From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: Mike Snitzer <snitzer@redhat.com>,
David Airlie <airlied@linux.ie>,
Catalin Marinas <catalin.marinas@arm.com>,
dri-devel@lists.freedesktop.org, linux-mm@kvack.org,
dm-devel@redhat.com, Alexander Potapenko <glider@google.com>,
Christoph Lameter <cl@linux.com>, Miroslav Benes <mbenes@suse.cz>,
Christoph Hellwig <hch@lst.de>, Alasdair Kergon <agk@redhat.com>,
Marek Szyprowski <m.szyprowski@samsung.com>,
linux-arch@vger.kernel.org, x86@kernel.org,
kasan-dev@googlegroups.com,
Johannes Thumshirn <jthumshirn@suse.de>,
Andrey Ryabinin <aryabinin@virtuozzo.com>,
Alexey Dobriyan <adobriyan@gmail.com>,
intel-gfx@lists.freedesktop.org,
David Rientjes <rientjes@google.com>,
Akinobu Mita <akinobu.mita@gmail.com>,
Steven Rostedt <rostedt@goodmis.org>,
Josef Bacik <josef@toxicpanda.com>,
Mike Rapoport <rppt@linux.vnet.ibm.com>,
Andy Lutomirski <luto@kernel.org>, Josh Poimboeuf <jpoimboe>
Subject: [patch V3 01/29] tracing: Cleanup stack trace code
Date: Thu, 25 Apr 2019 11:44:54 +0200 [thread overview]
Message-ID: <20190425094801.230654524@linutronix.de> (raw)
In-Reply-To: 20190425094453.875139013@linutronix.de
- Remove the extra array member of stack_dump_trace[] along with the
ARRAY_SIZE - 1 initialization for struct stack_trace :: max_entries.
Both are historical leftovers of no value. The stack tracer never exceeds
the array and there is no extra storage requirement either.
- Make variables which are only used in trace_stack.c static.
- Simplify the enable/disable logic.
- Rename stack_trace_print() as it's using the stack_trace_ namespace. Free
the name up for stack trace related functions.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
---
V3: Remove the -1 init and split the variable declaration as requested by Steven.
V2: Add more cleanups and use print_max_stack() as requested by Steven.
---
include/linux/ftrace.h | 18 ++++--------------
kernel/trace/trace_stack.c | 42 +++++++++++++-----------------------------
2 files changed, 17 insertions(+), 43 deletions(-)
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -241,21 +241,11 @@ static inline void ftrace_free_mem(struc
#ifdef CONFIG_STACK_TRACER
-#define STACK_TRACE_ENTRIES 500
-
-struct stack_trace;
-
-extern unsigned stack_trace_index[];
-extern struct stack_trace stack_trace_max;
-extern unsigned long stack_trace_max_size;
-extern arch_spinlock_t stack_trace_max_lock;
-
extern int stack_tracer_enabled;
-void stack_trace_print(void);
-int
-stack_trace_sysctl(struct ctl_table *table, int write,
- void __user *buffer, size_t *lenp,
- loff_t *ppos);
+
+int stack_trace_sysctl(struct ctl_table *table, int write,
+ void __user *buffer, size_t *lenp,
+ loff_t *ppos);
/* DO NOT MODIFY THIS VARIABLE DIRECTLY! */
DECLARE_PER_CPU(int, disable_stack_tracer);
--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -18,30 +18,26 @@
#include "trace.h"
-static unsigned long stack_dump_trace[STACK_TRACE_ENTRIES + 1];
-unsigned stack_trace_index[STACK_TRACE_ENTRIES];
+#define STACK_TRACE_ENTRIES 500
+
+static unsigned long stack_dump_trace[STACK_TRACE_ENTRIES];
+static unsigned stack_trace_index[STACK_TRACE_ENTRIES];
-/*
- * Reserve one entry for the passed in ip. This will allow
- * us to remove most or all of the stack size overhead
- * added by the stack tracer itself.
- */
struct stack_trace stack_trace_max = {
- .max_entries = STACK_TRACE_ENTRIES - 1,
+ .max_entries = STACK_TRACE_ENTRIES,
.entries = &stack_dump_trace[0],
};
-unsigned long stack_trace_max_size;
-arch_spinlock_t stack_trace_max_lock =
+static unsigned long stack_trace_max_size;
+static arch_spinlock_t stack_trace_max_lock =
(arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;
DEFINE_PER_CPU(int, disable_stack_tracer);
static DEFINE_MUTEX(stack_sysctl_mutex);
int stack_tracer_enabled;
-static int last_stack_tracer_enabled;
-void stack_trace_print(void)
+static void print_max_stack(void)
{
long i;
int size;
@@ -61,16 +57,7 @@ void stack_trace_print(void)
}
}
-/*
- * When arch-specific code overrides this function, the following
- * data should be filled up, assuming stack_trace_max_lock is held to
- * prevent concurrent updates.
- * stack_trace_index[]
- * stack_trace_max
- * stack_trace_max_size
- */
-void __weak
-check_stack(unsigned long ip, unsigned long *stack)
+static void check_stack(unsigned long ip, unsigned long *stack)
{
unsigned long this_size, flags; unsigned long *p, *top, *start;
static int tracer_frame;
@@ -179,7 +166,7 @@ check_stack(unsigned long ip, unsigned l
stack_trace_max.nr_entries = x;
if (task_stack_end_corrupted(current)) {
- stack_trace_print();
+ print_max_stack();
BUG();
}
@@ -412,23 +399,21 @@ stack_trace_sysctl(struct ctl_table *tab
void __user *buffer, size_t *lenp,
loff_t *ppos)
{
+ int was_enabled;
int ret;
mutex_lock(&stack_sysctl_mutex);
+ was_enabled = !!stack_tracer_enabled;
ret = proc_dointvec(table, write, buffer, lenp, ppos);
- if (ret || !write ||
- (last_stack_tracer_enabled == !!stack_tracer_enabled))
+ if (ret || !write || (was_enabled == !!stack_tracer_enabled))
goto out;
- last_stack_tracer_enabled = !!stack_tracer_enabled;
-
if (stack_tracer_enabled)
register_ftrace_function(&trace_ops);
else
unregister_ftrace_function(&trace_ops);
-
out:
mutex_unlock(&stack_sysctl_mutex);
return ret;
@@ -444,7 +429,6 @@ static __init int enable_stacktrace(char
strncpy(stack_trace_filter_buf, str + len, COMMAND_LINE_SIZE);
stack_tracer_enabled = 1;
- last_stack_tracer_enabled = 1;
return 1;
}
__setup("stacktrace", enable_stacktrace);
_______________________________________________
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Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
next prev parent reply other threads:[~2019-04-25 9:44 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-25 9:44 [patch V3 00/29] stacktrace: Consolidate stack trace usage Thomas Gleixner
2019-04-25 9:44 ` Thomas Gleixner [this message]
2019-04-25 9:44 ` [patch V3 02/29] stacktrace: Provide helpers for common stack trace operations Thomas Gleixner
2019-04-25 9:44 ` [patch V3 03/29] lib/stackdepot: Provide functions which operate on plain storage arrays Thomas Gleixner
2019-04-25 9:44 ` [patch V3 04/29] backtrace-test: Simplify stack trace handling Thomas Gleixner
2019-04-25 9:44 ` [patch V3 05/29] proc: Simplify task stack retrieval Thomas Gleixner
2019-04-25 9:44 ` [patch V3 06/29] latency_top: Simplify stack trace handling Thomas Gleixner
2019-04-25 9:45 ` [patch V3 07/29] mm/slub: Simplify stack trace retrieval Thomas Gleixner
2019-04-25 9:45 ` [patch V3 08/29] mm/kmemleak: Simplify stacktrace handling Thomas Gleixner
2019-04-25 9:45 ` [patch V3 09/29] mm/kasan: " Thomas Gleixner
2019-04-25 9:45 ` [patch V3 10/29] mm/page_owner: Simplify stack trace handling Thomas Gleixner
2019-04-25 9:45 ` [patch V3 11/29] fault-inject: Simplify stacktrace retrieval Thomas Gleixner
2019-04-25 9:45 ` [patch V3 12/29] dma/debug: Simplify stracktrace retrieval Thomas Gleixner
2019-04-25 9:45 ` [patch V3 13/29] btrfs: ref-verify: Simplify stack trace retrieval Thomas Gleixner
2019-04-25 9:45 ` [patch V3 14/29] dm bufio: " Thomas Gleixner
2019-04-25 9:45 ` [patch V3 15/29] dm persistent data: Simplify stack trace handling Thomas Gleixner
2019-04-25 9:45 ` [patch V3 16/29] drm: Simplify stacktrace handling Thomas Gleixner
2019-04-25 9:45 ` [patch V3 17/29] lockdep: Remove unused trace argument from print_circular_bug() Thomas Gleixner
2019-04-25 9:45 ` [patch V3 18/29] lockdep: Remove save argument from check_prev_add() Thomas Gleixner
2019-04-25 13:35 ` Peter Zijlstra
2019-04-25 9:45 ` [patch V3 19/29] lockdep: Simplify stack trace handling Thomas Gleixner
2019-04-25 9:45 ` [patch V3 20/29] tracing: Simplify stacktrace retrieval in histograms Thomas Gleixner
2019-04-25 9:45 ` [patch V3 21/29] tracing: Use percpu stack trace buffer more intelligently Thomas Gleixner
2019-04-25 13:29 ` Josh Poimboeuf
2019-04-25 9:45 ` [patch V3 22/29] tracing: Make ftrace_trace_userstack() static and conditional Thomas Gleixner
2019-04-25 9:45 ` [patch V3 23/29] tracing: Simplify stack trace retrieval Thomas Gleixner
2019-04-25 9:45 ` [patch V3 24/29] tracing: Remove the last struct stack_trace usage Thomas Gleixner
2019-04-25 13:30 ` Josh Poimboeuf
2019-04-25 9:45 ` [patch V3 25/29] livepatch: Simplify stack trace retrieval Thomas Gleixner
2019-04-25 9:45 ` [patch V3 26/29] stacktrace: Remove obsolete functions Thomas Gleixner
2019-04-25 9:45 ` [patch V3 27/29] lib/stackdepot: " Thomas Gleixner
2019-04-25 9:45 ` [patch V3 28/29] stacktrace: Provide common infrastructure Thomas Gleixner
2019-04-25 9:45 ` [patch V3 29/29] x86/stacktrace: Use " Thomas Gleixner
2019-04-25 10:09 ` [patch V3 00/29] stacktrace: Consolidate stack trace usage Ingo Molnar
2019-04-25 13:31 ` Josh Poimboeuf
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