out: cgroup_unlock(); return retval; } -- cgit v1.2.3