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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2017-11-17 14:58:01 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-11-17 14:58:01 -0800 |
| commit | 2dcd9c71c1ffa9a036e09047f60e08383bb0abb6 (patch) | |
| tree | 8caabaf493288a3d5adb46ac49ad5097d0c907c7 /kernel/printk | |
| parent | b1c2a344cc19b40d2f1e7cbd9c2f4f205ae6d650 (diff) | |
| parent | a96a5037ed0f52e2d86739f4a1ef985bd036e575 (diff) | |
Merge tag 'trace-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from
- allow module init functions to be traced
- clean up some unused or not used by config events (saves space)
- clean up of trace histogram code
- add support for preempt and interrupt enabled/disable events
- other various clean ups
* tag 'trace-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (30 commits)
tracing, thermal: Hide cpu cooling trace events when not in use
tracing, thermal: Hide devfreq trace events when not in use
ftrace: Kill FTRACE_OPS_FL_PER_CPU
perf/ftrace: Small cleanup
perf/ftrace: Fix function trace events
perf/ftrace: Revert ("perf/ftrace: Fix double traces of perf on ftrace:function")
tracing, dma-buf: Remove unused trace event dma_fence_annotate_wait_on
tracing, memcg, vmscan: Hide trace events when not in use
tracing/xen: Hide events that are not used when X86_PAE is not defined
tracing: mark trace_test_buffer as __maybe_unused
printk: Remove superfluous memory barriers from printk_safe
ftrace: Clear hashes of stale ips of init memory
tracing: Add support for preempt and irq enable/disable events
tracing: Prepare to add preempt and irq trace events
ftrace/kallsyms: Have /proc/kallsyms show saved mod init functions
ftrace: Add freeing algorithm to free ftrace_mod_maps
ftrace: Save module init functions kallsyms symbols for tracing
ftrace: Allow module init functions to be traced
ftrace: Add a ftrace_free_mem() function for modules to use
tracing: Reimplement log2
...
Diffstat (limited to 'kernel/printk')
| -rw-r--r-- | kernel/printk/printk_safe.c | 15 |
1 files changed, 8 insertions, 7 deletions
diff --git a/kernel/printk/printk_safe.c b/kernel/printk/printk_safe.c index 3cdaeaef9ce1..724d9292d4b9 100644 --- a/kernel/printk/printk_safe.c +++ b/kernel/printk/printk_safe.c @@ -39,7 +39,7 @@ * There are situations when we want to make sure that all buffers * were handled or when IRQs are blocked. */ -static int printk_safe_irq_ready; +static int printk_safe_irq_ready __read_mostly; #define SAFE_LOG_BUF_LEN ((1 << CONFIG_PRINTK_SAFE_LOG_BUF_SHIFT) - \ sizeof(atomic_t) - \ @@ -63,11 +63,8 @@ static DEFINE_PER_CPU(struct printk_safe_seq_buf, nmi_print_seq); /* Get flushed in a more safe context. */ static void queue_flush_work(struct printk_safe_seq_buf *s) { - if (printk_safe_irq_ready) { - /* Make sure that IRQ work is really initialized. */ - smp_rmb(); + if (printk_safe_irq_ready) irq_work_queue(&s->work); - } } /* @@ -398,8 +395,12 @@ void __init printk_safe_init(void) #endif } - /* Make sure that IRQ works are initialized before enabling. */ - smp_wmb(); + /* + * In the highly unlikely event that a NMI were to trigger at + * this moment. Make sure IRQ work is set up before this + * variable is set. + */ + barrier(); printk_safe_irq_ready = 1; /* Flush pending messages that did not have scheduled IRQ works. */ |