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| author | Masami Hiramatsu <mhiramat@kernel.org> | 2020-01-11 01:07:16 +0900 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2020-01-13 13:19:42 -0500 |
| commit | 9d15dbbde1048e490f3773e67d7ef7604bab1409 (patch) | |
| tree | d9faf1529c6c73fa4f85a7034c20d8f2225f3365 | |
| parent | 4f712a4d04a4e49167118b41d8ea96df70a98985 (diff) | |
| download | lwn-9d15dbbde1048e490f3773e67d7ef7604bab1409.tar.gz lwn-9d15dbbde1048e490f3773e67d7ef7604bab1409.zip | |
tracing/boot: Add cpu_mask option support
Add ftrace.cpumask option support to boot-time tracing.
This sets cpumask for each instance.
- ftrace.[instance.INSTANCE.]cpumask = CPUMASK;
Set the trace cpumask. Note that the CPUMASK should be a string
which <tracefs>/tracing_cpumask can accepts.
Link: http://lkml.kernel.org/r/157867243625.17873.13613922641273149372.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| -rw-r--r-- | kernel/trace/trace.c | 42 | ||||
| -rw-r--r-- | kernel/trace/trace_boot.c | 14 |
2 files changed, 43 insertions, 13 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 6c996d1b1687..106bbc0988fe 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -4561,20 +4561,13 @@ out_err: return count; } -static ssize_t -tracing_cpumask_write(struct file *filp, const char __user *ubuf, - size_t count, loff_t *ppos) +int tracing_set_cpumask(struct trace_array *tr, + cpumask_var_t tracing_cpumask_new) { - struct trace_array *tr = file_inode(filp)->i_private; - cpumask_var_t tracing_cpumask_new; - int err, cpu; - - if (!alloc_cpumask_var(&tracing_cpumask_new, GFP_KERNEL)) - return -ENOMEM; + int cpu; - err = cpumask_parse_user(ubuf, count, tracing_cpumask_new); - if (err) - goto err_unlock; + if (!tr) + return -EINVAL; local_irq_disable(); arch_spin_lock(&tr->max_lock); @@ -4598,11 +4591,34 @@ tracing_cpumask_write(struct file *filp, const char __user *ubuf, local_irq_enable(); cpumask_copy(tr->tracing_cpumask, tracing_cpumask_new); + + return 0; +} + +static ssize_t +tracing_cpumask_write(struct file *filp, const char __user *ubuf, + size_t count, loff_t *ppos) +{ + struct trace_array *tr = file_inode(filp)->i_private; + cpumask_var_t tracing_cpumask_new; + int err; + + if (!alloc_cpumask_var(&tracing_cpumask_new, GFP_KERNEL)) + return -ENOMEM; + + err = cpumask_parse_user(ubuf, count, tracing_cpumask_new); + if (err) + goto err_free; + + err = tracing_set_cpumask(tr, tracing_cpumask_new); + if (err) + goto err_free; + free_cpumask_var(tracing_cpumask_new); return count; -err_unlock: +err_free: free_cpumask_var(tracing_cpumask_new); return err; diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c index f5db30d25b0b..81d923c16a4d 100644 --- a/kernel/trace/trace_boot.c +++ b/kernel/trace/trace_boot.c @@ -18,6 +18,8 @@ extern int trace_set_options(struct trace_array *tr, char *option); extern int tracing_set_tracer(struct trace_array *tr, const char *buf); extern ssize_t tracing_resize_ring_buffer(struct trace_array *tr, unsigned long size, int cpu_id); +extern int tracing_set_cpumask(struct trace_array *tr, + cpumask_var_t tracing_cpumask_new); static void __init trace_boot_set_instance_options(struct trace_array *tr, struct xbc_node *node) @@ -52,6 +54,18 @@ trace_boot_set_instance_options(struct trace_array *tr, struct xbc_node *node) if (tracing_resize_ring_buffer(tr, v, RING_BUFFER_ALL_CPUS) < 0) pr_err("Failed to resize trace buffer to %s\n", p); } + + p = xbc_node_find_value(node, "cpumask", NULL); + if (p && *p != '\0') { + cpumask_var_t new_mask; + + if (alloc_cpumask_var(&new_mask, GFP_KERNEL)) { + if (cpumask_parse(p, new_mask) < 0 || + tracing_set_cpumask(tr, new_mask) < 0) + pr_err("Failed to set new CPU mask %s\n", p); + free_cpumask_var(new_mask); + } + } } #ifdef CONFIG_EVENT_TRACING |