* [PATCH v2] tracing: Fix trace_buf_size= cmdline parameter with sizes >= 2G
From: Calvin Owens @ 2026-03-07 3:19 UTC (permalink / raw)
To: linux-kernel, linux-trace-kernel
Cc: Steven Rostedt, Masami Hiramatsu, Mathieu Desnoyers
In-Reply-To: <20260306213730.566b9511@robin>
Some of the sizing logic through tracer_alloc_buffers() uses int
internally, causing unexpected behavior if the user passes a value that
does not fit in an int (on my x86 machine, the result is uselessly tiny
buffers).
Fix by plumbing the parameter's real type (unsigned long) through to the
ring buffer allocation functions, which already use unsigned long.
It has always been possible to create larger ring buffers via the sysfs
interface: this only affects the cmdline parameter.
Fixes: 73c5162aa362 ("tracing: keep ring buffer to minimum size till used")
Signed-off-by: Calvin Owens <calvin@wbinvd.org>
---
Changes in v2:
* Leave scratch_size as an int in allocate_trace_buffer(), undo callee
changes required after making it unsigned long [Steven]
kernel/trace/trace.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 1e7c032a72d2..ebd996f8710e 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -9350,7 +9350,7 @@ static void setup_trace_scratch(struct trace_array *tr,
}
static int
-allocate_trace_buffer(struct trace_array *tr, struct array_buffer *buf, int size)
+allocate_trace_buffer(struct trace_array *tr, struct array_buffer *buf, unsigned long size)
{
enum ring_buffer_flags rb_flags;
struct trace_scratch *tscratch;
@@ -9405,7 +9405,7 @@ static void free_trace_buffer(struct array_buffer *buf)
}
}
-static int allocate_trace_buffers(struct trace_array *tr, int size)
+static int allocate_trace_buffers(struct trace_array *tr, unsigned long size)
{
int ret;
@@ -10769,7 +10769,7 @@ __init static void enable_instances(void)
__init static int tracer_alloc_buffers(void)
{
- int ring_buf_size;
+ unsigned long ring_buf_size;
int ret = -ENOMEM;
--
2.47.3
^ permalink raw reply related
* Re: [PATCH] tracing: Fix trace_buf_size= cmdline parameter with sizes >= 2G
From: Steven Rostedt @ 2026-03-07 2:37 UTC (permalink / raw)
To: Calvin Owens
Cc: linux-kernel, linux-trace-kernel, Masami Hiramatsu,
Mathieu Desnoyers
In-Reply-To: <9a65e27b0394069040c9b8f8684525687dc15d6b.1772820006.git.calvin@wbinvd.org>
On Fri, 6 Mar 2026 18:28:38 -0800
Calvin Owens <calvin@wbinvd.org> wrote:
> Some of the sizing logic through tracer_alloc_buffers() uses int
> internally, causing unexpected behavior if the user passes a value that
> does not fit in an int (on my x86 machine, the result is uselessly tiny
> buffers).
>
> Fix by plumbing the parameter's real type (unsigned long) through to the
> ring buffer allocation functions, which already use unsigned long. Also,
> tweak ring_buffer_meta_scratch() to avoid void pointer arithmetic.
Let's make this only fix the problem at hand and leave scratch alone.
Scratch is seldom more than a page size and int should be plenty.
>
> It has always been possible to create larger ring buffers via the sysfs
> interface: this only affects the cmdline parameter.
>
> Fixes: 73c5162aa362 ("tracing: keep ring buffer to minimum size till used")
Another reason not to touch scratch, is because it's a very new
feature, and this fix goes back to 2009. If you want this to hit stable
trees, only fix what is needed.
Generally, you should only fix the problem anyway in one patch, and use
other patches to make other updates.
-- Steve
> Signed-off-by: Calvin Owens <calvin@wbinvd.org>
^ permalink raw reply
* [PATCH] tracing: Fix trace_buf_size= cmdline parameter with sizes >= 2G
From: Calvin Owens @ 2026-03-07 2:28 UTC (permalink / raw)
To: linux-kernel, linux-trace-kernel
Cc: Steven Rostedt, Masami Hiramatsu, Mathieu Desnoyers
Some of the sizing logic through tracer_alloc_buffers() uses int
internally, causing unexpected behavior if the user passes a value that
does not fit in an int (on my x86 machine, the result is uselessly tiny
buffers).
Fix by plumbing the parameter's real type (unsigned long) through to the
ring buffer allocation functions, which already use unsigned long. Also,
tweak ring_buffer_meta_scratch() to avoid void pointer arithmetic.
It has always been possible to create larger ring buffers via the sysfs
interface: this only affects the cmdline parameter.
Fixes: 73c5162aa362 ("tracing: keep ring buffer to minimum size till used")
Signed-off-by: Calvin Owens <calvin@wbinvd.org>
---
include/linux/ring_buffer.h | 3 ++-
kernel/trace/ring_buffer.c | 10 +++++-----
kernel/trace/trace.c | 13 +++++++------
3 files changed, 14 insertions(+), 12 deletions(-)
diff --git a/include/linux/ring_buffer.h b/include/linux/ring_buffer.h
index d862fa610270..c07eb463ca1c 100644
--- a/include/linux/ring_buffer.h
+++ b/include/linux/ring_buffer.h
@@ -95,7 +95,8 @@ struct trace_buffer *__ring_buffer_alloc_range(unsigned long size, unsigned flag
unsigned long scratch_size,
struct lock_class_key *key);
-void *ring_buffer_meta_scratch(struct trace_buffer *buffer, unsigned int *size);
+void *ring_buffer_meta_scratch(struct trace_buffer *buffer,
+ unsigned long *size);
/*
* Because the ring buffer is generic, if other users of the ring buffer get
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 17d0ea0cc3e6..30e579fd6b9d 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -2650,22 +2650,22 @@ struct trace_buffer *__ring_buffer_alloc_range(unsigned long size, unsigned flag
scratch_size, key);
}
-void *ring_buffer_meta_scratch(struct trace_buffer *buffer, unsigned int *size)
+void *ring_buffer_meta_scratch(struct trace_buffer *buffer, unsigned long *size)
{
struct ring_buffer_meta *meta;
- void *ptr;
+ unsigned long ptr;
if (!buffer || !buffer->meta)
return NULL;
meta = buffer->meta;
- ptr = (void *)ALIGN((unsigned long)meta + sizeof(*meta), sizeof(long));
+ ptr = ALIGN((unsigned long)meta + sizeof(*meta), sizeof(unsigned long));
if (size)
- *size = (void *)meta + meta->buffers_offset - ptr;
+ *size = (unsigned long)meta + meta->buffers_offset - ptr;
- return ptr;
+ return (void *)ptr;
}
/**
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 1e7c032a72d2..f6f5c44ddbf7 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -9282,11 +9282,12 @@ static int mod_addr_comp(const void *a, const void *b, const void *data)
}
static void setup_trace_scratch(struct trace_array *tr,
- struct trace_scratch *tscratch, unsigned int size)
+ struct trace_scratch *tscratch,
+ unsigned long size)
{
struct trace_module_delta *module_delta;
struct trace_mod_entry *entry;
- int i, nr_entries;
+ unsigned long i, nr_entries;
if (!tscratch)
return;
@@ -9350,11 +9351,11 @@ static void setup_trace_scratch(struct trace_array *tr,
}
static int
-allocate_trace_buffer(struct trace_array *tr, struct array_buffer *buf, int size)
+allocate_trace_buffer(struct trace_array *tr, struct array_buffer *buf, unsigned long size)
{
enum ring_buffer_flags rb_flags;
struct trace_scratch *tscratch;
- unsigned int scratch_size = 0;
+ unsigned long scratch_size = 0;
rb_flags = tr->trace_flags & TRACE_ITER(OVERWRITE) ? RB_FL_OVERWRITE : 0;
@@ -9405,7 +9406,7 @@ static void free_trace_buffer(struct array_buffer *buf)
}
}
-static int allocate_trace_buffers(struct trace_array *tr, int size)
+static int allocate_trace_buffers(struct trace_array *tr, unsigned long size)
{
int ret;
@@ -10769,7 +10770,7 @@ __init static void enable_instances(void)
__init static int tracer_alloc_buffers(void)
{
- int ring_buf_size;
+ unsigned long ring_buf_size;
int ret = -ENOMEM;
--
2.47.3
^ permalink raw reply related
* [PATCH] time/tracing: Make jiffies_64_to_clock_t() notrace
From: Steven Rostedt @ 2026-03-07 2:24 UTC (permalink / raw)
To: LKML, Linux trace kernel
Cc: Thomas Gleixner, Masami Hiramatsu, Mathieu Desnoyers, John Stultz
From: Steven Rostedt <rostedt@goodmis.org>
The trace_clock_jiffies() function that handles the "uptime" clock for
tracing calls jiffies_64_to_clock_t(). This causes the function tracer to
constantly recurse when the tracing clock is set to "uptime". Mark it
notrace to prevent unnecessary recursion when using the "uptime" clock.
Fixes: 58d4e21e50ff3 ("tracing: Fix wraparound problems in "uptime" trace clock")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
kernel/time/time.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/time/time.c b/kernel/time/time.c
index 36fd2313ae7e..0d832317d576 100644
--- a/kernel/time/time.c
+++ b/kernel/time/time.c
@@ -697,7 +697,7 @@ EXPORT_SYMBOL(clock_t_to_jiffies);
*
* Return: jiffies_64 value converted to 64-bit "clock_t" (CLOCKS_PER_SEC)
*/
-u64 jiffies_64_to_clock_t(u64 x)
+notrace u64 jiffies_64_to_clock_t(u64 x)
{
#if (TICK_NSEC % (NSEC_PER_SEC / USER_HZ)) == 0
# if HZ < USER_HZ
--
2.51.0
^ permalink raw reply related
* Re: [PATCH] tracing/osnoise: Add option to align tlat threads
From: Crystal Wood @ 2026-03-06 22:45 UTC (permalink / raw)
To: Tomas Glozar
Cc: Steven Rostedt, Masami Hiramatsu, Mathieu Desnoyers, John Kacur,
Luis Goncalves, Costa Shulyupin, Wander Lairson Costa, LKML,
linux-trace-kernel
In-Reply-To: <CAP4=nvSmbvz68H77T4Wohm7rT3Ojn_D_igBk8pvsvGurL05Kww@mail.gmail.com>
On Fri, 2026-03-06 at 16:15 +0100, Tomas Glozar wrote:
> út 3. 3. 2026 v 4:21 odesílatel Crystal Wood <crwood@redhat.com> napsal:
> > > 1. The wake-up timers are set to absolute time, and are incremented by
> > > "period" (once or multiple times, if the timer is significantly
> > > delayed) each cycle. What can be done as an alternative to what v1
> > > does is this: record the current time when starting the timerlat
> > > tracer (I need to reset align_next to zero anyway even with the v1
> > > design, that is a bug in the patch), and increment from that.
> >
> > I was only talking about doing this for the initial expiration, not on
> > increment.
> >
>
> Ah, I misread "period" as "relative period", since the initial
> absolute period is determined from the current time in the first cycle
> of each thread.
I did mean relative period ("absolute period" isn't a phrase that makes
sense to me; that's just an expiration); I just forgot to make the
"now +" part explicit.
> > > 2. "cpu" makes a poor thread ID here. If my period is 1000us, and I
> > > run on CPUs 0 and 100 with alignment 10, suddenly, the space between
> > > the threads becomes 1000us, which is equivalent to 0us. I would need
> > > to go through the cpuset and assign numbers from 0 to n to each CPU.
> > > That would guarantee a fixed spacing of the threads independent of
> > > when the threads wake up in the first cycle (unlike the v1 design),
> > > but it would make the implementation more complex, since I would have
> > > to store the numbers.
> >
> > Right, I was thinking of just a few CPUs missing not being a big deal,
> > but on big systems with only a few CPUs running the test it does
> > matter.
> >
>
> My point is mostly that the spacing of the threads shouldn't depend on
> the CPU numbers. One has to make sure the alignment doesn't overflow
> the period anyway if they want to have completely time-isolated
> wake-ups.
Yeah, I underestimated how easy it would be for that to be a problem. I
think this is a good enough reason to use the atomic approach.
> The while loop is designed only to handle "small" time differences,
> with respect to the relative period. When using timerlat manually with
> a user workload, it might take the user a few seconds/seconds/hours
> before they start the user process (typing the command line, or if the
> user e.g. has a snack or coffee in between), which has to be corrected
> by the while loop. This does not interact well with a low period.
> Consider the following scenario, assuming the initial absolute period
> is set on timerlat tracer enablement:
>
> 1. The user enables the timerlat tracer with NO_OSNOISE_WORKLOAD and
> 100us period.
> 2. The user steps away for 1 hour.
> 3. After 10 seconds, tlat->abs_period is 3 600 000 000us in the past.
> The while loop starts incrementing tlat->abs_period by 100us, taking
> 36 000 000 loops. If one iteration takes 10 CPU cycles on a 1GHz CPU,
> the while loop itself will take 360us (which is >100us).
> 4. The timerlat thread never wakes up, since the wake-up time even
> after the correction is in the past.
(assuming you meant "after one hour" instead of 10 seconds)
Oh, I see it doesn't update "now" inside the loop. Arming a timer for
the past should cause it to fire immediately though; otherwise there
would be all sorts of nasty races.
In any case, regardless of what we do with alignment, we could simplify
by replacing the while loop with hrtimer_forward_now() which does
division (if necessary) instead of a loop, and get rid of
tlat->abs_period (the handler can call hrtimer_get_expires()).
> This is much more reasonable than the user stopping the thread inside
> the while loop. Actually, this scenario can already happen without
> alignment, since the scheduler might preempt the thread inside the
> while loop for more than the period - but that is a separate issue.
>
> Also, the current implementation is relatively simple (and hopefully
> also easy to understand with the comments in v2), so my idea is that
> we can use it for now, and if we want deterministing alignment in the
> future, we can always improve it.
The comments do help, thanks. v1 took me a few tries to figure out,
given how different it is from usual cmpxchg usage. v2 looks good to
me.
> > > I used it in cyclictest to measure the overhead of a large number of
> > > threads waking up at the same time. Similarly, a non-zero alignment
> > > will get rid of most of that overhead. Without alignment set, the
> > > thread wake-ups offsets are semi-random, depending on how the threads
> > > wake up, which might lead to inconsistent results where one run has
> > > good numbers and another run bad numbers, since the alignment is
> > > determined in the first cycle.
> >
> > OK, I was viewing the staggering as the main point, but I see how the
> > alignment itself helps too.
> >
> > Is there a use case for not always doing the alignment?
> > Other than people asking why their numbers suddenly got worse...
> >
>
> Yes - to simulate the default behavior of cyclictest without
> -A/--aligned, and of multi-thread cyclic workloads that do not align
> their threads respectively. Even if we wanted to always use the
> alignment, it should not default to 0 IMHO, so that users don't see a
> degradation like you mention.
It just feels a bit weird to preserve "maybe they're bunched up, maybe
not, who knows?" as a feature (much less the default), especially for a
tool meant to help with determinism.
> > Why can't we just make tlat->abs_period and every other time variable
> > in this file be ktime_t? Other than atomic stuff if we do go that
> > route.
> >
> > Not saying that that should hold up this patch, just an idea to simplify things.
> >
>
> The reason for that is that the code does arithmetic directly on the
> ns unit form of the time, without the need to use ktime_add(). I don't
> see anything on top of that. I see ktime_add(x, y) is just x + y
> nowadays, so that would work.
We should still use ktime_add() etc. in order to be nice users of the
interface. I just think the conversions are worse clutter than a
couple ktime add/sub calls.
-Crystal
^ permalink raw reply
* Re: [PATCH v3] tracefs: Use dentry name snapshots instead of heap allocation
From: Steven Rostedt @ 2026-03-06 21:41 UTC (permalink / raw)
To: AnishMulay
Cc: viro, mhiramat, mathieu.desnoyers, linux-trace-kernel,
linux-kernel
In-Reply-To: <20260306200458.2264-1-anishm7030@gmail.com>
On Fri, 6 Mar 2026 15:04:58 -0500
AnishMulay <anishm7030@gmail.com> wrote:
Thanks for the update, but please do not have a new patch as a reply to the
old one. It makes it harder to find. As I'll only look at top level emails
for patches in my inbox which means all new versions should be their own
thread.
> In fs/tracefs/inode.c, tracefs_syscall_mkdir() and tracefs_syscall_rmdir()
> previously used a local helper, get_dname(), which allocated a temporary
> buffer on the heap via kmalloc() to hold the dentry name. This introduced
> unnecessary overhead, an ENOMEM failure path, and required manual memory
> cleanup via kfree().
>
> As suggested by Al Viro, replace this heap allocation with the VFS dentry
> name snapshot API. By stack-allocating a `struct name_snapshot` and using
> take_dentry_name_snapshot() and release_dentry_name_snapshot(), we safely
> capture the dentry name locklessly, eliminate the heap allocation entirely,
> and remove the now-obsolete error handling paths. The get_dname() helper
> is completely removed.
>
> Testing:
> Booted a custom kernel natively in virtme-ng (ARM64). Triggered tracefs
> inode and dentry allocation by creating and removing a custom directory
> under a temporary tracefs mount. Verified that the instance is created
> successfully and that no memory errors or warnings are emitted in dmesg.
>
> Signed-off-by: AnishMulay <anishm7030@gmail.com>
> ---
> Changes in v3:
The above should have been:
Changes since v2: https://lore.kernel.org/all/20260227211505.226643-1-anishm7030@gmail.com/
> - Rebased into a single clean commit against upstream.
>
> Changes in v2:
> - Link to v1: https://lore.kernel.org/linux-trace-kernel/20260227194453.213095-1-anishm7030@gmail.com/
> - Use the helper functions take/release_dentry_name_snapshot() instead of allocating the name. (Al Viro)
The above isn't needed as the above link will give it to you.
No need to resend (unless I find something wrong with the code of the
patch).
-- Steve
^ permalink raw reply
* [PATCH v3] tracefs: Use dentry name snapshots instead of heap allocation
From: AnishMulay @ 2026-03-06 20:04 UTC (permalink / raw)
To: rostedt, viro
Cc: mhiramat, mathieu.desnoyers, linux-trace-kernel, linux-kernel,
AnishMulay
In-Reply-To: <20260305165231.67c2491d@gandalf.local.home>
In fs/tracefs/inode.c, tracefs_syscall_mkdir() and tracefs_syscall_rmdir()
previously used a local helper, get_dname(), which allocated a temporary
buffer on the heap via kmalloc() to hold the dentry name. This introduced
unnecessary overhead, an ENOMEM failure path, and required manual memory
cleanup via kfree().
As suggested by Al Viro, replace this heap allocation with the VFS dentry
name snapshot API. By stack-allocating a `struct name_snapshot` and using
take_dentry_name_snapshot() and release_dentry_name_snapshot(), we safely
capture the dentry name locklessly, eliminate the heap allocation entirely,
and remove the now-obsolete error handling paths. The get_dname() helper
is completely removed.
Testing:
Booted a custom kernel natively in virtme-ng (ARM64). Triggered tracefs
inode and dentry allocation by creating and removing a custom directory
under a temporary tracefs mount. Verified that the instance is created
successfully and that no memory errors or warnings are emitted in dmesg.
Signed-off-by: AnishMulay <anishm7030@gmail.com>
---
Changes in v3:
- Rebased into a single clean commit against upstream.
Changes in v2:
- Link to v1: https://lore.kernel.org/linux-trace-kernel/20260227194453.213095-1-anishm7030@gmail.com/
- Use the helper functions take/release_dentry_name_snapshot() instead of allocating the name. (Al Viro)
fs/tracefs/inode.c | 39 ++++++++-------------------------------
1 file changed, 8 insertions(+), 31 deletions(-)
diff --git a/fs/tracefs/inode.c b/fs/tracefs/inode.c
index d9d8932a7b9c9..ad322e8f9e2ad 100644
--- a/fs/tracefs/inode.c
+++ b/fs/tracefs/inode.c
@@ -94,33 +94,14 @@ static struct tracefs_dir_ops {
int (*rmdir)(const char *name);
} tracefs_ops __ro_after_init;
-static char *get_dname(struct dentry *dentry)
-{
- const char *dname;
- char *name;
- int len = dentry->d_name.len;
-
- dname = dentry->d_name.name;
- name = kmalloc(len + 1, GFP_KERNEL);
- if (!name)
- return NULL;
- memcpy(name, dname, len);
- name[len] = 0;
- return name;
-}
-
static struct dentry *tracefs_syscall_mkdir(struct mnt_idmap *idmap,
struct inode *inode, struct dentry *dentry,
umode_t mode)
{
struct tracefs_inode *ti;
- char *name;
+ struct name_snapshot name;
int ret;
- name = get_dname(dentry);
- if (!name)
- return ERR_PTR(-ENOMEM);
-
/*
* This is a new directory that does not take the default of
* the rootfs. It becomes the default permissions for all the
@@ -135,24 +116,20 @@ static struct dentry *tracefs_syscall_mkdir(struct mnt_idmap *idmap,
* the files within the tracefs system. It is up to the individual
* mkdir routine to handle races.
*/
+ take_dentry_name_snapshot(&name, dentry);
inode_unlock(inode);
- ret = tracefs_ops.mkdir(name);
+ ret = tracefs_ops.mkdir(name.name.name);
inode_lock(inode);
-
- kfree(name);
+ release_dentry_name_snapshot(&name);
return ERR_PTR(ret);
}
static int tracefs_syscall_rmdir(struct inode *inode, struct dentry *dentry)
{
- char *name;
+ struct name_snapshot name;
int ret;
- name = get_dname(dentry);
- if (!name)
- return -ENOMEM;
-
/*
* The rmdir call can call the generic functions that create
* the files within the tracefs system. It is up to the individual
@@ -160,15 +137,15 @@ static int tracefs_syscall_rmdir(struct inode *inode, struct dentry *dentry)
* This time we need to unlock not only the parent (inode) but
* also the directory that is being deleted.
*/
+ take_dentry_name_snapshot(&name, dentry);
inode_unlock(inode);
inode_unlock(d_inode(dentry));
- ret = tracefs_ops.rmdir(name);
+ ret = tracefs_ops.rmdir(name.name.name);
inode_lock_nested(inode, I_MUTEX_PARENT);
inode_lock(d_inode(dentry));
-
- kfree(name);
+ release_dentry_name_snapshot(&name);
return ret;
}
--
2.51.0
^ permalink raw reply related
* [PATCH v4 4/4] tools/rtla: Remove unneeded nr_cpus from for_each_monitored_cpu
From: Costa Shulyupin @ 2026-03-06 19:49 UTC (permalink / raw)
To: Steven Rostedt, Tomas Glozar, Costa Shulyupin, Crystal Wood,
Wander Lairson Costa, John Kacur, Ivan Pravdin, Tiezhu Yang,
linux-trace-kernel, linux-kernel, bpf
In-Reply-To: <20260306194953.2511960-1-costa.shul@redhat.com>
nr_cpus does not change at runtime, so passing it through the macro
argument is unnecessary.
Remove the argument and use the global nr_cpus instead.
Signed-off-by: Costa Shulyupin <costa.shul@redhat.com>
---
tools/tracing/rtla/src/common.h | 2 +-
tools/tracing/rtla/src/osnoise_hist.c | 15 +++++++--------
tools/tracing/rtla/src/osnoise_top.c | 2 +-
tools/tracing/rtla/src/timerlat.c | 4 ++--
tools/tracing/rtla/src/timerlat_hist.c | 16 ++++++++--------
tools/tracing/rtla/src/timerlat_top.c | 2 +-
6 files changed, 20 insertions(+), 21 deletions(-)
diff --git a/tools/tracing/rtla/src/common.h b/tools/tracing/rtla/src/common.h
index 90a3c0d1dbf3..22ec436a93cc 100644
--- a/tools/tracing/rtla/src/common.h
+++ b/tools/tracing/rtla/src/common.h
@@ -110,7 +110,7 @@ struct common_params {
extern int nr_cpus;
-#define for_each_monitored_cpu(cpu, nr_cpus, common) \
+#define for_each_monitored_cpu(cpu, common) \
for (cpu = 0; cpu < nr_cpus; cpu++) \
if (!(common)->cpus || CPU_ISSET(cpu, &(common)->monitored_cpus))
diff --git a/tools/tracing/rtla/src/osnoise_hist.c b/tools/tracing/rtla/src/osnoise_hist.c
index 5bbec27b46a7..4181e025511a 100644
--- a/tools/tracing/rtla/src/osnoise_hist.c
+++ b/tools/tracing/rtla/src/osnoise_hist.c
@@ -244,7 +244,7 @@ static void osnoise_hist_header(struct osnoise_tool *tool)
if (!params->common.hist.no_index)
trace_seq_printf(s, "Index");
- for_each_monitored_cpu(cpu, nr_cpus, ¶ms->common) {
+ for_each_monitored_cpu(cpu, ¶ms->common) {
if (!data->hist[cpu].count)
continue;
@@ -273,8 +273,7 @@ osnoise_print_summary(struct osnoise_params *params,
if (!params->common.hist.no_index)
trace_seq_printf(trace->seq, "count:");
- for_each_monitored_cpu(cpu, nr_cpus, ¶ms->common) {
-
+ for_each_monitored_cpu(cpu, ¶ms->common) {
if (!data->hist[cpu].count)
continue;
@@ -285,7 +284,7 @@ osnoise_print_summary(struct osnoise_params *params,
if (!params->common.hist.no_index)
trace_seq_printf(trace->seq, "min: ");
- for_each_monitored_cpu(cpu, nr_cpus, ¶ms->common) {
+ for_each_monitored_cpu(cpu, ¶ms->common) {
if (!data->hist[cpu].count)
continue;
@@ -298,7 +297,7 @@ osnoise_print_summary(struct osnoise_params *params,
if (!params->common.hist.no_index)
trace_seq_printf(trace->seq, "avg: ");
- for_each_monitored_cpu(cpu, nr_cpus, ¶ms->common) {
+ for_each_monitored_cpu(cpu, ¶ms->common) {
if (!data->hist[cpu].count)
continue;
@@ -314,7 +313,7 @@ osnoise_print_summary(struct osnoise_params *params,
if (!params->common.hist.no_index)
trace_seq_printf(trace->seq, "max: ");
- for_each_monitored_cpu(cpu, nr_cpus, ¶ms->common) {
+ for_each_monitored_cpu(cpu, ¶ms->common) {
if (!data->hist[cpu].count)
continue;
@@ -349,7 +348,7 @@ osnoise_print_stats(struct osnoise_tool *tool)
trace_seq_printf(trace->seq, "%-6d",
bucket * data->bucket_size);
- for_each_monitored_cpu(cpu, nr_cpus, ¶ms->common) {
+ for_each_monitored_cpu(cpu, ¶ms->common) {
if (!data->hist[cpu].count)
continue;
@@ -385,7 +384,7 @@ osnoise_print_stats(struct osnoise_tool *tool)
if (!params->common.hist.no_index)
trace_seq_printf(trace->seq, "over: ");
- for_each_monitored_cpu(cpu, nr_cpus, ¶ms->common) {
+ for_each_monitored_cpu(cpu, ¶ms->common) {
if (!data->hist[cpu].count)
continue;
diff --git a/tools/tracing/rtla/src/osnoise_top.c b/tools/tracing/rtla/src/osnoise_top.c
index 672cdb254f4c..f92caea9f2e9 100644
--- a/tools/tracing/rtla/src/osnoise_top.c
+++ b/tools/tracing/rtla/src/osnoise_top.c
@@ -236,7 +236,7 @@ osnoise_print_stats(struct osnoise_tool *top)
osnoise_top_header(top);
- for_each_monitored_cpu(i, nr_cpus, ¶ms->common) {
+ for_each_monitored_cpu(i, ¶ms->common) {
osnoise_top_print(top, i);
}
diff --git a/tools/tracing/rtla/src/timerlat.c b/tools/tracing/rtla/src/timerlat.c
index 31c921efa7c1..8a44537e25cb 100644
--- a/tools/tracing/rtla/src/timerlat.c
+++ b/tools/tracing/rtla/src/timerlat.c
@@ -115,7 +115,7 @@ int timerlat_enable(struct osnoise_tool *tool)
return -1;
}
- for_each_monitored_cpu(i, nr_cpus, ¶ms->common) {
+ for_each_monitored_cpu(i, ¶ms->common) {
if (save_cpu_idle_disable_state(i) < 0) {
err_msg("Could not save cpu idle state.\n");
return -1;
@@ -218,7 +218,7 @@ void timerlat_free(struct osnoise_tool *tool)
if (dma_latency_fd >= 0)
close(dma_latency_fd);
if (params->deepest_idle_state >= -1) {
- for_each_monitored_cpu(i, nr_cpus, ¶ms->common) {
+ for_each_monitored_cpu(i, ¶ms->common) {
restore_cpu_idle_disable_state(i);
}
}
diff --git a/tools/tracing/rtla/src/timerlat_hist.c b/tools/tracing/rtla/src/timerlat_hist.c
index cfb745b75b8a..ee1af251c94d 100644
--- a/tools/tracing/rtla/src/timerlat_hist.c
+++ b/tools/tracing/rtla/src/timerlat_hist.c
@@ -298,7 +298,7 @@ static void timerlat_hist_header(struct osnoise_tool *tool)
if (!params->common.hist.no_index)
trace_seq_printf(s, "Index");
- for_each_monitored_cpu(cpu, nr_cpus, ¶ms->common) {
+ for_each_monitored_cpu(cpu, ¶ms->common) {
if (!data->hist[cpu].irq_count && !data->hist[cpu].thread_count)
continue;
@@ -350,7 +350,7 @@ timerlat_print_summary(struct timerlat_params *params,
if (!params->common.hist.no_index)
trace_seq_printf(trace->seq, "count:");
- for_each_monitored_cpu(cpu, nr_cpus, ¶ms->common) {
+ for_each_monitored_cpu(cpu, ¶ms->common) {
if (!data->hist[cpu].irq_count && !data->hist[cpu].thread_count)
continue;
@@ -372,7 +372,7 @@ timerlat_print_summary(struct timerlat_params *params,
if (!params->common.hist.no_index)
trace_seq_printf(trace->seq, "min: ");
- for_each_monitored_cpu(cpu, nr_cpus, ¶ms->common) {
+ for_each_monitored_cpu(cpu, ¶ms->common) {
if (!data->hist[cpu].irq_count && !data->hist[cpu].thread_count)
continue;
@@ -400,7 +400,7 @@ timerlat_print_summary(struct timerlat_params *params,
if (!params->common.hist.no_index)
trace_seq_printf(trace->seq, "avg: ");
- for_each_monitored_cpu(cpu, nr_cpus, ¶ms->common) {
+ for_each_monitored_cpu(cpu, ¶ms->common) {
if (!data->hist[cpu].irq_count && !data->hist[cpu].thread_count)
continue;
@@ -428,7 +428,7 @@ timerlat_print_summary(struct timerlat_params *params,
if (!params->common.hist.no_index)
trace_seq_printf(trace->seq, "max: ");
- for_each_monitored_cpu(cpu, nr_cpus, ¶ms->common) {
+ for_each_monitored_cpu(cpu, ¶ms->common) {
if (!data->hist[cpu].irq_count && !data->hist[cpu].thread_count)
continue;
@@ -473,7 +473,7 @@ timerlat_print_stats_all(struct timerlat_params *params,
sum.min_thread = ~0;
sum.min_user = ~0;
- for_each_monitored_cpu(cpu, nr_cpus, ¶ms->common) {
+ for_each_monitored_cpu(cpu, ¶ms->common) {
if (!data->hist[cpu].irq_count && !data->hist[cpu].thread_count)
continue;
@@ -620,7 +620,7 @@ timerlat_print_stats(struct osnoise_tool *tool)
trace_seq_printf(trace->seq, "%-6d",
bucket * data->bucket_size);
- for_each_monitored_cpu(cpu, nr_cpus, ¶ms->common) {
+ for_each_monitored_cpu(cpu, ¶ms->common) {
if (!data->hist[cpu].irq_count && !data->hist[cpu].thread_count)
continue;
@@ -658,7 +658,7 @@ timerlat_print_stats(struct osnoise_tool *tool)
if (!params->common.hist.no_index)
trace_seq_printf(trace->seq, "over: ");
- for_each_monitored_cpu(cpu, nr_cpus, ¶ms->common) {
+ for_each_monitored_cpu(cpu, ¶ms->common) {
if (!data->hist[cpu].irq_count && !data->hist[cpu].thread_count)
continue;
diff --git a/tools/tracing/rtla/src/timerlat_top.c b/tools/tracing/rtla/src/timerlat_top.c
index 8fad4edb0d72..cc296c9d7fe7 100644
--- a/tools/tracing/rtla/src/timerlat_top.c
+++ b/tools/tracing/rtla/src/timerlat_top.c
@@ -446,7 +446,7 @@ timerlat_print_stats(struct osnoise_tool *top)
timerlat_top_header(params, top);
- for_each_monitored_cpu(i, nr_cpus, ¶ms->common) {
+ for_each_monitored_cpu(i, ¶ms->common) {
timerlat_top_print(top, i);
timerlat_top_update_sum(top, i, &summary);
}
--
2.53.0
^ permalink raw reply related
* [PATCH v4 3/4] tools/rtla: Remove unneeded nr_cpus members
From: Costa Shulyupin @ 2026-03-06 19:49 UTC (permalink / raw)
To: Steven Rostedt, Tomas Glozar, Costa Shulyupin, Crystal Wood,
Wander Lairson Costa, John Kacur, Ivan Pravdin, Tiezhu Yang,
linux-trace-kernel, linux-kernel, bpf
In-Reply-To: <20260306194953.2511960-1-costa.shul@redhat.com>
nr_cpus does not change at runtime, so keeping it in struct members is
unnecessary.
Use the global nr_cpus instead of struct members.
Signed-off-by: Costa Shulyupin <costa.shul@redhat.com>
---
tools/tracing/rtla/src/osnoise_hist.c | 18 ++++++------
tools/tracing/rtla/src/osnoise_top.c | 3 --
tools/tracing/rtla/src/timerlat_aa.c | 10 +++----
tools/tracing/rtla/src/timerlat_hist.c | 38 ++++++++++++--------------
tools/tracing/rtla/src/timerlat_top.c | 19 ++++++-------
5 files changed, 38 insertions(+), 50 deletions(-)
diff --git a/tools/tracing/rtla/src/osnoise_hist.c b/tools/tracing/rtla/src/osnoise_hist.c
index f39f60d3b00e..5bbec27b46a7 100644
--- a/tools/tracing/rtla/src/osnoise_hist.c
+++ b/tools/tracing/rtla/src/osnoise_hist.c
@@ -29,7 +29,6 @@ struct osnoise_hist_data {
struct osnoise_hist_cpu *hist;
int entries;
int bucket_size;
- int nr_cpus;
};
/*
@@ -41,7 +40,7 @@ osnoise_free_histogram(struct osnoise_hist_data *data)
int cpu;
/* one histogram for IRQ and one for thread, per CPU */
- for (cpu = 0; cpu < data->nr_cpus; cpu++) {
+ for (cpu = 0; cpu < nr_cpus; cpu++) {
if (data->hist[cpu].samples)
free(data->hist[cpu].samples);
}
@@ -73,7 +72,6 @@ static struct osnoise_hist_data
data->entries = entries;
data->bucket_size = bucket_size;
- data->nr_cpus = nr_cpus;
data->hist = calloc(1, sizeof(*data->hist) * nr_cpus);
if (!data->hist)
@@ -246,7 +244,7 @@ static void osnoise_hist_header(struct osnoise_tool *tool)
if (!params->common.hist.no_index)
trace_seq_printf(s, "Index");
- for_each_monitored_cpu(cpu, data->nr_cpus, ¶ms->common) {
+ for_each_monitored_cpu(cpu, nr_cpus, ¶ms->common) {
if (!data->hist[cpu].count)
continue;
@@ -275,7 +273,7 @@ osnoise_print_summary(struct osnoise_params *params,
if (!params->common.hist.no_index)
trace_seq_printf(trace->seq, "count:");
- for_each_monitored_cpu(cpu, data->nr_cpus, ¶ms->common) {
+ for_each_monitored_cpu(cpu, nr_cpus, ¶ms->common) {
if (!data->hist[cpu].count)
continue;
@@ -287,7 +285,7 @@ osnoise_print_summary(struct osnoise_params *params,
if (!params->common.hist.no_index)
trace_seq_printf(trace->seq, "min: ");
- for_each_monitored_cpu(cpu, data->nr_cpus, ¶ms->common) {
+ for_each_monitored_cpu(cpu, nr_cpus, ¶ms->common) {
if (!data->hist[cpu].count)
continue;
@@ -300,7 +298,7 @@ osnoise_print_summary(struct osnoise_params *params,
if (!params->common.hist.no_index)
trace_seq_printf(trace->seq, "avg: ");
- for_each_monitored_cpu(cpu, data->nr_cpus, ¶ms->common) {
+ for_each_monitored_cpu(cpu, nr_cpus, ¶ms->common) {
if (!data->hist[cpu].count)
continue;
@@ -316,7 +314,7 @@ osnoise_print_summary(struct osnoise_params *params,
if (!params->common.hist.no_index)
trace_seq_printf(trace->seq, "max: ");
- for_each_monitored_cpu(cpu, data->nr_cpus, ¶ms->common) {
+ for_each_monitored_cpu(cpu, nr_cpus, ¶ms->common) {
if (!data->hist[cpu].count)
continue;
@@ -351,7 +349,7 @@ osnoise_print_stats(struct osnoise_tool *tool)
trace_seq_printf(trace->seq, "%-6d",
bucket * data->bucket_size);
- for_each_monitored_cpu(cpu, data->nr_cpus, ¶ms->common) {
+ for_each_monitored_cpu(cpu, nr_cpus, ¶ms->common) {
if (!data->hist[cpu].count)
continue;
@@ -387,7 +385,7 @@ osnoise_print_stats(struct osnoise_tool *tool)
if (!params->common.hist.no_index)
trace_seq_printf(trace->seq, "over: ");
- for_each_monitored_cpu(cpu, data->nr_cpus, ¶ms->common) {
+ for_each_monitored_cpu(cpu, nr_cpus, ¶ms->common) {
if (!data->hist[cpu].count)
continue;
diff --git a/tools/tracing/rtla/src/osnoise_top.c b/tools/tracing/rtla/src/osnoise_top.c
index 3a241b69f622..672cdb254f4c 100644
--- a/tools/tracing/rtla/src/osnoise_top.c
+++ b/tools/tracing/rtla/src/osnoise_top.c
@@ -31,7 +31,6 @@ struct osnoise_top_cpu {
struct osnoise_top_data {
struct osnoise_top_cpu *cpu_data;
- int nr_cpus;
};
/*
@@ -59,8 +58,6 @@ static struct osnoise_top_data *osnoise_alloc_top(void)
if (!data)
return NULL;
- data->nr_cpus = nr_cpus;
-
/* one set of histograms per CPU */
data->cpu_data = calloc(1, sizeof(*data->cpu_data) * nr_cpus);
if (!data->cpu_data)
diff --git a/tools/tracing/rtla/src/timerlat_aa.c b/tools/tracing/rtla/src/timerlat_aa.c
index 095483375823..41d8d48c5b41 100644
--- a/tools/tracing/rtla/src/timerlat_aa.c
+++ b/tools/tracing/rtla/src/timerlat_aa.c
@@ -102,7 +102,6 @@ struct timerlat_aa_data {
* The analysis context and system wide view
*/
struct timerlat_aa_context {
- int nr_cpus;
int dump_tasks;
enum stack_format stack_format;
@@ -759,7 +758,7 @@ void timerlat_auto_analysis(int irq_thresh, int thread_thresh)
irq_thresh = irq_thresh * 1000;
thread_thresh = thread_thresh * 1000;
- for (cpu = 0; cpu < taa_ctx->nr_cpus; cpu++) {
+ for (cpu = 0; cpu < nr_cpus; cpu++) {
taa_data = timerlat_aa_get_data(taa_ctx, cpu);
if (irq_thresh && taa_data->tlat_irq_latency >= irq_thresh) {
@@ -787,7 +786,7 @@ void timerlat_auto_analysis(int irq_thresh, int thread_thresh)
printf("\n");
printf("Printing CPU tasks:\n");
- for (cpu = 0; cpu < taa_ctx->nr_cpus; cpu++) {
+ for (cpu = 0; cpu < nr_cpus; cpu++) {
taa_data = timerlat_aa_get_data(taa_ctx, cpu);
tep = taa_ctx->tool->trace.tep;
@@ -813,7 +812,7 @@ static void timerlat_aa_destroy_seqs(struct timerlat_aa_context *taa_ctx)
if (!taa_ctx->taa_data)
return;
- for (i = 0; i < taa_ctx->nr_cpus; i++) {
+ for (i = 0; i < nr_cpus; i++) {
taa_data = timerlat_aa_get_data(taa_ctx, i);
if (taa_data->prev_irqs_seq) {
@@ -863,7 +862,7 @@ static int timerlat_aa_init_seqs(struct timerlat_aa_context *taa_ctx)
struct timerlat_aa_data *taa_data;
int i;
- for (i = 0; i < taa_ctx->nr_cpus; i++) {
+ for (i = 0; i < nr_cpus; i++) {
taa_data = timerlat_aa_get_data(taa_ctx, i);
@@ -1052,7 +1051,6 @@ int timerlat_aa_init(struct osnoise_tool *tool, int dump_tasks, enum stack_forma
__timerlat_aa_ctx = taa_ctx;
- taa_ctx->nr_cpus = nr_cpus;
taa_ctx->tool = tool;
taa_ctx->dump_tasks = dump_tasks;
taa_ctx->stack_format = stack_format;
diff --git a/tools/tracing/rtla/src/timerlat_hist.c b/tools/tracing/rtla/src/timerlat_hist.c
index 7e735b62488c..cfb745b75b8a 100644
--- a/tools/tracing/rtla/src/timerlat_hist.c
+++ b/tools/tracing/rtla/src/timerlat_hist.c
@@ -44,7 +44,6 @@ struct timerlat_hist_data {
struct timerlat_hist_cpu *hist;
int entries;
int bucket_size;
- int nr_cpus;
};
/*
@@ -56,7 +55,7 @@ timerlat_free_histogram(struct timerlat_hist_data *data)
int cpu;
/* one histogram for IRQ and one for thread, per CPU */
- for (cpu = 0; cpu < data->nr_cpus; cpu++) {
+ for (cpu = 0; cpu < nr_cpus; cpu++) {
if (data->hist[cpu].irq)
free(data->hist[cpu].irq);
@@ -94,7 +93,6 @@ static struct timerlat_hist_data
data->entries = entries;
data->bucket_size = bucket_size;
- data->nr_cpus = nr_cpus;
/* one set of histograms per CPU */
data->hist = calloc(1, sizeof(*data->hist) * nr_cpus);
@@ -204,9 +202,9 @@ static int timerlat_hist_bpf_pull_data(struct osnoise_tool *tool)
{
struct timerlat_hist_data *data = tool->data;
int i, j, err;
- long long value_irq[data->nr_cpus],
- value_thread[data->nr_cpus],
- value_user[data->nr_cpus];
+ long long value_irq[nr_cpus],
+ value_thread[nr_cpus],
+ value_user[nr_cpus];
/* Pull histogram */
for (i = 0; i < data->entries; i++) {
@@ -214,7 +212,7 @@ static int timerlat_hist_bpf_pull_data(struct osnoise_tool *tool)
value_user);
if (err)
return err;
- for (j = 0; j < data->nr_cpus; j++) {
+ for (j = 0; j < nr_cpus; j++) {
data->hist[j].irq[i] = value_irq[j];
data->hist[j].thread[i] = value_thread[j];
data->hist[j].user[i] = value_user[j];
@@ -226,7 +224,7 @@ static int timerlat_hist_bpf_pull_data(struct osnoise_tool *tool)
value_irq, value_thread, value_user);
if (err)
return err;
- for (i = 0; i < data->nr_cpus; i++) {
+ for (i = 0; i < nr_cpus; i++) {
data->hist[i].irq_count = value_irq[i];
data->hist[i].thread_count = value_thread[i];
data->hist[i].user_count = value_user[i];
@@ -236,7 +234,7 @@ static int timerlat_hist_bpf_pull_data(struct osnoise_tool *tool)
value_irq, value_thread, value_user);
if (err)
return err;
- for (i = 0; i < data->nr_cpus; i++) {
+ for (i = 0; i < nr_cpus; i++) {
data->hist[i].min_irq = value_irq[i];
data->hist[i].min_thread = value_thread[i];
data->hist[i].min_user = value_user[i];
@@ -246,7 +244,7 @@ static int timerlat_hist_bpf_pull_data(struct osnoise_tool *tool)
value_irq, value_thread, value_user);
if (err)
return err;
- for (i = 0; i < data->nr_cpus; i++) {
+ for (i = 0; i < nr_cpus; i++) {
data->hist[i].max_irq = value_irq[i];
data->hist[i].max_thread = value_thread[i];
data->hist[i].max_user = value_user[i];
@@ -256,7 +254,7 @@ static int timerlat_hist_bpf_pull_data(struct osnoise_tool *tool)
value_irq, value_thread, value_user);
if (err)
return err;
- for (i = 0; i < data->nr_cpus; i++) {
+ for (i = 0; i < nr_cpus; i++) {
data->hist[i].sum_irq = value_irq[i];
data->hist[i].sum_thread = value_thread[i];
data->hist[i].sum_user = value_user[i];
@@ -266,7 +264,7 @@ static int timerlat_hist_bpf_pull_data(struct osnoise_tool *tool)
value_irq, value_thread, value_user);
if (err)
return err;
- for (i = 0; i < data->nr_cpus; i++) {
+ for (i = 0; i < nr_cpus; i++) {
data->hist[i].irq[data->entries] = value_irq[i];
data->hist[i].thread[data->entries] = value_thread[i];
data->hist[i].user[data->entries] = value_user[i];
@@ -300,7 +298,7 @@ static void timerlat_hist_header(struct osnoise_tool *tool)
if (!params->common.hist.no_index)
trace_seq_printf(s, "Index");
- for_each_monitored_cpu(cpu, data->nr_cpus, ¶ms->common) {
+ for_each_monitored_cpu(cpu, nr_cpus, ¶ms->common) {
if (!data->hist[cpu].irq_count && !data->hist[cpu].thread_count)
continue;
@@ -352,7 +350,7 @@ timerlat_print_summary(struct timerlat_params *params,
if (!params->common.hist.no_index)
trace_seq_printf(trace->seq, "count:");
- for_each_monitored_cpu(cpu, data->nr_cpus, ¶ms->common) {
+ for_each_monitored_cpu(cpu, nr_cpus, ¶ms->common) {
if (!data->hist[cpu].irq_count && !data->hist[cpu].thread_count)
continue;
@@ -374,7 +372,7 @@ timerlat_print_summary(struct timerlat_params *params,
if (!params->common.hist.no_index)
trace_seq_printf(trace->seq, "min: ");
- for_each_monitored_cpu(cpu, data->nr_cpus, ¶ms->common) {
+ for_each_monitored_cpu(cpu, nr_cpus, ¶ms->common) {
if (!data->hist[cpu].irq_count && !data->hist[cpu].thread_count)
continue;
@@ -402,7 +400,7 @@ timerlat_print_summary(struct timerlat_params *params,
if (!params->common.hist.no_index)
trace_seq_printf(trace->seq, "avg: ");
- for_each_monitored_cpu(cpu, data->nr_cpus, ¶ms->common) {
+ for_each_monitored_cpu(cpu, nr_cpus, ¶ms->common) {
if (!data->hist[cpu].irq_count && !data->hist[cpu].thread_count)
continue;
@@ -430,7 +428,7 @@ timerlat_print_summary(struct timerlat_params *params,
if (!params->common.hist.no_index)
trace_seq_printf(trace->seq, "max: ");
- for_each_monitored_cpu(cpu, data->nr_cpus, ¶ms->common) {
+ for_each_monitored_cpu(cpu, nr_cpus, ¶ms->common) {
if (!data->hist[cpu].irq_count && !data->hist[cpu].thread_count)
continue;
@@ -475,7 +473,7 @@ timerlat_print_stats_all(struct timerlat_params *params,
sum.min_thread = ~0;
sum.min_user = ~0;
- for_each_monitored_cpu(cpu, data->nr_cpus, ¶ms->common) {
+ for_each_monitored_cpu(cpu, nr_cpus, ¶ms->common) {
if (!data->hist[cpu].irq_count && !data->hist[cpu].thread_count)
continue;
@@ -622,7 +620,7 @@ timerlat_print_stats(struct osnoise_tool *tool)
trace_seq_printf(trace->seq, "%-6d",
bucket * data->bucket_size);
- for_each_monitored_cpu(cpu, data->nr_cpus, ¶ms->common) {
+ for_each_monitored_cpu(cpu, nr_cpus, ¶ms->common) {
if (!data->hist[cpu].irq_count && !data->hist[cpu].thread_count)
continue;
@@ -660,7 +658,7 @@ timerlat_print_stats(struct osnoise_tool *tool)
if (!params->common.hist.no_index)
trace_seq_printf(trace->seq, "over: ");
- for_each_monitored_cpu(cpu, data->nr_cpus, ¶ms->common) {
+ for_each_monitored_cpu(cpu, nr_cpus, ¶ms->common) {
if (!data->hist[cpu].irq_count && !data->hist[cpu].thread_count)
continue;
diff --git a/tools/tracing/rtla/src/timerlat_top.c b/tools/tracing/rtla/src/timerlat_top.c
index 994e89a57cd3..8fad4edb0d72 100644
--- a/tools/tracing/rtla/src/timerlat_top.c
+++ b/tools/tracing/rtla/src/timerlat_top.c
@@ -41,7 +41,6 @@ struct timerlat_top_cpu {
struct timerlat_top_data {
struct timerlat_top_cpu *cpu_data;
- int nr_cpus;
};
/*
@@ -71,8 +70,6 @@ static struct timerlat_top_data *timerlat_alloc_top(void)
if (!data)
return NULL;
- data->nr_cpus = nr_cpus;
-
/* one set of histograms per CPU */
data->cpu_data = calloc(1, sizeof(*data->cpu_data) * nr_cpus);
if (!data->cpu_data)
@@ -190,16 +187,16 @@ static int timerlat_top_bpf_pull_data(struct osnoise_tool *tool)
{
struct timerlat_top_data *data = tool->data;
int i, err;
- long long value_irq[data->nr_cpus],
- value_thread[data->nr_cpus],
- value_user[data->nr_cpus];
+ long long value_irq[nr_cpus],
+ value_thread[nr_cpus],
+ value_user[nr_cpus];
/* Pull summary */
err = timerlat_bpf_get_summary_value(SUMMARY_CURRENT,
value_irq, value_thread, value_user);
if (err)
return err;
- for (i = 0; i < data->nr_cpus; i++) {
+ for (i = 0; i < nr_cpus; i++) {
data->cpu_data[i].cur_irq = value_irq[i];
data->cpu_data[i].cur_thread = value_thread[i];
data->cpu_data[i].cur_user = value_user[i];
@@ -209,7 +206,7 @@ static int timerlat_top_bpf_pull_data(struct osnoise_tool *tool)
value_irq, value_thread, value_user);
if (err)
return err;
- for (i = 0; i < data->nr_cpus; i++) {
+ for (i = 0; i < nr_cpus; i++) {
data->cpu_data[i].irq_count = value_irq[i];
data->cpu_data[i].thread_count = value_thread[i];
data->cpu_data[i].user_count = value_user[i];
@@ -219,7 +216,7 @@ static int timerlat_top_bpf_pull_data(struct osnoise_tool *tool)
value_irq, value_thread, value_user);
if (err)
return err;
- for (i = 0; i < data->nr_cpus; i++) {
+ for (i = 0; i < nr_cpus; i++) {
data->cpu_data[i].min_irq = value_irq[i];
data->cpu_data[i].min_thread = value_thread[i];
data->cpu_data[i].min_user = value_user[i];
@@ -229,7 +226,7 @@ static int timerlat_top_bpf_pull_data(struct osnoise_tool *tool)
value_irq, value_thread, value_user);
if (err)
return err;
- for (i = 0; i < data->nr_cpus; i++) {
+ for (i = 0; i < nr_cpus; i++) {
data->cpu_data[i].max_irq = value_irq[i];
data->cpu_data[i].max_thread = value_thread[i];
data->cpu_data[i].max_user = value_user[i];
@@ -239,7 +236,7 @@ static int timerlat_top_bpf_pull_data(struct osnoise_tool *tool)
value_irq, value_thread, value_user);
if (err)
return err;
- for (i = 0; i < data->nr_cpus; i++) {
+ for (i = 0; i < nr_cpus; i++) {
data->cpu_data[i].sum_irq = value_irq[i];
data->cpu_data[i].sum_thread = value_thread[i];
data->cpu_data[i].sum_user = value_user[i];
--
2.53.0
^ permalink raw reply related
* [PATCH v4 2/4] tools/rtla: Remove unneeded nr_cpus arguments
From: Costa Shulyupin @ 2026-03-06 19:49 UTC (permalink / raw)
To: Steven Rostedt, Tomas Glozar, Costa Shulyupin, Crystal Wood,
Wander Lairson Costa, John Kacur, Ivan Pravdin, Tiezhu Yang,
linux-trace-kernel, linux-kernel, bpf
In-Reply-To: <20260306194953.2511960-1-costa.shul@redhat.com>
nr_cpus does not change at runtime, so passing it through function
arguments is unnecessary.
Use the global nr_cpus instead of propagating it via parameters.
Signed-off-by: Costa Shulyupin <costa.shul@redhat.com>
---
tools/tracing/rtla/src/osnoise_hist.c | 4 ++--
tools/tracing/rtla/src/osnoise_top.c | 4 ++--
tools/tracing/rtla/src/timerlat_bpf.c | 19 ++++++++-----------
tools/tracing/rtla/src/timerlat_bpf.h | 12 ++++--------
tools/tracing/rtla/src/timerlat_hist.c | 21 ++++++++-------------
tools/tracing/rtla/src/timerlat_top.c | 19 +++++++------------
tools/tracing/rtla/src/timerlat_u.c | 6 +++---
7 files changed, 34 insertions(+), 51 deletions(-)
diff --git a/tools/tracing/rtla/src/osnoise_hist.c b/tools/tracing/rtla/src/osnoise_hist.c
index 00b8c95cbf85..f39f60d3b00e 100644
--- a/tools/tracing/rtla/src/osnoise_hist.c
+++ b/tools/tracing/rtla/src/osnoise_hist.c
@@ -62,7 +62,7 @@ static void osnoise_free_hist_tool(struct osnoise_tool *tool)
* osnoise_alloc_histogram - alloc runtime data
*/
static struct osnoise_hist_data
-*osnoise_alloc_histogram(int nr_cpus, int entries, int bucket_size)
+*osnoise_alloc_histogram(int entries, int bucket_size)
{
struct osnoise_hist_data *data;
int cpu;
@@ -651,7 +651,7 @@ static struct osnoise_tool
if (!tool)
return NULL;
- tool->data = osnoise_alloc_histogram(nr_cpus, params->hist.entries,
+ tool->data = osnoise_alloc_histogram(params->hist.entries,
params->hist.bucket_size);
if (!tool->data)
goto out_err;
diff --git a/tools/tracing/rtla/src/osnoise_top.c b/tools/tracing/rtla/src/osnoise_top.c
index 9a6cd9a2470a..3a241b69f622 100644
--- a/tools/tracing/rtla/src/osnoise_top.c
+++ b/tools/tracing/rtla/src/osnoise_top.c
@@ -51,7 +51,7 @@ static void osnoise_free_top_tool(struct osnoise_tool *tool)
/*
* osnoise_alloc_histogram - alloc runtime data
*/
-static struct osnoise_top_data *osnoise_alloc_top(int nr_cpus)
+static struct osnoise_top_data *osnoise_alloc_top(void)
{
struct osnoise_top_data *data;
@@ -495,7 +495,7 @@ struct osnoise_tool *osnoise_init_top(struct common_params *params)
if (!tool)
return NULL;
- tool->data = osnoise_alloc_top(nr_cpus);
+ tool->data = osnoise_alloc_top();
if (!tool->data) {
osnoise_destroy_tool(tool);
return NULL;
diff --git a/tools/tracing/rtla/src/timerlat_bpf.c b/tools/tracing/rtla/src/timerlat_bpf.c
index 05adf18303df..dd3cf71d74e5 100644
--- a/tools/tracing/rtla/src/timerlat_bpf.c
+++ b/tools/tracing/rtla/src/timerlat_bpf.c
@@ -147,24 +147,23 @@ static int get_value(struct bpf_map *map_irq,
int key,
long long *value_irq,
long long *value_thread,
- long long *value_user,
- int cpus)
+ long long *value_user)
{
int err;
err = bpf_map__lookup_elem(map_irq, &key,
sizeof(unsigned int), value_irq,
- sizeof(long long) * cpus, 0);
+ sizeof(long long) * nr_cpus, 0);
if (err)
return err;
err = bpf_map__lookup_elem(map_thread, &key,
sizeof(unsigned int), value_thread,
- sizeof(long long) * cpus, 0);
+ sizeof(long long) * nr_cpus, 0);
if (err)
return err;
err = bpf_map__lookup_elem(map_user, &key,
sizeof(unsigned int), value_user,
- sizeof(long long) * cpus, 0);
+ sizeof(long long) * nr_cpus, 0);
if (err)
return err;
return 0;
@@ -176,13 +175,12 @@ static int get_value(struct bpf_map *map_irq,
int timerlat_bpf_get_hist_value(int key,
long long *value_irq,
long long *value_thread,
- long long *value_user,
- int cpus)
+ long long *value_user)
{
return get_value(bpf->maps.hist_irq,
bpf->maps.hist_thread,
bpf->maps.hist_user,
- key, value_irq, value_thread, value_user, cpus);
+ key, value_irq, value_thread, value_user);
}
/*
@@ -191,13 +189,12 @@ int timerlat_bpf_get_hist_value(int key,
int timerlat_bpf_get_summary_value(enum summary_field key,
long long *value_irq,
long long *value_thread,
- long long *value_user,
- int cpus)
+ long long *value_user)
{
return get_value(bpf->maps.summary_irq,
bpf->maps.summary_thread,
bpf->maps.summary_user,
- key, value_irq, value_thread, value_user, cpus);
+ key, value_irq, value_thread, value_user);
}
/*
diff --git a/tools/tracing/rtla/src/timerlat_bpf.h b/tools/tracing/rtla/src/timerlat_bpf.h
index 169abeaf4363..531c9ef16f51 100644
--- a/tools/tracing/rtla/src/timerlat_bpf.h
+++ b/tools/tracing/rtla/src/timerlat_bpf.h
@@ -23,13 +23,11 @@ int timerlat_bpf_restart_tracing(void);
int timerlat_bpf_get_hist_value(int key,
long long *value_irq,
long long *value_thread,
- long long *value_user,
- int cpus);
+ long long *value_user);
int timerlat_bpf_get_summary_value(enum summary_field key,
long long *value_irq,
long long *value_thread,
- long long *value_user,
- int cpus);
+ long long *value_user);
int timerlat_load_bpf_action_program(const char *program_path);
static inline int have_libbpf_support(void) { return 1; }
#else
@@ -45,16 +43,14 @@ static inline int timerlat_bpf_restart_tracing(void) { return -1; };
static inline int timerlat_bpf_get_hist_value(int key,
long long *value_irq,
long long *value_thread,
- long long *value_user,
- int cpus)
+ long long *value_user)
{
return -1;
}
static inline int timerlat_bpf_get_summary_value(enum summary_field key,
long long *value_irq,
long long *value_thread,
- long long *value_user,
- int cpus)
+ long long *value_user)
{
return -1;
}
diff --git a/tools/tracing/rtla/src/timerlat_hist.c b/tools/tracing/rtla/src/timerlat_hist.c
index 3ebe41eed9f6..7e735b62488c 100644
--- a/tools/tracing/rtla/src/timerlat_hist.c
+++ b/tools/tracing/rtla/src/timerlat_hist.c
@@ -83,7 +83,7 @@ static void timerlat_free_histogram_tool(struct osnoise_tool *tool)
* timerlat_alloc_histogram - alloc runtime data
*/
static struct timerlat_hist_data
-*timerlat_alloc_histogram(int nr_cpus, int entries, int bucket_size)
+*timerlat_alloc_histogram(int entries, int bucket_size)
{
struct timerlat_hist_data *data;
int cpu;
@@ -211,7 +211,7 @@ static int timerlat_hist_bpf_pull_data(struct osnoise_tool *tool)
/* Pull histogram */
for (i = 0; i < data->entries; i++) {
err = timerlat_bpf_get_hist_value(i, value_irq, value_thread,
- value_user, data->nr_cpus);
+ value_user);
if (err)
return err;
for (j = 0; j < data->nr_cpus; j++) {
@@ -223,8 +223,7 @@ static int timerlat_hist_bpf_pull_data(struct osnoise_tool *tool)
/* Pull summary */
err = timerlat_bpf_get_summary_value(SUMMARY_COUNT,
- value_irq, value_thread, value_user,
- data->nr_cpus);
+ value_irq, value_thread, value_user);
if (err)
return err;
for (i = 0; i < data->nr_cpus; i++) {
@@ -234,8 +233,7 @@ static int timerlat_hist_bpf_pull_data(struct osnoise_tool *tool)
}
err = timerlat_bpf_get_summary_value(SUMMARY_MIN,
- value_irq, value_thread, value_user,
- data->nr_cpus);
+ value_irq, value_thread, value_user);
if (err)
return err;
for (i = 0; i < data->nr_cpus; i++) {
@@ -245,8 +243,7 @@ static int timerlat_hist_bpf_pull_data(struct osnoise_tool *tool)
}
err = timerlat_bpf_get_summary_value(SUMMARY_MAX,
- value_irq, value_thread, value_user,
- data->nr_cpus);
+ value_irq, value_thread, value_user);
if (err)
return err;
for (i = 0; i < data->nr_cpus; i++) {
@@ -256,8 +253,7 @@ static int timerlat_hist_bpf_pull_data(struct osnoise_tool *tool)
}
err = timerlat_bpf_get_summary_value(SUMMARY_SUM,
- value_irq, value_thread, value_user,
- data->nr_cpus);
+ value_irq, value_thread, value_user);
if (err)
return err;
for (i = 0; i < data->nr_cpus; i++) {
@@ -267,8 +263,7 @@ static int timerlat_hist_bpf_pull_data(struct osnoise_tool *tool)
}
err = timerlat_bpf_get_summary_value(SUMMARY_OVERFLOW,
- value_irq, value_thread, value_user,
- data->nr_cpus);
+ value_irq, value_thread, value_user);
if (err)
return err;
for (i = 0; i < data->nr_cpus; i++) {
@@ -1045,7 +1040,7 @@ static struct osnoise_tool
if (!tool)
return NULL;
- tool->data = timerlat_alloc_histogram(nr_cpus, params->hist.entries,
+ tool->data = timerlat_alloc_histogram(params->hist.entries,
params->hist.bucket_size);
if (!tool->data)
goto out_err;
diff --git a/tools/tracing/rtla/src/timerlat_top.c b/tools/tracing/rtla/src/timerlat_top.c
index 4105638f45c4..994e89a57cd3 100644
--- a/tools/tracing/rtla/src/timerlat_top.c
+++ b/tools/tracing/rtla/src/timerlat_top.c
@@ -62,7 +62,7 @@ static void timerlat_free_top_tool(struct osnoise_tool *tool)
/*
* timerlat_alloc_histogram - alloc runtime data
*/
-static struct timerlat_top_data *timerlat_alloc_top(int nr_cpus)
+static struct timerlat_top_data *timerlat_alloc_top(void)
{
struct timerlat_top_data *data;
int cpu;
@@ -196,8 +196,7 @@ static int timerlat_top_bpf_pull_data(struct osnoise_tool *tool)
/* Pull summary */
err = timerlat_bpf_get_summary_value(SUMMARY_CURRENT,
- value_irq, value_thread, value_user,
- data->nr_cpus);
+ value_irq, value_thread, value_user);
if (err)
return err;
for (i = 0; i < data->nr_cpus; i++) {
@@ -207,8 +206,7 @@ static int timerlat_top_bpf_pull_data(struct osnoise_tool *tool)
}
err = timerlat_bpf_get_summary_value(SUMMARY_COUNT,
- value_irq, value_thread, value_user,
- data->nr_cpus);
+ value_irq, value_thread, value_user);
if (err)
return err;
for (i = 0; i < data->nr_cpus; i++) {
@@ -218,8 +216,7 @@ static int timerlat_top_bpf_pull_data(struct osnoise_tool *tool)
}
err = timerlat_bpf_get_summary_value(SUMMARY_MIN,
- value_irq, value_thread, value_user,
- data->nr_cpus);
+ value_irq, value_thread, value_user);
if (err)
return err;
for (i = 0; i < data->nr_cpus; i++) {
@@ -229,8 +226,7 @@ static int timerlat_top_bpf_pull_data(struct osnoise_tool *tool)
}
err = timerlat_bpf_get_summary_value(SUMMARY_MAX,
- value_irq, value_thread, value_user,
- data->nr_cpus);
+ value_irq, value_thread, value_user);
if (err)
return err;
for (i = 0; i < data->nr_cpus; i++) {
@@ -240,8 +236,7 @@ static int timerlat_top_bpf_pull_data(struct osnoise_tool *tool)
}
err = timerlat_bpf_get_summary_value(SUMMARY_SUM,
- value_irq, value_thread, value_user,
- data->nr_cpus);
+ value_irq, value_thread, value_user);
if (err)
return err;
for (i = 0; i < data->nr_cpus; i++) {
@@ -791,7 +786,7 @@ static struct osnoise_tool
if (!top)
return NULL;
- top->data = timerlat_alloc_top(nr_cpus);
+ top->data = timerlat_alloc_top();
if (!top->data)
goto out_err;
diff --git a/tools/tracing/rtla/src/timerlat_u.c b/tools/tracing/rtla/src/timerlat_u.c
index a569fe7f93aa..03b4e68e8b1e 100644
--- a/tools/tracing/rtla/src/timerlat_u.c
+++ b/tools/tracing/rtla/src/timerlat_u.c
@@ -99,7 +99,7 @@ static int timerlat_u_main(int cpu, struct timerlat_u_params *params)
*
* Return the number of processes that received the kill.
*/
-static int timerlat_u_send_kill(pid_t *procs, int nr_cpus)
+static int timerlat_u_send_kill(pid_t *procs)
{
int killed = 0;
int i, retval;
@@ -169,7 +169,7 @@ void *timerlat_u_dispatcher(void *data)
/* parent */
if (pid == -1) {
- timerlat_u_send_kill(procs, nr_cpus);
+ timerlat_u_send_kill(procs);
debug_msg("Failed to create child processes");
pthread_exit(&retval);
}
@@ -196,7 +196,7 @@ void *timerlat_u_dispatcher(void *data)
sleep(1);
}
- timerlat_u_send_kill(procs, nr_cpus);
+ timerlat_u_send_kill(procs);
while (procs_count) {
pid = waitpid(-1, &wstatus, 0);
--
2.53.0
^ permalink raw reply related
* [PATCH v4 1/4] tools/rtla: Consolidate nr_cpus usage across all tools
From: Costa Shulyupin @ 2026-03-06 19:49 UTC (permalink / raw)
To: Steven Rostedt, Tomas Glozar, Costa Shulyupin, Crystal Wood,
Wander Lairson Costa, John Kacur, Ivan Pravdin, Tiezhu Yang,
linux-trace-kernel, linux-kernel, bpf
In-Reply-To: <20260306194953.2511960-1-costa.shul@redhat.com>
sysconf(_SC_NPROCESSORS_CONF) (via get_nprocs_conf) reflects
cpu_possible_mask, which is fixed at boot time, so querying it
repeatedly is unnecessary.
Replace multiple calls to sysconf(_SC_NPROCESSORS_CONF) with a single
global nr_cpus variable initialized once at startup.
`#pragma once` in timerlat_u.h is needed for pre-C23 compilers to avoid
redefinition errors.
Signed-off-by: Costa Shulyupin <costa.shul@redhat.com>
---
tools/tracing/rtla/src/common.c | 7 +++-
tools/tracing/rtla/src/common.h | 2 +
tools/tracing/rtla/src/osnoise_hist.c | 3 --
tools/tracing/rtla/src/osnoise_top.c | 7 ----
tools/tracing/rtla/src/timerlat.c | 5 +--
tools/tracing/rtla/src/timerlat_aa.c | 1 -
tools/tracing/rtla/src/timerlat_hist.c | 3 --
tools/tracing/rtla/src/timerlat_top.c | 7 ----
tools/tracing/rtla/src/timerlat_u.c | 3 +-
tools/tracing/rtla/src/timerlat_u.h | 1 +
tools/tracing/rtla/src/utils.c | 10 +----
tools/tracing/rtla/tests/unit/unit_tests.c | 44 ++++++++++------------
12 files changed, 31 insertions(+), 62 deletions(-)
diff --git a/tools/tracing/rtla/src/common.c b/tools/tracing/rtla/src/common.c
index f310b0d59ad3..a31fbaea5da6 100644
--- a/tools/tracing/rtla/src/common.c
+++ b/tools/tracing/rtla/src/common.c
@@ -5,12 +5,14 @@
#include <signal.h>
#include <stdlib.h>
#include <string.h>
-#include <unistd.h>
#include <getopt.h>
+#include <sys/sysinfo.h>
+
#include "common.h"
struct trace_instance *trace_inst;
volatile int stop_tracing;
+int nr_cpus;
static void stop_trace(int sig)
{
@@ -165,7 +167,7 @@ common_apply_config(struct osnoise_tool *tool, struct common_params *params)
}
if (!params->cpus) {
- for (i = 0; i < sysconf(_SC_NPROCESSORS_CONF); i++)
+ for (i = 0; i < nr_cpus; i++)
CPU_SET(i, ¶ms->monitored_cpus);
}
@@ -213,6 +215,7 @@ int run_tool(struct tool_ops *ops, int argc, char *argv[])
bool stopped;
int retval;
+ nr_cpus = get_nprocs_conf();
params = ops->parse_args(argc, argv);
if (!params)
exit(1);
diff --git a/tools/tracing/rtla/src/common.h b/tools/tracing/rtla/src/common.h
index d4b3715700be..90a3c0d1dbf3 100644
--- a/tools/tracing/rtla/src/common.h
+++ b/tools/tracing/rtla/src/common.h
@@ -108,6 +108,8 @@ struct common_params {
struct timerlat_u_params user;
};
+extern int nr_cpus;
+
#define for_each_monitored_cpu(cpu, nr_cpus, common) \
for (cpu = 0; cpu < nr_cpus; cpu++) \
if (!(common)->cpus || CPU_ISSET(cpu, &(common)->monitored_cpus))
diff --git a/tools/tracing/rtla/src/osnoise_hist.c b/tools/tracing/rtla/src/osnoise_hist.c
index 5c863e7aad28..00b8c95cbf85 100644
--- a/tools/tracing/rtla/src/osnoise_hist.c
+++ b/tools/tracing/rtla/src/osnoise_hist.c
@@ -646,9 +646,6 @@ static struct osnoise_tool
*osnoise_init_hist(struct common_params *params)
{
struct osnoise_tool *tool;
- int nr_cpus;
-
- nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
tool = osnoise_init_tool("osnoise_hist");
if (!tool)
diff --git a/tools/tracing/rtla/src/osnoise_top.c b/tools/tracing/rtla/src/osnoise_top.c
index b7aed40fd216..9a6cd9a2470a 100644
--- a/tools/tracing/rtla/src/osnoise_top.c
+++ b/tools/tracing/rtla/src/osnoise_top.c
@@ -232,12 +232,8 @@ osnoise_print_stats(struct osnoise_tool *top)
{
struct osnoise_params *params = to_osnoise_params(top->params);
struct trace_instance *trace = &top->trace;
- static int nr_cpus = -1;
int i;
- if (nr_cpus == -1)
- nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
-
if (!params->common.quiet)
clear_terminal(trace->seq);
@@ -494,9 +490,6 @@ osnoise_top_apply_config(struct osnoise_tool *tool)
struct osnoise_tool *osnoise_init_top(struct common_params *params)
{
struct osnoise_tool *tool;
- int nr_cpus;
-
- nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
tool = osnoise_init_tool("osnoise_top");
if (!tool)
diff --git a/tools/tracing/rtla/src/timerlat.c b/tools/tracing/rtla/src/timerlat.c
index 9e4daed0aafc..31c921efa7c1 100644
--- a/tools/tracing/rtla/src/timerlat.c
+++ b/tools/tracing/rtla/src/timerlat.c
@@ -99,7 +99,7 @@ timerlat_apply_config(struct osnoise_tool *tool, struct timerlat_params *params)
int timerlat_enable(struct osnoise_tool *tool)
{
struct timerlat_params *params = to_timerlat_params(tool->params);
- int retval, nr_cpus, i;
+ int retval, i;
if (params->dma_latency >= 0) {
dma_latency_fd = set_cpu_dma_latency(params->dma_latency);
@@ -115,8 +115,6 @@ int timerlat_enable(struct osnoise_tool *tool)
return -1;
}
- nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
-
for_each_monitored_cpu(i, nr_cpus, ¶ms->common) {
if (save_cpu_idle_disable_state(i) < 0) {
err_msg("Could not save cpu idle state.\n");
@@ -214,7 +212,6 @@ void timerlat_analyze(struct osnoise_tool *tool, bool stopped)
void timerlat_free(struct osnoise_tool *tool)
{
struct timerlat_params *params = to_timerlat_params(tool->params);
- int nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
int i;
timerlat_aa_destroy();
diff --git a/tools/tracing/rtla/src/timerlat_aa.c b/tools/tracing/rtla/src/timerlat_aa.c
index 178de60dcef9..095483375823 100644
--- a/tools/tracing/rtla/src/timerlat_aa.c
+++ b/tools/tracing/rtla/src/timerlat_aa.c
@@ -1043,7 +1043,6 @@ void timerlat_aa_destroy(void)
*/
int timerlat_aa_init(struct osnoise_tool *tool, int dump_tasks, enum stack_format stack_format)
{
- int nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
struct timerlat_aa_context *taa_ctx;
int retval;
diff --git a/tools/tracing/rtla/src/timerlat_hist.c b/tools/tracing/rtla/src/timerlat_hist.c
index 88211e54bc9d..3ebe41eed9f6 100644
--- a/tools/tracing/rtla/src/timerlat_hist.c
+++ b/tools/tracing/rtla/src/timerlat_hist.c
@@ -1040,9 +1040,6 @@ static struct osnoise_tool
*timerlat_init_hist(struct common_params *params)
{
struct osnoise_tool *tool;
- int nr_cpus;
-
- nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
tool = osnoise_init_tool("timerlat_hist");
if (!tool)
diff --git a/tools/tracing/rtla/src/timerlat_top.c b/tools/tracing/rtla/src/timerlat_top.c
index 7a00f3844f56..4105638f45c4 100644
--- a/tools/tracing/rtla/src/timerlat_top.c
+++ b/tools/tracing/rtla/src/timerlat_top.c
@@ -442,15 +442,11 @@ timerlat_print_stats(struct osnoise_tool *top)
struct timerlat_params *params = to_timerlat_params(top->params);
struct trace_instance *trace = &top->trace;
struct timerlat_top_cpu summary;
- static int nr_cpus = -1;
int i;
if (params->common.aa_only)
return;
- if (nr_cpus == -1)
- nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
-
if (!params->common.quiet)
clear_terminal(trace->seq);
@@ -790,9 +786,6 @@ static struct osnoise_tool
*timerlat_init_top(struct common_params *params)
{
struct osnoise_tool *top;
- int nr_cpus;
-
- nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
top = osnoise_init_tool("timerlat_top");
if (!top)
diff --git a/tools/tracing/rtla/src/timerlat_u.c b/tools/tracing/rtla/src/timerlat_u.c
index ce68e39d25fd..a569fe7f93aa 100644
--- a/tools/tracing/rtla/src/timerlat_u.c
+++ b/tools/tracing/rtla/src/timerlat_u.c
@@ -16,7 +16,7 @@
#include <sys/wait.h>
#include <sys/prctl.h>
-#include "utils.h"
+#include "common.h"
#include "timerlat_u.h"
/*
@@ -131,7 +131,6 @@ static int timerlat_u_send_kill(pid_t *procs, int nr_cpus)
*/
void *timerlat_u_dispatcher(void *data)
{
- int nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
struct timerlat_u_params *params = data;
char proc_name[128];
int procs_count = 0;
diff --git a/tools/tracing/rtla/src/timerlat_u.h b/tools/tracing/rtla/src/timerlat_u.h
index 661511908957..a692331bd1c7 100644
--- a/tools/tracing/rtla/src/timerlat_u.h
+++ b/tools/tracing/rtla/src/timerlat_u.h
@@ -1,4 +1,5 @@
// SPDX-License-Identifier: GPL-2.0
+#pragma once
/*
* Copyright (C) 2023 Red Hat Inc, Daniel Bristot de Oliveira <bristot@kernel.org>
*/
diff --git a/tools/tracing/rtla/src/utils.c b/tools/tracing/rtla/src/utils.c
index d979159f6b70..77593718766a 100644
--- a/tools/tracing/rtla/src/utils.c
+++ b/tools/tracing/rtla/src/utils.c
@@ -19,7 +19,7 @@
#include <stdio.h>
#include <limits.h>
-#include "utils.h"
+#include "common.h"
#define MAX_MSG_LENGTH 1024
int config_debug;
@@ -119,14 +119,11 @@ int parse_cpu_set(char *cpu_list, cpu_set_t *set)
{
const char *p;
int end_cpu;
- int nr_cpus;
int cpu;
int i;
CPU_ZERO(set);
- nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
-
for (p = cpu_list; *p; ) {
cpu = atoi(p);
if (cpu < 0 || (!cpu && *p != '0') || cpu >= nr_cpus)
@@ -577,7 +574,6 @@ int save_cpu_idle_disable_state(unsigned int cpu)
unsigned int nr_states;
unsigned int state;
int disabled;
- int nr_cpus;
nr_states = cpuidle_state_count(cpu);
@@ -585,7 +581,6 @@ int save_cpu_idle_disable_state(unsigned int cpu)
return 0;
if (saved_cpu_idle_disable_state == NULL) {
- nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
saved_cpu_idle_disable_state = calloc(nr_cpus, sizeof(unsigned int *));
if (!saved_cpu_idle_disable_state)
return -1;
@@ -662,13 +657,10 @@ int restore_cpu_idle_disable_state(unsigned int cpu)
void free_cpu_idle_disable_states(void)
{
int cpu;
- int nr_cpus;
if (!saved_cpu_idle_disable_state)
return;
- nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
-
for (cpu = 0; cpu < nr_cpus; cpu++) {
free(saved_cpu_idle_disable_state[cpu]);
saved_cpu_idle_disable_state[cpu] = NULL;
diff --git a/tools/tracing/rtla/tests/unit/unit_tests.c b/tools/tracing/rtla/tests/unit/unit_tests.c
index aa53f8605e36..f3c6d89e3300 100644
--- a/tools/tracing/rtla/tests/unit/unit_tests.c
+++ b/tools/tracing/rtla/tests/unit/unit_tests.c
@@ -7,8 +7,10 @@
#include <sched.h>
#include <limits.h>
#include <unistd.h>
+#include <sys/sysinfo.h>
#include "../../src/utils.h"
+int nr_cpus;
START_TEST(test_strtoi)
{
@@ -34,35 +36,29 @@ END_TEST
START_TEST(test_parse_cpu_set)
{
cpu_set_t set;
- int nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
+ nr_cpus = 8;
ck_assert_int_eq(parse_cpu_set("0", &set), 0);
ck_assert(CPU_ISSET(0, &set));
ck_assert(!CPU_ISSET(1, &set));
- if (nr_cpus > 2) {
- ck_assert_int_eq(parse_cpu_set("0,2", &set), 0);
- ck_assert(CPU_ISSET(0, &set));
- ck_assert(CPU_ISSET(2, &set));
- }
-
- if (nr_cpus > 3) {
- ck_assert_int_eq(parse_cpu_set("0-3", &set), 0);
- ck_assert(CPU_ISSET(0, &set));
- ck_assert(CPU_ISSET(1, &set));
- ck_assert(CPU_ISSET(2, &set));
- ck_assert(CPU_ISSET(3, &set));
- }
-
- if (nr_cpus > 5) {
- ck_assert_int_eq(parse_cpu_set("1-3,5", &set), 0);
- ck_assert(!CPU_ISSET(0, &set));
- ck_assert(CPU_ISSET(1, &set));
- ck_assert(CPU_ISSET(2, &set));
- ck_assert(CPU_ISSET(3, &set));
- ck_assert(!CPU_ISSET(4, &set));
- ck_assert(CPU_ISSET(5, &set));
- }
+ ck_assert_int_eq(parse_cpu_set("0,2", &set), 0);
+ ck_assert(CPU_ISSET(0, &set));
+ ck_assert(CPU_ISSET(2, &set));
+
+ ck_assert_int_eq(parse_cpu_set("0-3", &set), 0);
+ ck_assert(CPU_ISSET(0, &set));
+ ck_assert(CPU_ISSET(1, &set));
+ ck_assert(CPU_ISSET(2, &set));
+ ck_assert(CPU_ISSET(3, &set));
+
+ ck_assert_int_eq(parse_cpu_set("1-3,5", &set), 0);
+ ck_assert(!CPU_ISSET(0, &set));
+ ck_assert(CPU_ISSET(1, &set));
+ ck_assert(CPU_ISSET(2, &set));
+ ck_assert(CPU_ISSET(3, &set));
+ ck_assert(!CPU_ISSET(4, &set));
+ ck_assert(CPU_ISSET(5, &set));
ck_assert_int_eq(parse_cpu_set("-1", &set), 1);
ck_assert_int_eq(parse_cpu_set("abc", &set), 1);
--
2.53.0
^ permalink raw reply related
* [PATCH v4 0/4] tools/rtla: Consolidate nr_cpus usage
From: Costa Shulyupin @ 2026-03-06 19:49 UTC (permalink / raw)
To: Steven Rostedt, Tomas Glozar, Costa Shulyupin, Crystal Wood,
Wander Lairson Costa, John Kacur, Ivan Pravdin, Tiezhu Yang,
linux-trace-kernel, linux-kernel, bpf
sysconf(_SC_NPROCESSORS_CONF) (via get_nprocs_conf) reflects
cpu_possible_mask, which is fixed at boot time, so querying it
repeatedly is unnecessary.
Replace multiple calls to sysconf(_SC_NPROCESSORS_CONF) with a single
global nr_cpus variable initialized once at startup.
v4:
- Reorder change of BPF functions
- Update unit test
v3:
- Remove unneeded cpus parameter from timerlat BPF functions as
requested by Wander Costa.
v2:
- Add `#pragma once` in timerlat_u.h to avoid redefinition errors with
pre-C23 compilers.
Costa Shulyupin (4):
tools/rtla: Consolidate nr_cpus usage across all tools
tools/rtla: Remove unneeded nr_cpus arguments
tools/rtla: Remove unneeded nr_cpus members
tools/rtla: Remove unneeded nr_cpus from for_each_monitored_cpu
tools/tracing/rtla/src/common.c | 7 ++-
tools/tracing/rtla/src/common.h | 4 +-
tools/tracing/rtla/src/osnoise_hist.c | 26 ++++-----
tools/tracing/rtla/src/osnoise_top.c | 16 ++----
tools/tracing/rtla/src/timerlat.c | 9 ++--
tools/tracing/rtla/src/timerlat_aa.c | 11 ++--
tools/tracing/rtla/src/timerlat_bpf.c | 19 +++----
tools/tracing/rtla/src/timerlat_bpf.h | 12 ++---
tools/tracing/rtla/src/timerlat_hist.c | 62 +++++++++-------------
tools/tracing/rtla/src/timerlat_top.c | 47 ++++++----------
tools/tracing/rtla/src/timerlat_u.c | 9 ++--
tools/tracing/rtla/src/timerlat_u.h | 1 +
tools/tracing/rtla/src/utils.c | 10 +---
tools/tracing/rtla/tests/unit/unit_tests.c | 44 +++++++--------
14 files changed, 108 insertions(+), 169 deletions(-)
--
2.53.0
^ permalink raw reply
* Re: [PATCH] tracing: Move snapshot code out of trace.c and into trace_snapshot.c
From: kernel test robot @ 2026-03-06 19:07 UTC (permalink / raw)
To: Steven Rostedt, LKML, Linux trace kernel
Cc: llvm, oe-kbuild-all, Masami Hiramatsu, Mathieu Desnoyers
In-Reply-To: <20260305211810.3f48aa07@robin>
Hi Steven,
kernel test robot noticed the following build warnings:
[auto build test WARNING on v7.0-rc2]
[cannot apply to trace/for-next linus/master next-20260306]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Steven-Rostedt/tracing-Move-snapshot-code-out-of-trace-c-and-into-trace_snapshot-c/20260306-102714
base: v7.0-rc2
patch link: https://lore.kernel.org/r/20260305211810.3f48aa07%40robin
patch subject: [PATCH] tracing: Move snapshot code out of trace.c and into trace_snapshot.c
config: sparc64-defconfig (https://download.01.org/0day-ci/archive/20260307/202603070230.Zz4BBLtb-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260307/202603070230.Zz4BBLtb-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202603070230.Zz4BBLtb-lkp@intel.com/
All warnings (new ones prefixed by >>):
>> kernel/trace/trace.c:820:5: warning: no previous prototype for function 'tracing_alloc_snapshot' [-Wmissing-prototypes]
820 | int tracing_alloc_snapshot(void)
| ^
kernel/trace/trace.c:820:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
820 | int tracing_alloc_snapshot(void)
| ^
| static
1 warning generated.
vim +/tracing_alloc_snapshot +820 kernel/trace/trace.c
ad909e21bbe69f1 Steven Rostedt (Red Hat 2013-03-06 792)
93e31ffbf417a84 Tom Zanussi 2013-10-24 793 /**
93e31ffbf417a84 Tom Zanussi 2013-10-24 794 * tracing_alloc_snapshot - allocate snapshot buffer.
93e31ffbf417a84 Tom Zanussi 2013-10-24 795 *
93e31ffbf417a84 Tom Zanussi 2013-10-24 796 * This only allocates the snapshot buffer if it isn't already
93e31ffbf417a84 Tom Zanussi 2013-10-24 797 * allocated - it doesn't also take a snapshot.
93e31ffbf417a84 Tom Zanussi 2013-10-24 798 *
93e31ffbf417a84 Tom Zanussi 2013-10-24 799 * This is meant to be used in cases where the snapshot buffer needs
93e31ffbf417a84 Tom Zanussi 2013-10-24 800 * to be set up for events that can't sleep but need to be able to
93e31ffbf417a84 Tom Zanussi 2013-10-24 801 * trigger a snapshot.
93e31ffbf417a84 Tom Zanussi 2013-10-24 802 */
93e31ffbf417a84 Tom Zanussi 2013-10-24 803 int tracing_alloc_snapshot(void)
93e31ffbf417a84 Tom Zanussi 2013-10-24 804 {
93e31ffbf417a84 Tom Zanussi 2013-10-24 805 struct trace_array *tr = &global_trace;
93e31ffbf417a84 Tom Zanussi 2013-10-24 806 int ret;
93e31ffbf417a84 Tom Zanussi 2013-10-24 807
2824f5033248600 Steven Rostedt (VMware 2018-05-28 808) ret = tracing_alloc_snapshot_instance(tr);
93e31ffbf417a84 Tom Zanussi 2013-10-24 809 WARN_ON(ret < 0);
93e31ffbf417a84 Tom Zanussi 2013-10-24 810
93e31ffbf417a84 Tom Zanussi 2013-10-24 811 return ret;
93e31ffbf417a84 Tom Zanussi 2013-10-24 812 }
93e31ffbf417a84 Tom Zanussi 2013-10-24 813 EXPORT_SYMBOL_GPL(tracing_alloc_snapshot);
ad909e21bbe69f1 Steven Rostedt (Red Hat 2013-03-06 814) #else
ad909e21bbe69f1 Steven Rostedt (Red Hat 2013-03-06 815) void tracing_snapshot(void)
ad909e21bbe69f1 Steven Rostedt (Red Hat 2013-03-06 816) {
ad909e21bbe69f1 Steven Rostedt (Red Hat 2013-03-06 817) WARN_ONCE(1, "Snapshot feature not enabled, but internal snapshot used");
ad909e21bbe69f1 Steven Rostedt (Red Hat 2013-03-06 818) }
1b22e382ab40b0e Steven Rostedt (Red Hat 2013-03-09 819) EXPORT_SYMBOL_GPL(tracing_snapshot);
93e31ffbf417a84 Tom Zanussi 2013-10-24 @820 int tracing_alloc_snapshot(void)
93e31ffbf417a84 Tom Zanussi 2013-10-24 821 {
93e31ffbf417a84 Tom Zanussi 2013-10-24 822 WARN_ONCE(1, "Snapshot feature not enabled, but snapshot allocation used");
93e31ffbf417a84 Tom Zanussi 2013-10-24 823 return -ENODEV;
93e31ffbf417a84 Tom Zanussi 2013-10-24 824 }
93e31ffbf417a84 Tom Zanussi 2013-10-24 825 EXPORT_SYMBOL_GPL(tracing_alloc_snapshot);
ad909e21bbe69f1 Steven Rostedt (Red Hat 2013-03-06 826) void tracing_snapshot_alloc(void)
ad909e21bbe69f1 Steven Rostedt (Red Hat 2013-03-06 827) {
ad909e21bbe69f1 Steven Rostedt (Red Hat 2013-03-06 828) /* Give warning */
ad909e21bbe69f1 Steven Rostedt (Red Hat 2013-03-06 829) tracing_snapshot();
ad909e21bbe69f1 Steven Rostedt (Red Hat 2013-03-06 830) }
1b22e382ab40b0e Steven Rostedt (Red Hat 2013-03-09 831) EXPORT_SYMBOL_GPL(tracing_snapshot_alloc);
ad909e21bbe69f1 Steven Rostedt (Red Hat 2013-03-06 832) #endif /* CONFIG_TRACER_SNAPSHOT */
ad909e21bbe69f1 Steven Rostedt (Red Hat 2013-03-06 833)
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
^ permalink raw reply
* Re: [PATCH] tracing: Move snapshot code out of trace.c and into trace_snapshot.c
From: kernel test robot @ 2026-03-06 18:55 UTC (permalink / raw)
To: Steven Rostedt, LKML, Linux trace kernel
Cc: oe-kbuild-all, Masami Hiramatsu, Mathieu Desnoyers
In-Reply-To: <20260305211810.3f48aa07@robin>
Hi Steven,
kernel test robot noticed the following build warnings:
[auto build test WARNING on v7.0-rc2]
[cannot apply to trace/for-next linus/master next-20260305]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Steven-Rostedt/tracing-Move-snapshot-code-out-of-trace-c-and-into-trace_snapshot-c/20260306-102714
base: v7.0-rc2
patch link: https://lore.kernel.org/r/20260305211810.3f48aa07%40robin
patch subject: [PATCH] tracing: Move snapshot code out of trace.c and into trace_snapshot.c
config: sh-defconfig (https://download.01.org/0day-ci/archive/20260307/202603070253.0Z0n4vtm-lkp@intel.com/config)
compiler: sh4-linux-gcc (GCC) 15.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260307/202603070253.0Z0n4vtm-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202603070253.0Z0n4vtm-lkp@intel.com/
All warnings (new ones prefixed by >>):
>> kernel/trace/trace.c:820:5: warning: no previous prototype for 'tracing_alloc_snapshot' [-Wmissing-prototypes]
820 | int tracing_alloc_snapshot(void)
| ^~~~~~~~~~~~~~~~~~~~~~
vim +/tracing_alloc_snapshot +820 kernel/trace/trace.c
ad909e21bbe69f1 Steven Rostedt (Red Hat 2013-03-06 792)
93e31ffbf417a84 Tom Zanussi 2013-10-24 793 /**
93e31ffbf417a84 Tom Zanussi 2013-10-24 794 * tracing_alloc_snapshot - allocate snapshot buffer.
93e31ffbf417a84 Tom Zanussi 2013-10-24 795 *
93e31ffbf417a84 Tom Zanussi 2013-10-24 796 * This only allocates the snapshot buffer if it isn't already
93e31ffbf417a84 Tom Zanussi 2013-10-24 797 * allocated - it doesn't also take a snapshot.
93e31ffbf417a84 Tom Zanussi 2013-10-24 798 *
93e31ffbf417a84 Tom Zanussi 2013-10-24 799 * This is meant to be used in cases where the snapshot buffer needs
93e31ffbf417a84 Tom Zanussi 2013-10-24 800 * to be set up for events that can't sleep but need to be able to
93e31ffbf417a84 Tom Zanussi 2013-10-24 801 * trigger a snapshot.
93e31ffbf417a84 Tom Zanussi 2013-10-24 802 */
93e31ffbf417a84 Tom Zanussi 2013-10-24 803 int tracing_alloc_snapshot(void)
93e31ffbf417a84 Tom Zanussi 2013-10-24 804 {
93e31ffbf417a84 Tom Zanussi 2013-10-24 805 struct trace_array *tr = &global_trace;
93e31ffbf417a84 Tom Zanussi 2013-10-24 806 int ret;
93e31ffbf417a84 Tom Zanussi 2013-10-24 807
2824f5033248600 Steven Rostedt (VMware 2018-05-28 808) ret = tracing_alloc_snapshot_instance(tr);
93e31ffbf417a84 Tom Zanussi 2013-10-24 809 WARN_ON(ret < 0);
93e31ffbf417a84 Tom Zanussi 2013-10-24 810
93e31ffbf417a84 Tom Zanussi 2013-10-24 811 return ret;
93e31ffbf417a84 Tom Zanussi 2013-10-24 812 }
93e31ffbf417a84 Tom Zanussi 2013-10-24 813 EXPORT_SYMBOL_GPL(tracing_alloc_snapshot);
ad909e21bbe69f1 Steven Rostedt (Red Hat 2013-03-06 814) #else
ad909e21bbe69f1 Steven Rostedt (Red Hat 2013-03-06 815) void tracing_snapshot(void)
ad909e21bbe69f1 Steven Rostedt (Red Hat 2013-03-06 816) {
ad909e21bbe69f1 Steven Rostedt (Red Hat 2013-03-06 817) WARN_ONCE(1, "Snapshot feature not enabled, but internal snapshot used");
ad909e21bbe69f1 Steven Rostedt (Red Hat 2013-03-06 818) }
1b22e382ab40b0e Steven Rostedt (Red Hat 2013-03-09 819) EXPORT_SYMBOL_GPL(tracing_snapshot);
93e31ffbf417a84 Tom Zanussi 2013-10-24 @820 int tracing_alloc_snapshot(void)
93e31ffbf417a84 Tom Zanussi 2013-10-24 821 {
93e31ffbf417a84 Tom Zanussi 2013-10-24 822 WARN_ONCE(1, "Snapshot feature not enabled, but snapshot allocation used");
93e31ffbf417a84 Tom Zanussi 2013-10-24 823 return -ENODEV;
93e31ffbf417a84 Tom Zanussi 2013-10-24 824 }
93e31ffbf417a84 Tom Zanussi 2013-10-24 825 EXPORT_SYMBOL_GPL(tracing_alloc_snapshot);
ad909e21bbe69f1 Steven Rostedt (Red Hat 2013-03-06 826) void tracing_snapshot_alloc(void)
ad909e21bbe69f1 Steven Rostedt (Red Hat 2013-03-06 827) {
ad909e21bbe69f1 Steven Rostedt (Red Hat 2013-03-06 828) /* Give warning */
ad909e21bbe69f1 Steven Rostedt (Red Hat 2013-03-06 829) tracing_snapshot();
ad909e21bbe69f1 Steven Rostedt (Red Hat 2013-03-06 830) }
1b22e382ab40b0e Steven Rostedt (Red Hat 2013-03-09 831) EXPORT_SYMBOL_GPL(tracing_snapshot_alloc);
ad909e21bbe69f1 Steven Rostedt (Red Hat 2013-03-06 832) #endif /* CONFIG_TRACER_SNAPSHOT */
ad909e21bbe69f1 Steven Rostedt (Red Hat 2013-03-06 833)
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
^ permalink raw reply
* Re: [PATCH] tracing: Move snapshot code out of trace.c and into trace_snapshot.c
From: kernel test robot @ 2026-03-06 18:55 UTC (permalink / raw)
To: Steven Rostedt, LKML, Linux trace kernel
Cc: oe-kbuild-all, Masami Hiramatsu, Mathieu Desnoyers
In-Reply-To: <20260305211810.3f48aa07@robin>
Hi Steven,
kernel test robot noticed the following build errors:
[auto build test ERROR on v7.0-rc2]
[cannot apply to trace/for-next linus/master next-20260306]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Steven-Rostedt/tracing-Move-snapshot-code-out-of-trace-c-and-into-trace_snapshot-c/20260306-102714
base: v7.0-rc2
patch link: https://lore.kernel.org/r/20260305211810.3f48aa07%40robin
patch subject: [PATCH] tracing: Move snapshot code out of trace.c and into trace_snapshot.c
config: arc-randconfig-002-20260307 (https://download.01.org/0day-ci/archive/20260307/202603070206.u4DPFtuW-lkp@intel.com/config)
compiler: arc-linux-gcc (GCC) 14.3.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260307/202603070206.u4DPFtuW-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202603070206.u4DPFtuW-lkp@intel.com/
All errors (new ones prefixed by >>):
>> kernel/trace/trace_snapshot.c:395:20: error: redefinition of 'latency_fsnotify'
395 | static inline void latency_fsnotify(struct trace_array *tr) { }
| ^~~~~~~~~~~~~~~~
In file included from kernel/trace/trace_snapshot.c:6:
kernel/trace/trace.h:852:20: note: previous definition of 'latency_fsnotify' with type 'void(struct trace_array *)'
852 | static inline void latency_fsnotify(struct trace_array *tr) { }
| ^~~~~~~~~~~~~~~~
vim +/latency_fsnotify +395 kernel/trace/trace_snapshot.c
382
383 void latency_fsnotify(struct trace_array *tr)
384 {
385 if (!fsnotify_wq)
386 return;
387 /*
388 * We cannot call queue_work(&tr->fsnotify_work) from here because it's
389 * possible that we are called from __schedule() or do_idle(), which
390 * could cause a deadlock.
391 */
392 irq_work_queue(&tr->fsnotify_irqwork);
393 }
394 #else
> 395 static inline void latency_fsnotify(struct trace_array *tr) { }
396 #endif /* LATENCY_FS_NOTIFY */
397 static const struct file_operations tracing_max_lat_fops;
398
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
^ permalink raw reply
* Re: [PATCH v13 03/32] ring-buffer: Introduce ring-buffer remotes
From: Markus Elfring @ 2026-03-06 16:37 UTC (permalink / raw)
To: Vincent Donnefort, linux-trace-kernel, kernel-team, kvmarm,
linux-arm-kernel, Joey Gouly, Marc Zyngier, Masami Hiramatsu,
Mathieu Desnoyers, Oliver Upton, Steven Rostedt, Suzuki Poulouse,
Zenghui Yu
Cc: LKML, Aneesh Kumar K.V, John Stultz, Quentin Perret, Will Deacon
In-Reply-To: <20260306143536.339777-4-vdonnefort@google.com>
…
> It is expected from the remote to keep the meta-page updated.
See also once more:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?h=v7.0-rc2#n94
…
> +++ b/kernel/trace/ring_buffer.c
…
> +int ring_buffer_poll_remote(struct trace_buffer *buffer, int cpu)
> +{
…
> + cpus_read_lock();
> +
> + /*
> + * Make sure all the ring buffers are up to date before we start reading
> + * them.
> + */
> + for_each_buffer_cpu(buffer, cpu) {
…
> + }
> +
> + cpus_read_unlock();
> +
> + return 0;
> +}
…
How do you think about to use another lock guard here?
https://elixir.bootlin.com/linux/v7.0-rc1/source/include/linux/cpuhplock.h#L48
Regards,
Markus
^ permalink raw reply
* Re: [PATCH] tracing/osnoise: Add option to align tlat threads
From: Tomas Glozar @ 2026-03-06 15:15 UTC (permalink / raw)
To: Crystal Wood
Cc: Steven Rostedt, Masami Hiramatsu, Mathieu Desnoyers, John Kacur,
Luis Goncalves, Costa Shulyupin, Wander Lairson Costa, LKML,
linux-trace-kernel
In-Reply-To: <238e4851e45a505d7974443c4fe703e61a0fbf55.camel@redhat.com>
út 3. 3. 2026 v 4:21 odesílatel Crystal Wood <crwood@redhat.com> napsal:
> > 1. The wake-up timers are set to absolute time, and are incremented by
> > "period" (once or multiple times, if the timer is significantly
> > delayed) each cycle. What can be done as an alternative to what v1
> > does is this: record the current time when starting the timerlat
> > tracer (I need to reset align_next to zero anyway even with the v1
> > design, that is a bug in the patch), and increment from that.
>
> I was only talking about doing this for the initial expiration, not on
> increment.
>
Ah, I misread "period" as "relative period", since the initial
absolute period is determined from the current time in the first cycle
of each thread.
> > 2. "cpu" makes a poor thread ID here. If my period is 1000us, and I
> > run on CPUs 0 and 100 with alignment 10, suddenly, the space between
> > the threads becomes 1000us, which is equivalent to 0us. I would need
> > to go through the cpuset and assign numbers from 0 to n to each CPU.
> > That would guarantee a fixed spacing of the threads independent of
> > when the threads wake up in the first cycle (unlike the v1 design),
> > but it would make the implementation more complex, since I would have
> > to store the numbers.
>
> Right, I was thinking of just a few CPUs missing not being a big deal,
> but on big systems with only a few CPUs running the test it does
> matter.
>
My point is mostly that the spacing of the threads shouldn't depend on
the CPU numbers. One has to make sure the alignment doesn't overflow
the period anyway if they want to have completely time-isolated
wake-ups.
> Instead of assigning numbers, could you just loop over each CPU's
> tlat->abs_period and set the initial expiration with appropriate
> offset (prior to starting any of the threads)? Then the thread would
> not need to care about anything other than the usual increment.
>
> > If I implemented both of those ideas, the interaction between the CPUs
> > can indeed be gotten rid of. I'm not sure if it is a better solution,
> > though. Another motivation of recording the first thread wake-up was
> > that when using user threads, the first thread might be created some
> > time after the tracer is enabled, and I did not want to have a large
> > gap that would have to be corrected by the while loop at the end of
> > wait_next_period().
>
> What is the actual concerning impact here?
>
> If we want to be really paranoid we could check for pending signals
> during the loop, in case userspace delayed so long (with a very short
> period) that the user has a hard time with ctrl+c and such... but that
> could happen already if userspace does something silly (e.g. stopped
> by a debugger?) between loops.
>
The while loop is designed only to handle "small" time differences,
with respect to the relative period. When using timerlat manually with
a user workload, it might take the user a few seconds/seconds/hours
before they start the user process (typing the command line, or if the
user e.g. has a snack or coffee in between), which has to be corrected
by the while loop. This does not interact well with a low period.
Consider the following scenario, assuming the initial absolute period
is set on timerlat tracer enablement:
1. The user enables the timerlat tracer with NO_OSNOISE_WORKLOAD and
100us period.
2. The user steps away for 1 hour.
3. After 10 seconds, tlat->abs_period is 3 600 000 000us in the past.
The while loop starts incrementing tlat->abs_period by 100us, taking
36 000 000 loops. If one iteration takes 10 CPU cycles on a 1GHz CPU,
the while loop itself will take 360us (which is >100us).
4. The timerlat thread never wakes up, since the wake-up time even
after the correction is in the past.
This is much more reasonable than the user stopping the thread inside
the while loop. Actually, this scenario can already happen without
alignment, since the scheduler might preempt the thread inside the
while loop for more than the period - but that is a separate issue.
Also, the current implementation is relatively simple (and hopefully
also easy to understand with the comments in v2), so my idea is that
we can use it for now, and if we want deterministing alignment in the
future, we can always improve it.
> > Good idea, thanks! In general, I'm not expecting the user to change
> > timerlat parameters during a measurement - but it is supported, and
> > should be documented.
>
> Maybe better to phrase it as "not guaranteed to take effect
> immediately" :-)
>
I think we can afford to be less vague than that here :) something
like, "setting the timerlat_align_us option will take affect upon next
timerlat tracer start".
> > I used it in cyclictest to measure the overhead of a large number of
> > threads waking up at the same time. Similarly, a non-zero alignment
> > will get rid of most of that overhead. Without alignment set, the
> > thread wake-ups offsets are semi-random, depending on how the threads
> > wake up, which might lead to inconsistent results where one run has
> > good numbers and another run bad numbers, since the alignment is
> > determined in the first cycle.
>
> OK, I was viewing the staggering as the main point, but I see how the
> alignment itself helps too.
>
> Is there a use case for not always doing the alignment?
> Other than people asking why their numbers suddenly got worse...
>
Yes - to simulate the default behavior of cyclictest without
-A/--aligned, and of multi-thread cyclic workloads that do not align
their threads respectively. Even if we wanted to always use the
alignment, it should not default to 0 IMHO, so that users don't see a
degradation like you mention.
> > next_abs_period is basically just the ktime_t variant of
> > tlat->abs_period for local calculations of the next period inside
> > wait_next_period(). Its only purpose is the ktime_compare() call that
> > increments tlat->abs_period by the period until it lands into the
> > future, if it happens to be in the past. This is necessary to do for
> > both a regular cycle (which might take long due to noise) and the
> > first cycle with alignment (because the other thread's first wake up
> > might be late), so it has to be set in the new code as well,
> > otherwise, the while loop won't see the time is in the past.
>
> Oh, I missed the unit difference (though it's basically just a typedef
> at this point).
>
> > I agree that this part of the code is confusing. There is also a
> > field, timerlat_variables.rel_period (tlat->rel_period), that is not
> > used anywhere, since the relative period is pulled out of
> > osnoise_variables. Something like this would be easier to read and
> > comprehend, IMHO:
>
> Yeah, I noticed that as well... we should remove it if we're not going
> to use it.
>
Yeah.
> > /*
> > * wait_next_period - Wait for the next period for timerlat
> > */
> > static int wait_next_period(struct timerlat_variables *tlat)
> > {
> > ktime_t now;
> > u64 rel_period = osnoise_data.timerlat_period * 1000;
> >
> > now = hrtimer_cb_get_time(&tlat->timer);
> >
> > /*
> > * Set the next abs_period.
> > */
> > tlat->abs_period += rel_period;
> >
> > /*
> > * If the new abs_period is in the past, skip the activation.
> > */
> > while (ktime_compare(now, ns_to_ktime(tlat->abs_period) > 0) {
> > next_abs_period = ns_to_ktime(tlat->abs_period + rel_period);
> > tlat->abs_period = (u64) ktime_to_ns(next_abs_period);
> > }
> >
> > set_current_state(TASK_INTERRUPTIBLE);
> >
> > hrtimer_start(&tlat->timer, next_abs_period, HRTIMER_MODE_ABS_PINNED_HARD);
> > schedule();
> > return 1;
> > }
> >
> > (Excluding the changes from this patch.) What do you think?
>
> Why can't we just make tlat->abs_period and every other time variable
> in this file be ktime_t? Other than atomic stuff if we do go that
> route.
>
> Not saying that that should hold up this patch, just an idea to simplify things.
>
The reason for that is that the code does arithmetic directly on the
ns unit form of the time, without the need to use ktime_add(). I don't
see anything on top of that. I see ktime_add(x, y) is just x + y
nowadays, so that would work.
Tomas
^ permalink raw reply
* Re: [PATCH V2] tracing: Revert "tracing: Remove pid in task_rename tracing output"
From: Steven Rostedt @ 2026-03-06 15:06 UTC (permalink / raw)
To: Xuewen Yan
Cc: mhiramat, mathieu.desnoyers, elver, kees, lorenzo.stoakes,
brauner, schuster.simon, david, linux-kernel, linux-trace-kernel,
guohua.yan, ke.wang, xuewen.yan94, jing.xia
In-Reply-To: <20260306075954.4533-1-xuewen.yan@unisoc.com>
On Fri, 6 Mar 2026 15:59:54 +0800
Xuewen Yan <xuewen.yan@unisoc.com> wrote:
> This reverts commit e3f6a42272e028c46695acc83fc7d7c42f2750ad.
>
> The commit says that the tracepoint only deals with the current task,
> however the following case is not current task:
>
> comm_write() {
> p = get_proc_task(inode);
> if (!p)
> return -ESRCH;
>
> if (same_thread_group(current, p))
> set_task_comm(p, buffer);
> }
> where set_task_comm() calls __set_task_comm() which records
> the update of p and not current.
>
> So revert the patch to show pid.
>
> Fixes: e3f6a42272e0 ("tracing: Remove pid in task_rename tracing output")
> Reported-by: Guohua Yan <guohua.yan@unisoc.com>
> Signed-off-by: Xuewen Yan <xuewen.yan@unisoc.com>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
-- Steve
> ---
> v2:
> - update commit message (Steven)
> ---
> include/trace/events/task.h | 7 +++++--
> 1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/include/trace/events/task.h b/include/trace/events/task.h
> index 4f0759634306..b9a129eb54d9 100644
> --- a/include/trace/events/task.h
> +++ b/include/trace/events/task.h
> @@ -38,19 +38,22 @@ TRACE_EVENT(task_rename,
> TP_ARGS(task, comm),
>
> TP_STRUCT__entry(
> + __field( pid_t, pid)
> __array( char, oldcomm, TASK_COMM_LEN)
> __array( char, newcomm, TASK_COMM_LEN)
> __field( short, oom_score_adj)
> ),
>
> TP_fast_assign(
> + __entry->pid = task->pid;
> memcpy(entry->oldcomm, task->comm, TASK_COMM_LEN);
> strscpy(entry->newcomm, comm, TASK_COMM_LEN);
> __entry->oom_score_adj = task->signal->oom_score_adj;
> ),
>
> - TP_printk("oldcomm=%s newcomm=%s oom_score_adj=%hd",
> - __entry->oldcomm, __entry->newcomm, __entry->oom_score_adj)
> + TP_printk("pid=%d oldcomm=%s newcomm=%s oom_score_adj=%hd",
> + __entry->pid, __entry->oldcomm,
> + __entry->newcomm, __entry->oom_score_adj)
> );
>
> /**
^ permalink raw reply
* Re: [PATCH v5 2/3] ring-buffer: Handle RB_MISSED_* flags on commit field correctly
From: Steven Rostedt @ 2026-03-06 14:59 UTC (permalink / raw)
To: Masami Hiramatsu (Google)
Cc: Mathieu Desnoyers, linux-kernel, linux-trace-kernel
In-Reply-To: <20260306174609.d387b67d04e05328ea262fba@kernel.org>
On Fri, 6 Mar 2026 17:46:09 +0900
Masami Hiramatsu (Google) <mhiramat@kernel.org> wrote:
> On Thu, 5 Mar 2026 13:03:48 -0500
> Steven Rostedt <rostedt@goodmis.org> wrote:
>
> > On Thu, 26 Feb 2026 22:38:43 +0900
> > "Masami Hiramatsu (Google)" <mhiramat@kernel.org> wrote:
> >
> > > From: Masami Hiramatsu (Google) <mhiramat@kernel.org>
> > >
> > > Since the MSBs of rb_data_page::commit are used for storing
> > > RB_MISSED_EVENTS and RB_MISSED_STORED, we need to mask out those bits
> > > when it is used for finding the size of data pages.
> > >
> > > Fixes: 5f3b6e839f3c ("ring-buffer: Validate boot range memory events")
> > > Fixes: 5b7be9c709e1 ("ring-buffer: Add test to validate the time stamp deltas")
> > > Cc: stable@vger.kernel.org
> >
> > This is unneeded for the current way things work.
> >
> > The missed events flags are added when a page is read, so the commits in
> > the write buffer should never have those flags set. If they did, the ring
> > buffer code itself would break.
>
> Hmm, but commit ca296d32ece3 ("tracing: ring_buffer: Rewind persistent
> ring buffer on reboot") may change it. Maybe we should treat it while
> unwinding it?
Might change what?
>
> >
> > But as patch 3 is adding a flag, you should likely merge this and patch 3
> > together, as the only way that flag would get set is if the validator set
> > it on a previous boot. And then this would be needed for subsequent boots
> > that did not reset the buffer.
>
> It is OK to combine these 2 patches. But my question is that when the flag
> must be checked and when it must be ignored. Since the flags are encoded
> to commit, if that is used for limiting or indexing inside the page,
> we must mask the flag or check the max size to avoid accessing outside of
> the subpage.
>
> >
> > Hmm, I don't think we even need to do that! Because if it is set, it would
> > simply warn again that a page is invalid, and I think we *want* that! As it
> > would preserve that pages were invalid and not be cleared with a simple
> > reboot.
>
> OK, then I don't mark it, but just invalidate the subpage.
No, I mean you can mark it, but then just have the validator skip it.
Something like:
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 156ed19fb569..c98ab86cf384 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -1950,6 +1951,10 @@ static void rb_meta_validate_events(struct ring_buffer_per_cpu *cpu_buffer)
rb_dec_page(&head_page);
for (i = 0; i < meta->nr_subbufs + 1; i++, rb_dec_page(&head_page)) {
+ /* Skip if this buffer was flagged as bad before */
+ if (local_read(&head_page->page->commit) == RB_MISSED_EVENTS)
+ continue;
+
/* Rewind until tail (writer) page. */
if (head_page == cpu_buffer->tail_page)
break;
^ permalink raw reply related
* [PATCH v13 32/32] fixup! tracing: Add a trace remote module for testing
From: Vincent Donnefort @ 2026-03-06 14:35 UTC (permalink / raw)
To: rostedt, mhiramat, mathieu.desnoyers, linux-trace-kernel, maz,
oliver.upton, joey.gouly, suzuki.poulose, yuzenghui
Cc: kvmarm, linux-arm-kernel, jstultz, qperret, will, aneesh.kumar,
kernel-team, linux-kernel, Vincent Donnefort
In-Reply-To: <20260306143536.339777-1-vdonnefort@google.com>
diff --git a/kernel/trace/remote_test.c b/kernel/trace/remote_test.c
index 791128d7fd00..6c1b7701ddae 100644
--- a/kernel/trace/remote_test.c
+++ b/kernel/trace/remote_test.c
@@ -28,11 +28,11 @@ static int remote_test_load_simple_rb(int cpu, struct ring_buffer_desc *rb_desc)
struct simple_buffer_page *bpages;
int ret = -ENOMEM;
- cpu_buffer = kzalloc_obj(*cpu_buffer);
+ cpu_buffer = kmalloc_obj(*cpu_buffer);
if (!cpu_buffer)
return ret;
- bpages = kmalloc_array(rb_desc->nr_page_va, sizeof(*bpages), GFP_KERNEL);
+ bpages = kmalloc_objs(*bpages, rb_desc->nr_page_va);
if (!bpages)
goto err_free_cpu_buffer;
--
2.53.0.473.g4a7958ca14-goog
^ permalink raw reply related
* [PATCH v13 31/32] fixup! tracing: Add a trace remote module for testing
From: Vincent Donnefort @ 2026-03-06 14:35 UTC (permalink / raw)
To: rostedt, mhiramat, mathieu.desnoyers, linux-trace-kernel, maz,
oliver.upton, joey.gouly, suzuki.poulose, yuzenghui
Cc: kvmarm, linux-arm-kernel, jstultz, qperret, will, aneesh.kumar,
kernel-team, linux-kernel, Vincent Donnefort
In-Reply-To: <20260306143536.339777-1-vdonnefort@google.com>
diff --git a/kernel/trace/remote_test.c b/kernel/trace/remote_test.c
index e5023b9d2611..791128d7fd00 100644
--- a/kernel/trace/remote_test.c
+++ b/kernel/trace/remote_test.c
@@ -28,7 +28,7 @@ static int remote_test_load_simple_rb(int cpu, struct ring_buffer_desc *rb_desc)
struct simple_buffer_page *bpages;
int ret = -ENOMEM;
- cpu_buffer = kmalloc(sizeof(*cpu_buffer), GFP_KERNEL);
+ cpu_buffer = kzalloc_obj(*cpu_buffer);
if (!cpu_buffer)
return ret;
--
2.53.0.473.g4a7958ca14-goog
^ permalink raw reply related
* [PATCH v13 30/32] tracing: selftests: Add hypervisor trace remote tests
From: Vincent Donnefort @ 2026-03-06 14:35 UTC (permalink / raw)
To: rostedt, mhiramat, mathieu.desnoyers, linux-trace-kernel, maz,
oliver.upton, joey.gouly, suzuki.poulose, yuzenghui
Cc: kvmarm, linux-arm-kernel, jstultz, qperret, will, aneesh.kumar,
kernel-team, linux-kernel, Vincent Donnefort, Shuah Khan,
linux-kselftest
In-Reply-To: <20260306143536.339777-1-vdonnefort@google.com>
Run the trace remote selftests with the trace remote 'hypervisor', This
trace remote is most likely created when the arm64 KVM nVHE/pKVM
hypervisor is in use.
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: linux-kselftest@vger.kernel.org
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
diff --git a/tools/testing/selftests/ftrace/test.d/remotes/hypervisor/buffer_size.tc b/tools/testing/selftests/ftrace/test.d/remotes/hypervisor/buffer_size.tc
new file mode 100644
index 000000000000..64bf859d6406
--- /dev/null
+++ b/tools/testing/selftests/ftrace/test.d/remotes/hypervisor/buffer_size.tc
@@ -0,0 +1,11 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+# description: Test hypervisor trace buffer size
+# requires: remotes/hypervisor/write_event
+
+SOURCE_REMOTE_TEST=1
+. $TEST_DIR/remotes/buffer_size.tc
+
+set -e
+setup_remote "hypervisor"
+test_buffer_size
diff --git a/tools/testing/selftests/ftrace/test.d/remotes/hypervisor/reset.tc b/tools/testing/selftests/ftrace/test.d/remotes/hypervisor/reset.tc
new file mode 100644
index 000000000000..7fe3b09b34e3
--- /dev/null
+++ b/tools/testing/selftests/ftrace/test.d/remotes/hypervisor/reset.tc
@@ -0,0 +1,11 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+# description: Test hypervisor trace buffer reset
+# requires: remotes/hypervisor/write_event
+
+SOURCE_REMOTE_TEST=1
+. $TEST_DIR/remotes/reset.tc
+
+set -e
+setup_remote "hypervisor"
+test_reset
diff --git a/tools/testing/selftests/ftrace/test.d/remotes/hypervisor/trace.tc b/tools/testing/selftests/ftrace/test.d/remotes/hypervisor/trace.tc
new file mode 100644
index 000000000000..b937c19ca7f9
--- /dev/null
+++ b/tools/testing/selftests/ftrace/test.d/remotes/hypervisor/trace.tc
@@ -0,0 +1,11 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+# description: Test hypervisor non-consuming trace read
+# requires: remotes/hypervisor/write_event
+
+SOURCE_REMOTE_TEST=1
+. $TEST_DIR/remotes/trace.tc
+
+set -e
+setup_remote "hypervisor"
+test_trace
diff --git a/tools/testing/selftests/ftrace/test.d/remotes/hypervisor/trace_pipe.tc b/tools/testing/selftests/ftrace/test.d/remotes/hypervisor/trace_pipe.tc
new file mode 100644
index 000000000000..66aa1b76c147
--- /dev/null
+++ b/tools/testing/selftests/ftrace/test.d/remotes/hypervisor/trace_pipe.tc
@@ -0,0 +1,11 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+# description: Test hypervisor consuming trace read
+# requires: remotes/hypervisor/write_event
+
+SOURCE_REMOTE_TEST=1
+. $TEST_DIR/remotes/trace_pipe.tc
+
+set -e
+setup_remote "hypervisor"
+test_trace_pipe
diff --git a/tools/testing/selftests/ftrace/test.d/remotes/hypervisor/unloading.tc b/tools/testing/selftests/ftrace/test.d/remotes/hypervisor/unloading.tc
new file mode 100644
index 000000000000..1dafde3414ab
--- /dev/null
+++ b/tools/testing/selftests/ftrace/test.d/remotes/hypervisor/unloading.tc
@@ -0,0 +1,11 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+# description: Test hypervisor trace buffer unloading
+# requires: remotes/hypervisor/write_event
+
+SOURCE_REMOTE_TEST=1
+. $TEST_DIR/remotes/unloading.tc
+
+set -e
+setup_remote "hypervisor"
+test_unloading
--
2.53.0.473.g4a7958ca14-goog
^ permalink raw reply related
* [PATCH v13 29/32] KVM: arm64: Add selftest event support to nVHE/pKVM hyp
From: Vincent Donnefort @ 2026-03-06 14:35 UTC (permalink / raw)
To: rostedt, mhiramat, mathieu.desnoyers, linux-trace-kernel, maz,
oliver.upton, joey.gouly, suzuki.poulose, yuzenghui
Cc: kvmarm, linux-arm-kernel, jstultz, qperret, will, aneesh.kumar,
kernel-team, linux-kernel, Vincent Donnefort
In-Reply-To: <20260306143536.339777-1-vdonnefort@google.com>
Add a selftest event that can be triggered from a `write_event` tracefs
file. This intends to be used by trace remote selftests.
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
index 47d250436f8c..c8eb992d3ac8 100644
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h
@@ -96,6 +96,7 @@ enum __kvm_host_smccc_func {
__KVM_HOST_SMCCC_FUNC___tracing_update_clock,
__KVM_HOST_SMCCC_FUNC___tracing_reset,
__KVM_HOST_SMCCC_FUNC___tracing_enable_event,
+ __KVM_HOST_SMCCC_FUNC___tracing_write_event,
};
#define DECLARE_KVM_VHE_SYM(sym) extern char sym[]
diff --git a/arch/arm64/include/asm/kvm_hypevents.h b/arch/arm64/include/asm/kvm_hypevents.h
index 221a1dacb2f0..743c49bd878f 100644
--- a/arch/arm64/include/asm/kvm_hypevents.h
+++ b/arch/arm64/include/asm/kvm_hypevents.h
@@ -46,4 +46,15 @@ HYP_EVENT(hyp_exit,
),
HE_PRINTK("reason=%s vcpu=%d", __hyp_enter_exit_reason_str(__entry->reason), __entry->vcpu)
);
+
+HYP_EVENT(selftest,
+ HE_PROTO(u64 id),
+ HE_STRUCT(
+ he_field(u64, id)
+ ),
+ HE_ASSIGN(
+ __entry->id = id;
+ ),
+ RE_PRINTK("id=%llu", __entry->id)
+);
#endif
diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
index 547d63679022..eff9cb208627 100644
--- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c
+++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
@@ -643,6 +643,13 @@ static void handle___tracing_enable_event(struct kvm_cpu_context *host_ctxt)
cpu_reg(host_ctxt, 1) = __tracing_enable_event(id, enable);
}
+static void handle___tracing_write_event(struct kvm_cpu_context *host_ctxt)
+{
+ DECLARE_REG(u64, id, host_ctxt, 1);
+
+ trace_selftest(id);
+}
+
typedef void (*hcall_t)(struct kvm_cpu_context *);
#define HANDLE_FUNC(x) [__KVM_HOST_SMCCC_FUNC_##x] = (hcall_t)handle_##x
@@ -691,6 +698,7 @@ static const hcall_t host_hcall[] = {
HANDLE_FUNC(__tracing_update_clock),
HANDLE_FUNC(__tracing_reset),
HANDLE_FUNC(__tracing_enable_event),
+ HANDLE_FUNC(__tracing_write_event),
};
static void handle_host_hcall(struct kvm_cpu_context *host_ctxt)
diff --git a/arch/arm64/kvm/hyp_trace.c b/arch/arm64/kvm/hyp_trace.c
index 1ad6a55ba95c..c1e28f6581ab 100644
--- a/arch/arm64/kvm/hyp_trace.c
+++ b/arch/arm64/kvm/hyp_trace.c
@@ -348,8 +348,30 @@ static int hyp_trace_clock_show(struct seq_file *m, void *v)
}
DEFINE_SHOW_ATTRIBUTE(hyp_trace_clock);
+static ssize_t hyp_trace_write_event_write(struct file *f, const char __user *ubuf,
+ size_t cnt, loff_t *pos)
+{
+ unsigned long val;
+ int ret;
+
+ ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
+ if (ret)
+ return ret;
+
+ kvm_call_hyp_nvhe(__tracing_write_event, val);
+
+ return cnt;
+}
+
+static const struct file_operations hyp_trace_write_event_fops = {
+ .write = hyp_trace_write_event_write,
+};
+
static int hyp_trace_init_tracefs(struct dentry *d, void *priv)
{
+ if (!tracefs_create_file("write_event", 0200, d, NULL, &hyp_trace_write_event_fops))
+ return -ENOMEM;
+
return tracefs_create_file("trace_clock", 0440, d, NULL, &hyp_trace_clock_fops) ?
0 : -ENOMEM;
}
--
2.53.0.473.g4a7958ca14-goog
^ permalink raw reply related
* [PATCH v13 28/32] KVM: arm64: Add hyp_enter/hyp_exit events to nVHE/pKVM hyp
From: Vincent Donnefort @ 2026-03-06 14:35 UTC (permalink / raw)
To: rostedt, mhiramat, mathieu.desnoyers, linux-trace-kernel, maz,
oliver.upton, joey.gouly, suzuki.poulose, yuzenghui
Cc: kvmarm, linux-arm-kernel, jstultz, qperret, will, aneesh.kumar,
kernel-team, linux-kernel, Vincent Donnefort
In-Reply-To: <20260306143536.339777-1-vdonnefort@google.com>
The hyp_enter and hyp_exit events are logged by the hypervisor any time
it is entered and exited.
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 2ca264b3db5f..b50ac3bb4bc9 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -920,6 +920,9 @@ struct kvm_vcpu_arch {
/* Per-vcpu TLB for VNCR_EL2 -- NULL when !NV */
struct vncr_tlb *vncr_tlb;
+
+ /* Hyp-readable copy of kvm_vcpu::pid */
+ pid_t pid;
};
/*
diff --git a/arch/arm64/include/asm/kvm_hypevents.h b/arch/arm64/include/asm/kvm_hypevents.h
index d6e033c96c52..221a1dacb2f0 100644
--- a/arch/arm64/include/asm/kvm_hypevents.h
+++ b/arch/arm64/include/asm/kvm_hypevents.h
@@ -7,4 +7,43 @@
#include <nvhe/trace.h>
#endif
+#ifndef __HYP_ENTER_EXIT_REASON
+#define __HYP_ENTER_EXIT_REASON
+enum hyp_enter_exit_reason {
+ HYP_REASON_SMC,
+ HYP_REASON_HVC,
+ HYP_REASON_PSCI,
+ HYP_REASON_HOST_ABORT,
+ HYP_REASON_GUEST_EXIT,
+ HYP_REASON_ERET_HOST,
+ HYP_REASON_ERET_GUEST,
+ HYP_REASON_UNKNOWN /* Must be last */
+};
+#endif
+
+HYP_EVENT(hyp_enter,
+ HE_PROTO(struct kvm_cpu_context *host_ctxt, u8 reason),
+ HE_STRUCT(
+ he_field(u8, reason)
+ he_field(pid_t, vcpu)
+ ),
+ HE_ASSIGN(
+ __entry->reason = reason;
+ __entry->vcpu = __tracing_get_vcpu_pid(host_ctxt);
+ ),
+ HE_PRINTK("reason=%s vcpu=%d", __hyp_enter_exit_reason_str(__entry->reason), __entry->vcpu)
+);
+
+HYP_EVENT(hyp_exit,
+ HE_PROTO(struct kvm_cpu_context *host_ctxt, u8 reason),
+ HE_STRUCT(
+ he_field(u8, reason)
+ he_field(pid_t, vcpu)
+ ),
+ HE_ASSIGN(
+ __entry->reason = reason;
+ __entry->vcpu = __tracing_get_vcpu_pid(host_ctxt);
+ ),
+ HE_PRINTK("reason=%s vcpu=%d", __hyp_enter_exit_reason_str(__entry->reason), __entry->vcpu)
+);
#endif
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 87a3d28d5f0f..04c43c9eb764 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -707,6 +707,8 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
if (!cpumask_test_cpu(cpu, vcpu->kvm->arch.supported_cpus))
vcpu_set_on_unsupported_cpu(vcpu);
+
+ vcpu->arch.pid = pid_nr(vcpu->pid);
}
void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
diff --git a/arch/arm64/kvm/hyp/include/nvhe/arm-smccc.h b/arch/arm64/kvm/hyp/include/nvhe/arm-smccc.h
new file mode 100644
index 000000000000..1258bc84477f
--- /dev/null
+++ b/arch/arm64/kvm/hyp/include/nvhe/arm-smccc.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef __ARM64_KVM_HYP_NVHE_ARM_SMCCC_H__
+#define __ARM64_KVM_HYP_NVHE_ARM_SMCCC_H__
+
+#include <asm/kvm_hypevents.h>
+
+#include <linux/arm-smccc.h>
+
+#define hyp_smccc_1_1_smc(...) \
+ do { \
+ trace_hyp_exit(NULL, HYP_REASON_SMC); \
+ arm_smccc_1_1_smc(__VA_ARGS__); \
+ trace_hyp_enter(NULL, HYP_REASON_SMC); \
+ } while (0)
+
+#define hyp_smccc_1_2_smc(...) \
+ do { \
+ trace_hyp_exit(NULL, HYP_REASON_SMC); \
+ arm_smccc_1_2_smc(__VA_ARGS__); \
+ trace_hyp_enter(NULL, HYP_REASON_SMC); \
+ } while (0)
+
+#endif /* __ARM64_KVM_HYP_NVHE_ARM_SMCCC_H__ */
diff --git a/arch/arm64/kvm/hyp/include/nvhe/trace.h b/arch/arm64/kvm/hyp/include/nvhe/trace.h
index 802a18b77c56..8813ff250f8e 100644
--- a/arch/arm64/kvm/hyp/include/nvhe/trace.h
+++ b/arch/arm64/kvm/hyp/include/nvhe/trace.h
@@ -6,6 +6,18 @@
#include <asm/kvm_hyptrace.h>
+static inline pid_t __tracing_get_vcpu_pid(struct kvm_cpu_context *host_ctxt)
+{
+ struct kvm_vcpu *vcpu;
+
+ if (!host_ctxt)
+ host_ctxt = host_data_ptr(host_ctxt);
+
+ vcpu = host_ctxt->__hyp_running_vcpu;
+
+ return vcpu ? vcpu->arch.pid : 0;
+}
+
#define HE_PROTO(__args...) __args
#define HE_ASSIGN(__args...) __args
#define HE_STRUCT RE_STRUCT
diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c
index 94161ea1cd60..1af722771178 100644
--- a/arch/arm64/kvm/hyp/nvhe/ffa.c
+++ b/arch/arm64/kvm/hyp/nvhe/ffa.c
@@ -26,10 +26,10 @@
* the duration and are therefore serialised.
*/
-#include <linux/arm-smccc.h>
#include <linux/arm_ffa.h>
#include <asm/kvm_pkvm.h>
+#include <nvhe/arm-smccc.h>
#include <nvhe/ffa.h>
#include <nvhe/mem_protect.h>
#include <nvhe/memory.h>
@@ -147,7 +147,7 @@ static int ffa_map_hyp_buffers(u64 ffa_page_count)
{
struct arm_smccc_1_2_regs res;
- arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
+ hyp_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
.a0 = FFA_FN64_RXTX_MAP,
.a1 = hyp_virt_to_phys(hyp_buffers.tx),
.a2 = hyp_virt_to_phys(hyp_buffers.rx),
@@ -161,7 +161,7 @@ static int ffa_unmap_hyp_buffers(void)
{
struct arm_smccc_1_2_regs res;
- arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
+ hyp_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
.a0 = FFA_RXTX_UNMAP,
.a1 = HOST_FFA_ID,
}, &res);
@@ -172,7 +172,7 @@ static int ffa_unmap_hyp_buffers(void)
static void ffa_mem_frag_tx(struct arm_smccc_1_2_regs *res, u32 handle_lo,
u32 handle_hi, u32 fraglen, u32 endpoint_id)
{
- arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
+ hyp_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
.a0 = FFA_MEM_FRAG_TX,
.a1 = handle_lo,
.a2 = handle_hi,
@@ -184,7 +184,7 @@ static void ffa_mem_frag_tx(struct arm_smccc_1_2_regs *res, u32 handle_lo,
static void ffa_mem_frag_rx(struct arm_smccc_1_2_regs *res, u32 handle_lo,
u32 handle_hi, u32 fragoff)
{
- arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
+ hyp_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
.a0 = FFA_MEM_FRAG_RX,
.a1 = handle_lo,
.a2 = handle_hi,
@@ -196,7 +196,7 @@ static void ffa_mem_frag_rx(struct arm_smccc_1_2_regs *res, u32 handle_lo,
static void ffa_mem_xfer(struct arm_smccc_1_2_regs *res, u64 func_id, u32 len,
u32 fraglen)
{
- arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
+ hyp_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
.a0 = func_id,
.a1 = len,
.a2 = fraglen,
@@ -206,7 +206,7 @@ static void ffa_mem_xfer(struct arm_smccc_1_2_regs *res, u64 func_id, u32 len,
static void ffa_mem_reclaim(struct arm_smccc_1_2_regs *res, u32 handle_lo,
u32 handle_hi, u32 flags)
{
- arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
+ hyp_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
.a0 = FFA_MEM_RECLAIM,
.a1 = handle_lo,
.a2 = handle_hi,
@@ -216,7 +216,7 @@ static void ffa_mem_reclaim(struct arm_smccc_1_2_regs *res, u32 handle_lo,
static void ffa_retrieve_req(struct arm_smccc_1_2_regs *res, u32 len)
{
- arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
+ hyp_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
.a0 = FFA_FN64_MEM_RETRIEVE_REQ,
.a1 = len,
.a2 = len,
@@ -225,7 +225,7 @@ static void ffa_retrieve_req(struct arm_smccc_1_2_regs *res, u32 len)
static void ffa_rx_release(struct arm_smccc_1_2_regs *res)
{
- arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
+ hyp_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
.a0 = FFA_RX_RELEASE,
}, res);
}
@@ -728,7 +728,7 @@ static int hyp_ffa_post_init(void)
size_t min_rxtx_sz;
struct arm_smccc_1_2_regs res;
- arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs){
+ hyp_smccc_1_2_smc(&(struct arm_smccc_1_2_regs){
.a0 = FFA_ID_GET,
}, &res);
if (res.a0 != FFA_SUCCESS)
@@ -737,7 +737,7 @@ static int hyp_ffa_post_init(void)
if (res.a2 != HOST_FFA_ID)
return -EINVAL;
- arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs){
+ hyp_smccc_1_2_smc(&(struct arm_smccc_1_2_regs){
.a0 = FFA_FEATURES,
.a1 = FFA_FN64_RXTX_MAP,
}, &res);
@@ -788,7 +788,7 @@ static void do_ffa_version(struct arm_smccc_1_2_regs *res,
* first if TEE supports it.
*/
if (FFA_MINOR_VERSION(ffa_req_version) < FFA_MINOR_VERSION(hyp_ffa_version)) {
- arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
+ hyp_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
.a0 = FFA_VERSION,
.a1 = ffa_req_version,
}, res);
@@ -824,7 +824,7 @@ static void do_ffa_part_get(struct arm_smccc_1_2_regs *res,
goto out_unlock;
}
- arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
+ hyp_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
.a0 = FFA_PARTITION_INFO_GET,
.a1 = uuid0,
.a2 = uuid1,
@@ -939,7 +939,7 @@ int hyp_ffa_init(void *pages)
if (kvm_host_psci_config.smccc_version < ARM_SMCCC_VERSION_1_2)
return 0;
- arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
+ hyp_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) {
.a0 = FFA_VERSION,
.a1 = FFA_VERSION_1_2,
}, &res);
diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
index fc5953f31b4b..547d63679022 100644
--- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c
+++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
@@ -12,6 +12,7 @@
#include <asm/kvm_emulate.h>
#include <asm/kvm_host.h>
#include <asm/kvm_hyp.h>
+#include <asm/kvm_hypevents.h>
#include <asm/kvm_mmu.h>
#include <nvhe/ffa.h>
@@ -137,6 +138,8 @@ static void flush_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu)
hyp_vcpu->vcpu.arch.vsesr_el2 = host_vcpu->arch.vsesr_el2;
hyp_vcpu->vcpu.arch.vgic_cpu.vgic_v3 = host_vcpu->arch.vgic_cpu.vgic_v3;
+
+ hyp_vcpu->vcpu.arch.pid = host_vcpu->arch.pid;
}
static void sync_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu)
@@ -728,7 +731,9 @@ static void handle_host_hcall(struct kvm_cpu_context *host_ctxt)
static void default_host_smc_handler(struct kvm_cpu_context *host_ctxt)
{
+ trace_hyp_exit(host_ctxt, HYP_REASON_SMC);
__kvm_hyp_host_forward_smc(host_ctxt);
+ trace_hyp_enter(host_ctxt, HYP_REASON_SMC);
}
static void handle_host_smc(struct kvm_cpu_context *host_ctxt)
@@ -815,15 +820,19 @@ void handle_trap(struct kvm_cpu_context *host_ctxt)
{
u64 esr = read_sysreg_el2(SYS_ESR);
+
switch (ESR_ELx_EC(esr)) {
case ESR_ELx_EC_HVC64:
+ trace_hyp_enter(host_ctxt, HYP_REASON_HVC);
handle_host_hcall(host_ctxt);
break;
case ESR_ELx_EC_SMC64:
+ trace_hyp_enter(host_ctxt, HYP_REASON_SMC);
handle_host_smc(host_ctxt);
break;
case ESR_ELx_EC_IABT_LOW:
case ESR_ELx_EC_DABT_LOW:
+ trace_hyp_enter(host_ctxt, HYP_REASON_HOST_ABORT);
handle_host_mem_abort(host_ctxt);
break;
case ESR_ELx_EC_SYS64:
@@ -833,4 +842,6 @@ void handle_trap(struct kvm_cpu_context *host_ctxt)
default:
BUG();
}
+
+ trace_hyp_exit(host_ctxt, HYP_REASON_ERET_HOST);
}
diff --git a/arch/arm64/kvm/hyp/nvhe/psci-relay.c b/arch/arm64/kvm/hyp/nvhe/psci-relay.c
index c3e196fb8b18..ab4c7bddb163 100644
--- a/arch/arm64/kvm/hyp/nvhe/psci-relay.c
+++ b/arch/arm64/kvm/hyp/nvhe/psci-relay.c
@@ -6,11 +6,12 @@
#include <asm/kvm_asm.h>
#include <asm/kvm_hyp.h>
+#include <asm/kvm_hypevents.h>
#include <asm/kvm_mmu.h>
-#include <linux/arm-smccc.h>
#include <linux/kvm_host.h>
#include <uapi/linux/psci.h>
+#include <nvhe/arm-smccc.h>
#include <nvhe/memory.h>
#include <nvhe/trap_handler.h>
@@ -65,7 +66,7 @@ static unsigned long psci_call(unsigned long fn, unsigned long arg0,
{
struct arm_smccc_res res;
- arm_smccc_1_1_smc(fn, arg0, arg1, arg2, &res);
+ hyp_smccc_1_1_smc(fn, arg0, arg1, arg2, &res);
return res.a0;
}
@@ -206,6 +207,7 @@ asmlinkage void __noreturn __kvm_host_psci_cpu_entry(bool is_cpu_on)
struct kvm_cpu_context *host_ctxt;
host_ctxt = host_data_ptr(host_ctxt);
+ trace_hyp_enter(host_ctxt, HYP_REASON_PSCI);
if (is_cpu_on)
boot_args = this_cpu_ptr(&cpu_on_args);
@@ -221,6 +223,7 @@ asmlinkage void __noreturn __kvm_host_psci_cpu_entry(bool is_cpu_on)
write_sysreg_el1(INIT_SCTLR_EL1_MMU_OFF, SYS_SCTLR);
write_sysreg(INIT_PSTATE_EL1, SPSR_EL2);
+ trace_hyp_exit(host_ctxt, HYP_REASON_PSCI);
__host_enter(host_ctxt);
}
diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c
index 779089e42681..ca60721501d1 100644
--- a/arch/arm64/kvm/hyp/nvhe/switch.c
+++ b/arch/arm64/kvm/hyp/nvhe/switch.c
@@ -7,7 +7,6 @@
#include <hyp/switch.h>
#include <hyp/sysreg-sr.h>
-#include <linux/arm-smccc.h>
#include <linux/kvm_host.h>
#include <linux/types.h>
#include <linux/jump_label.h>
@@ -21,6 +20,7 @@
#include <asm/kvm_asm.h>
#include <asm/kvm_emulate.h>
#include <asm/kvm_hyp.h>
+#include <asm/kvm_hypevents.h>
#include <asm/kvm_mmu.h>
#include <asm/fpsimd.h>
#include <asm/debug-monitors.h>
@@ -308,10 +308,13 @@ int __kvm_vcpu_run(struct kvm_vcpu *vcpu)
__debug_switch_to_guest(vcpu);
do {
+ trace_hyp_exit(host_ctxt, HYP_REASON_ERET_GUEST);
+
/* Jump in the fire! */
exit_code = __guest_enter(vcpu);
/* And we're baaack! */
+ trace_hyp_enter(host_ctxt, HYP_REASON_GUEST_EXIT);
} while (fixup_guest_exit(vcpu, &exit_code));
__sysreg_save_state_nvhe(guest_ctxt);
diff --git a/arch/arm64/kvm/hyp_trace.c b/arch/arm64/kvm/hyp_trace.c
index 0144cd26703e..1ad6a55ba95c 100644
--- a/arch/arm64/kvm/hyp_trace.c
+++ b/arch/arm64/kvm/hyp_trace.c
@@ -364,8 +364,26 @@ static struct trace_remote_callbacks trace_remote_callbacks = {
.enable_event = hyp_trace_enable_event,
};
+static const char *__hyp_enter_exit_reason_str(u8 reason);
+
#include <asm/kvm_define_hypevents.h>
+static const char *__hyp_enter_exit_reason_str(u8 reason)
+{
+ static const char strs[][12] = {
+ "smc",
+ "hvc",
+ "psci",
+ "host_abort",
+ "guest_exit",
+ "eret_host",
+ "eret_guest",
+ "unknown",
+ };
+
+ return strs[min(reason, HYP_REASON_UNKNOWN)];
+}
+
static void __init hyp_trace_init_events(void)
{
struct hyp_event_id *hyp_event_id = __hyp_event_ids_start;
--
2.53.0.473.g4a7958ca14-goog
^ permalink raw reply related
* [PATCH v13 27/32] KVM: arm64: Add event support to the nVHE/pKVM hyp and trace remote
From: Vincent Donnefort @ 2026-03-06 14:35 UTC (permalink / raw)
To: rostedt, mhiramat, mathieu.desnoyers, linux-trace-kernel, maz,
oliver.upton, joey.gouly, suzuki.poulose, yuzenghui
Cc: kvmarm, linux-arm-kernel, jstultz, qperret, will, aneesh.kumar,
kernel-team, linux-kernel, Vincent Donnefort
In-Reply-To: <20260306143536.339777-1-vdonnefort@google.com>
Allow the creation of hypervisor and trace remote events with a single
macro HYP_EVENT(). That macro expands in the kernel side to add all
the required declarations (based on REMOTE_EVENT()) as well as in the
hypervisor side to create the trace_<event>() function.
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
index 66abf77cf371..47d250436f8c 100644
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h
@@ -95,6 +95,7 @@ enum __kvm_host_smccc_func {
__KVM_HOST_SMCCC_FUNC___tracing_swap_reader,
__KVM_HOST_SMCCC_FUNC___tracing_update_clock,
__KVM_HOST_SMCCC_FUNC___tracing_reset,
+ __KVM_HOST_SMCCC_FUNC___tracing_enable_event,
};
#define DECLARE_KVM_VHE_SYM(sym) extern char sym[]
diff --git a/arch/arm64/include/asm/kvm_define_hypevents.h b/arch/arm64/include/asm/kvm_define_hypevents.h
new file mode 100644
index 000000000000..77d6790252a6
--- /dev/null
+++ b/arch/arm64/include/asm/kvm_define_hypevents.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#define REMOTE_EVENT_INCLUDE_FILE arch/arm64/include/asm/kvm_hypevents.h
+
+#define REMOTE_EVENT_SECTION "_hyp_events"
+
+#define HE_STRUCT(__args) __args
+#define HE_PRINTK(__args...) __args
+#define he_field re_field
+
+#define HYP_EVENT(__name, __proto, __struct, __assign, __printk) \
+ REMOTE_EVENT(__name, 0, RE_STRUCT(__struct), RE_PRINTK(__printk))
+
+#define HYP_EVENT_MULTI_READ
+#include <trace/define_remote_events.h>
+#undef HYP_EVENT_MULTI_READ
diff --git a/arch/arm64/include/asm/kvm_hypevents.h b/arch/arm64/include/asm/kvm_hypevents.h
new file mode 100644
index 000000000000..d6e033c96c52
--- /dev/null
+++ b/arch/arm64/include/asm/kvm_hypevents.h
@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#if !defined(__ARM64_KVM_HYPEVENTS_H_) || defined(HYP_EVENT_MULTI_READ)
+#define __ARM64_KVM_HYPEVENTS_H_
+
+#ifdef __KVM_NVHE_HYPERVISOR__
+#include <nvhe/trace.h>
+#endif
+
+#endif
diff --git a/arch/arm64/include/asm/kvm_hyptrace.h b/arch/arm64/include/asm/kvm_hyptrace.h
index 9c30a479bc36..de133b735f72 100644
--- a/arch/arm64/include/asm/kvm_hyptrace.h
+++ b/arch/arm64/include/asm/kvm_hyptrace.h
@@ -10,4 +10,17 @@ struct hyp_trace_desc {
struct trace_buffer_desc trace_buffer_desc;
};
+
+struct hyp_event_id {
+ unsigned short id;
+ atomic_t enabled;
+};
+
+extern struct remote_event __hyp_events_start[];
+extern struct remote_event __hyp_events_end[];
+
+/* hyp_event section used by the hypervisor */
+extern struct hyp_event_id __hyp_event_ids_start[];
+extern struct hyp_event_id __hyp_event_ids_end[];
+
#endif
diff --git a/arch/arm64/kernel/image-vars.h b/arch/arm64/kernel/image-vars.h
index d7b0d12b1015..d4c7d45ae6bc 100644
--- a/arch/arm64/kernel/image-vars.h
+++ b/arch/arm64/kernel/image-vars.h
@@ -138,6 +138,10 @@ KVM_NVHE_ALIAS(__hyp_data_start);
KVM_NVHE_ALIAS(__hyp_data_end);
KVM_NVHE_ALIAS(__hyp_rodata_start);
KVM_NVHE_ALIAS(__hyp_rodata_end);
+#ifdef CONFIG_NVHE_EL2_TRACING
+KVM_NVHE_ALIAS(__hyp_event_ids_start);
+KVM_NVHE_ALIAS(__hyp_event_ids_end);
+#endif
/* pKVM static key */
KVM_NVHE_ALIAS(kvm_protected_mode_initialized);
diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S
index ad6133b89e7a..273a461c6076 100644
--- a/arch/arm64/kernel/vmlinux.lds.S
+++ b/arch/arm64/kernel/vmlinux.lds.S
@@ -13,12 +13,23 @@
*(__kvm_ex_table) \
__stop___kvm_ex_table = .;
+#ifdef CONFIG_NVHE_EL2_TRACING
+#define HYPERVISOR_EVENT_IDS \
+ . = ALIGN(PAGE_SIZE); \
+ __hyp_event_ids_start = .; \
+ *(HYP_SECTION_NAME(.event_ids)) \
+ __hyp_event_ids_end = .;
+#else
+#define HYPERVISOR_EVENT_IDS
+#endif
+
#define HYPERVISOR_RODATA_SECTIONS \
HYP_SECTION_NAME(.rodata) : { \
. = ALIGN(PAGE_SIZE); \
__hyp_rodata_start = .; \
*(HYP_SECTION_NAME(.data..ro_after_init)) \
*(HYP_SECTION_NAME(.rodata)) \
+ HYPERVISOR_EVENT_IDS \
. = ALIGN(PAGE_SIZE); \
__hyp_rodata_end = .; \
}
@@ -307,6 +318,13 @@ SECTIONS
HYPERVISOR_DATA_SECTION
+#ifdef CONFIG_NVHE_EL2_TRACING
+ .data.hyp_events : {
+ __hyp_events_start = .;
+ *(SORT(_hyp_events.*))
+ __hyp_events_end = .;
+ }
+#endif
/*
* Data written with the MMU off but read with the MMU on requires
* cache lines to be invalidated, discarding up to a Cache Writeback
diff --git a/arch/arm64/kvm/hyp/include/nvhe/define_events.h b/arch/arm64/kvm/hyp/include/nvhe/define_events.h
new file mode 100644
index 000000000000..776d4c6cb702
--- /dev/null
+++ b/arch/arm64/kvm/hyp/include/nvhe/define_events.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#undef HYP_EVENT
+#define HYP_EVENT(__name, __proto, __struct, __assign, __printk) \
+ struct hyp_event_id hyp_event_id_##__name \
+ __section(".hyp.event_ids."#__name) = { \
+ .enabled = ATOMIC_INIT(0), \
+ }
+
+#define HYP_EVENT_MULTI_READ
+#include <asm/kvm_hypevents.h>
+#undef HYP_EVENT_MULTI_READ
+
+#undef HYP_EVENT
diff --git a/arch/arm64/kvm/hyp/include/nvhe/trace.h b/arch/arm64/kvm/hyp/include/nvhe/trace.h
index 44912869d184..802a18b77c56 100644
--- a/arch/arm64/kvm/hyp/include/nvhe/trace.h
+++ b/arch/arm64/kvm/hyp/include/nvhe/trace.h
@@ -1,9 +1,36 @@
/* SPDX-License-Identifier: GPL-2.0-only */
#ifndef __ARM64_KVM_HYP_NVHE_TRACE_H
#define __ARM64_KVM_HYP_NVHE_TRACE_H
+
+#include <linux/trace_remote_event.h>
+
#include <asm/kvm_hyptrace.h>
+#define HE_PROTO(__args...) __args
+#define HE_ASSIGN(__args...) __args
+#define HE_STRUCT RE_STRUCT
+#define he_field re_field
+
#ifdef CONFIG_NVHE_EL2_TRACING
+
+#define HYP_EVENT(__name, __proto, __struct, __assign, __printk) \
+ REMOTE_EVENT_FORMAT(__name, __struct); \
+ extern struct hyp_event_id hyp_event_id_##__name; \
+ static __always_inline void trace_##__name(__proto) \
+ { \
+ struct remote_event_format_##__name *__entry; \
+ size_t length = sizeof(*__entry); \
+ \
+ if (!atomic_read(&hyp_event_id_##__name.enabled)) \
+ return; \
+ __entry = tracing_reserve_entry(length); \
+ if (!__entry) \
+ return; \
+ __entry->hdr.id = hyp_event_id_##__name.id; \
+ __assign \
+ tracing_commit_entry(); \
+ }
+
void *tracing_reserve_entry(unsigned long length);
void tracing_commit_entry(void);
@@ -13,9 +40,12 @@ int __tracing_enable(bool enable);
int __tracing_swap_reader(unsigned int cpu);
void __tracing_update_clock(u32 mult, u32 shift, u64 epoch_ns, u64 epoch_cyc);
int __tracing_reset(unsigned int cpu);
+int __tracing_enable_event(unsigned short id, bool enable);
#else
static inline void *tracing_reserve_entry(unsigned long length) { return NULL; }
static inline void tracing_commit_entry(void) { }
+#define HYP_EVENT(__name, __proto, __struct, __assign, __printk) \
+ static inline void trace_##__name(__proto) {}
static inline int __tracing_load(unsigned long desc_va, size_t desc_size) { return -ENODEV; }
static inline void __tracing_unload(void) { }
@@ -23,5 +53,6 @@ static inline int __tracing_enable(bool enable) { return -ENODEV; }
static inline int __tracing_swap_reader(unsigned int cpu) { return -ENODEV; }
static inline void __tracing_update_clock(u32 mult, u32 shift, u64 epoch_ns, u64 epoch_cyc) { }
static inline int __tracing_reset(unsigned int cpu) { return -ENODEV; }
+static inline int __tracing_enable_event(unsigned short id, bool enable) { return -ENODEV; }
#endif
#endif
diff --git a/arch/arm64/kvm/hyp/nvhe/Makefile b/arch/arm64/kvm/hyp/nvhe/Makefile
index f1840628d2d6..143d55ec7298 100644
--- a/arch/arm64/kvm/hyp/nvhe/Makefile
+++ b/arch/arm64/kvm/hyp/nvhe/Makefile
@@ -29,7 +29,7 @@ hyp-obj-y += ../vgic-v3-sr.o ../aarch32.o ../vgic-v2-cpuif-proxy.o ../entry.o \
../fpsimd.o ../hyp-entry.o ../exception.o ../pgtable.o
hyp-obj-y += ../../../kernel/smccc-call.o
hyp-obj-$(CONFIG_LIST_HARDENED) += list_debug.o
-hyp-obj-$(CONFIG_NVHE_EL2_TRACING) += clock.o trace.o
+hyp-obj-$(CONFIG_NVHE_EL2_TRACING) += clock.o trace.o events.o
hyp-obj-y += $(lib-objs)
# Path to simple_ring_buffer.c
diff --git a/arch/arm64/kvm/hyp/nvhe/events.c b/arch/arm64/kvm/hyp/nvhe/events.c
new file mode 100644
index 000000000000..add9383aadb5
--- /dev/null
+++ b/arch/arm64/kvm/hyp/nvhe/events.c
@@ -0,0 +1,25 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2025 Google LLC
+ * Author: Vincent Donnefort <vdonnefort@google.com>
+ */
+
+#include <nvhe/mm.h>
+#include <nvhe/trace.h>
+
+#include <nvhe/define_events.h>
+
+int __tracing_enable_event(unsigned short id, bool enable)
+{
+ struct hyp_event_id *event_id = &__hyp_event_ids_start[id];
+ atomic_t *enabled;
+
+ if (event_id >= __hyp_event_ids_end)
+ return -EINVAL;
+
+ enabled = hyp_fixmap_map(__hyp_pa(&event_id->enabled));
+ atomic_set(enabled, enable);
+ hyp_fixmap_unmap();
+
+ return 0;
+}
diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
index 9b05f0c87586..fc5953f31b4b 100644
--- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c
+++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
@@ -632,6 +632,14 @@ static void handle___tracing_reset(struct kvm_cpu_context *host_ctxt)
cpu_reg(host_ctxt, 1) = __tracing_reset(cpu);
}
+static void handle___tracing_enable_event(struct kvm_cpu_context *host_ctxt)
+{
+ DECLARE_REG(unsigned short, id, host_ctxt, 1);
+ DECLARE_REG(bool, enable, host_ctxt, 2);
+
+ cpu_reg(host_ctxt, 1) = __tracing_enable_event(id, enable);
+}
+
typedef void (*hcall_t)(struct kvm_cpu_context *);
#define HANDLE_FUNC(x) [__KVM_HOST_SMCCC_FUNC_##x] = (hcall_t)handle_##x
@@ -679,6 +687,7 @@ static const hcall_t host_hcall[] = {
HANDLE_FUNC(__tracing_swap_reader),
HANDLE_FUNC(__tracing_update_clock),
HANDLE_FUNC(__tracing_reset),
+ HANDLE_FUNC(__tracing_enable_event),
};
static void handle_host_hcall(struct kvm_cpu_context *host_ctxt)
diff --git a/arch/arm64/kvm/hyp/nvhe/hyp.lds.S b/arch/arm64/kvm/hyp/nvhe/hyp.lds.S
index d724f6d69302..7a02837203d1 100644
--- a/arch/arm64/kvm/hyp/nvhe/hyp.lds.S
+++ b/arch/arm64/kvm/hyp/nvhe/hyp.lds.S
@@ -16,6 +16,12 @@ SECTIONS {
HYP_SECTION(.text)
HYP_SECTION(.data..ro_after_init)
HYP_SECTION(.rodata)
+#ifdef CONFIG_NVHE_EL2_TRACING
+ . = ALIGN(PAGE_SIZE);
+ BEGIN_HYP_SECTION(.event_ids)
+ *(SORT(.hyp.event_ids.*))
+ END_HYP_SECTION
+#endif
/*
* .hyp..data..percpu needs to be page aligned to maintain the same
diff --git a/arch/arm64/kvm/hyp_trace.c b/arch/arm64/kvm/hyp_trace.c
index 09bc192e3514..0144cd26703e 100644
--- a/arch/arm64/kvm/hyp_trace.c
+++ b/arch/arm64/kvm/hyp_trace.c
@@ -318,6 +318,25 @@ static int hyp_trace_reset(unsigned int cpu, void *priv)
static int hyp_trace_enable_event(unsigned short id, bool enable, void *priv)
{
+ struct hyp_event_id *event_id = lm_alias(&__hyp_event_ids_start[id]);
+ struct page *page;
+ atomic_t *enabled;
+ void *map;
+
+ if (is_protected_kvm_enabled())
+ return kvm_call_hyp_nvhe(__tracing_enable_event, id, enable);
+
+ enabled = &event_id->enabled;
+ page = virt_to_page(enabled);
+ map = vmap(&page, 1, VM_MAP, PAGE_KERNEL);
+ if (!map)
+ return -ENOMEM;
+
+ enabled = map + offset_in_page(enabled);
+ atomic_set(enabled, enable);
+
+ vunmap(map);
+
return 0;
}
@@ -345,6 +364,19 @@ static struct trace_remote_callbacks trace_remote_callbacks = {
.enable_event = hyp_trace_enable_event,
};
+#include <asm/kvm_define_hypevents.h>
+
+static void __init hyp_trace_init_events(void)
+{
+ struct hyp_event_id *hyp_event_id = __hyp_event_ids_start;
+ struct remote_event *event = __hyp_events_start;
+ int id = 0;
+
+ /* Events on both sides hypervisor are sorted */
+ for (; event < __hyp_events_end; event++, hyp_event_id++, id++)
+ event->id = hyp_event_id->id = id;
+}
+
int __init kvm_hyp_trace_init(void)
{
int cpu;
@@ -364,5 +396,8 @@ int __init kvm_hyp_trace_init(void)
}
#endif
- return trace_remote_register("hypervisor", &trace_remote_callbacks, &trace_buffer, NULL, 0);
+ hyp_trace_init_events();
+
+ return trace_remote_register("hypervisor", &trace_remote_callbacks, &trace_buffer,
+ __hyp_events_start, __hyp_events_end - __hyp_events_start);
}
--
2.53.0.473.g4a7958ca14-goog
^ permalink raw reply related
page: next (older) | prev (newer) | latest
- recent:[subjects (threaded)|topics (new)|topics (active)]
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox