This commit adds an rcutorture.reader_flavor parameter whose bits
correspond to reader flavors. For example, SRCU's readers are 0x1 for
normal and 0x2 for NMI-safe.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: <bpf@vger.kernel.org>
---
.../admin-guide/kernel-parameters.txt | 8 +++++
kernel/rcu/rcutorture.c | 30 ++++++++++++++-----
2 files changed, 30 insertions(+), 8 deletions(-)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 1518343bbe223..52922727006fc 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -5426,6 +5426,14 @@
The delay, in seconds, between successive
read-then-exit testing episodes.
+ rcutorture.reader_flavor= [KNL]
+ A bit mask indicating which readers to use.
+ If there is more than one bit set, the readers
+ are entered from low-order bit up, and are
+ exited in the opposite order. For SRCU, the
+ 0x1 bit is normal readers and the 0x2 bit is
+ for NMI-safe readers.
+
rcutorture.shuffle_interval= [KNL]
Set task-shuffle interval (s). Shuffling tasks
allows some CPUs to go into dyntick-idle mode
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index f96ab98f8182f..405decec33677 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -111,6 +111,7 @@ torture_param(int, nocbs_nthreads, 0, "Number of NOCB toggle threads, 0 to disab
torture_param(int, nocbs_toggle, 1000, "Time between toggling nocb state (ms)");
torture_param(int, read_exit_delay, 13, "Delay between read-then-exit episodes (s)");
torture_param(int, read_exit_burst, 16, "# of read-then-exit bursts per episode, zero to disable");
+torture_param(int, reader_flavor, 0x1, "Reader flavors to use, one per bit.");
torture_param(int, shuffle_interval, 3, "Number of seconds between shuffles");
torture_param(int, shutdown_secs, 0, "Shutdown time (s), <= zero to disable.");
torture_param(int, stall_cpu, 0, "Stall duration (s), zero to disable.");
@@ -644,10 +645,20 @@ static void srcu_get_gp_data(int *flags, unsigned long *gp_seq)
static int srcu_torture_read_lock(void)
{
- if (cur_ops == &srcud_ops)
- return srcu_read_lock_nmisafe(srcu_ctlp);
- else
- return srcu_read_lock(srcu_ctlp);
+ int idx;
+ int ret = 0;
+
+ if ((reader_flavor & 0x1) || !(reader_flavor & 0x7)) {
+ idx = srcu_read_lock(srcu_ctlp);
+ WARN_ON_ONCE(idx & ~0x1);
+ ret += idx;
+ }
+ if (reader_flavor & 0x2) {
+ idx = srcu_read_lock_nmisafe(srcu_ctlp);
+ WARN_ON_ONCE(idx & ~0x1);
+ ret += idx << 1;
+ }
+ return ret;
}
static void
@@ -671,10 +682,11 @@ srcu_read_delay(struct torture_random_state *rrsp, struct rt_read_seg *rtrsp)
static void srcu_torture_read_unlock(int idx)
{
- if (cur_ops == &srcud_ops)
- srcu_read_unlock_nmisafe(srcu_ctlp, idx);
- else
- srcu_read_unlock(srcu_ctlp, idx);
+ WARN_ON_ONCE((reader_flavor && (idx & ~reader_flavor)) || (!reader_flavor && (idx & ~0x1)));
+ if (reader_flavor & 0x2)
+ srcu_read_unlock_nmisafe(srcu_ctlp, (idx & 0x2) >> 1);
+ if ((reader_flavor & 0x1) || !(reader_flavor & 0x7))
+ srcu_read_unlock(srcu_ctlp, idx & 0x1);
}
static int torture_srcu_read_lock_held(void)
@@ -2389,6 +2401,7 @@ rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, const char *tag)
"n_barrier_cbs=%d "
"onoff_interval=%d onoff_holdoff=%d "
"read_exit_delay=%d read_exit_burst=%d "
+ "reader_flavor=%x "
"nocbs_nthreads=%d nocbs_toggle=%d "
"test_nmis=%d\n",
torture_type, tag, nrealreaders, nfakewriters,
@@ -2401,6 +2414,7 @@ rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, const char *tag)
n_barrier_cbs,
onoff_interval, onoff_holdoff,
read_exit_delay, read_exit_burst,
+ reader_flavor,
nocbs_nthreads, nocbs_toggle,
test_nmis);
}
--
2.40.1On 10/15/2024 9:41 PM, Paul E. McKenney wrote:
> This commit adds an rcutorture.reader_flavor parameter whose bits
> correspond to reader flavors. For example, SRCU's readers are 0x1 for
> normal and 0x2 for NMI-safe.
>
> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
> Cc: Alexei Starovoitov <ast@kernel.org>
> Cc: Andrii Nakryiko <andrii@kernel.org>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Kent Overstreet <kent.overstreet@linux.dev>
> Cc: <bpf@vger.kernel.org>
> ---
> .../admin-guide/kernel-parameters.txt | 8 +++++
> kernel/rcu/rcutorture.c | 30 ++++++++++++++-----
> 2 files changed, 30 insertions(+), 8 deletions(-)
>
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index 1518343bbe223..52922727006fc 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -5426,6 +5426,14 @@
> The delay, in seconds, between successive
> read-then-exit testing episodes.
>
> + rcutorture.reader_flavor= [KNL]
> + A bit mask indicating which readers to use.
> + If there is more than one bit set, the readers
> + are entered from low-order bit up, and are
> + exited in the opposite order. For SRCU, the
> + 0x1 bit is normal readers and the 0x2 bit is
> + for NMI-safe readers.
> +
> rcutorture.shuffle_interval= [KNL]
> Set task-shuffle interval (s). Shuffling tasks
> allows some CPUs to go into dyntick-idle mode
> diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
> index f96ab98f8182f..405decec33677 100644
> --- a/kernel/rcu/rcutorture.c
> +++ b/kernel/rcu/rcutorture.c
> @@ -111,6 +111,7 @@ torture_param(int, nocbs_nthreads, 0, "Number of NOCB toggle threads, 0 to disab
> torture_param(int, nocbs_toggle, 1000, "Time between toggling nocb state (ms)");
> torture_param(int, read_exit_delay, 13, "Delay between read-then-exit episodes (s)");
> torture_param(int, read_exit_burst, 16, "# of read-then-exit bursts per episode, zero to disable");
> +torture_param(int, reader_flavor, 0x1, "Reader flavors to use, one per bit.");
> torture_param(int, shuffle_interval, 3, "Number of seconds between shuffles");
> torture_param(int, shutdown_secs, 0, "Shutdown time (s), <= zero to disable.");
> torture_param(int, stall_cpu, 0, "Stall duration (s), zero to disable.");
> @@ -644,10 +645,20 @@ static void srcu_get_gp_data(int *flags, unsigned long *gp_seq)
>
> static int srcu_torture_read_lock(void)
> {
> - if (cur_ops == &srcud_ops)
> - return srcu_read_lock_nmisafe(srcu_ctlp);
> - else
> - return srcu_read_lock(srcu_ctlp);
> + int idx;
> + int ret = 0;
> +
> + if ((reader_flavor & 0x1) || !(reader_flavor & 0x7)) {
Minor: Maybe use macros in place of 0x1, 0x2, 0x7 as a cleanup later.
- Neeraj
> + idx = srcu_read_lock(srcu_ctlp);
> + WARN_ON_ONCE(idx & ~0x1);
> + ret += idx;
> + }
> + if (reader_flavor & 0x2) {
> + idx = srcu_read_lock_nmisafe(srcu_ctlp);
> + WARN_ON_ONCE(idx & ~0x1);
> + ret += idx << 1;
> + }
> + return ret;
> }
>
On Tue, Nov 12, 2024 at 10:12:40AM +0530, Neeraj Upadhyay wrote:
> On 10/15/2024 9:41 PM, Paul E. McKenney wrote:
> > This commit adds an rcutorture.reader_flavor parameter whose bits
> > correspond to reader flavors. For example, SRCU's readers are 0x1 for
> > normal and 0x2 for NMI-safe.
> >
> > Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
> > Cc: Alexei Starovoitov <ast@kernel.org>
> > Cc: Andrii Nakryiko <andrii@kernel.org>
> > Cc: Peter Zijlstra <peterz@infradead.org>
> > Cc: Kent Overstreet <kent.overstreet@linux.dev>
> > Cc: <bpf@vger.kernel.org>
> > ---
> > .../admin-guide/kernel-parameters.txt | 8 +++++
> > kernel/rcu/rcutorture.c | 30 ++++++++++++++-----
> > 2 files changed, 30 insertions(+), 8 deletions(-)
> >
> > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> > index 1518343bbe223..52922727006fc 100644
> > --- a/Documentation/admin-guide/kernel-parameters.txt
> > +++ b/Documentation/admin-guide/kernel-parameters.txt
> > @@ -5426,6 +5426,14 @@
> > The delay, in seconds, between successive
> > read-then-exit testing episodes.
> >
> > + rcutorture.reader_flavor= [KNL]
> > + A bit mask indicating which readers to use.
> > + If there is more than one bit set, the readers
> > + are entered from low-order bit up, and are
> > + exited in the opposite order. For SRCU, the
> > + 0x1 bit is normal readers and the 0x2 bit is
> > + for NMI-safe readers.
> > +
> > rcutorture.shuffle_interval= [KNL]
> > Set task-shuffle interval (s). Shuffling tasks
> > allows some CPUs to go into dyntick-idle mode
> > diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
> > index f96ab98f8182f..405decec33677 100644
> > --- a/kernel/rcu/rcutorture.c
> > +++ b/kernel/rcu/rcutorture.c
> > @@ -111,6 +111,7 @@ torture_param(int, nocbs_nthreads, 0, "Number of NOCB toggle threads, 0 to disab
> > torture_param(int, nocbs_toggle, 1000, "Time between toggling nocb state (ms)");
> > torture_param(int, read_exit_delay, 13, "Delay between read-then-exit episodes (s)");
> > torture_param(int, read_exit_burst, 16, "# of read-then-exit bursts per episode, zero to disable");
> > +torture_param(int, reader_flavor, 0x1, "Reader flavors to use, one per bit.");
> > torture_param(int, shuffle_interval, 3, "Number of seconds between shuffles");
> > torture_param(int, shutdown_secs, 0, "Shutdown time (s), <= zero to disable.");
> > torture_param(int, stall_cpu, 0, "Stall duration (s), zero to disable.");
> > @@ -644,10 +645,20 @@ static void srcu_get_gp_data(int *flags, unsigned long *gp_seq)
> >
> > static int srcu_torture_read_lock(void)
> > {
> > - if (cur_ops == &srcud_ops)
> > - return srcu_read_lock_nmisafe(srcu_ctlp);
> > - else
> > - return srcu_read_lock(srcu_ctlp);
> > + int idx;
> > + int ret = 0;
> > +
> > + if ((reader_flavor & 0x1) || !(reader_flavor & 0x7)) {
>
> Minor: Maybe use macros in place of 0x1, 0x2, 0x7 as a cleanup later.
Hmmm...
I could move SRCU_READ_FLAVOR_* to include/linux/srcu.h and make
rcutorture use those. Plus have a combined mask for the instances of 0x7.
Or is there a better way?
Thanx, Paul
> - Neeraj
>
> > + idx = srcu_read_lock(srcu_ctlp);
> > + WARN_ON_ONCE(idx & ~0x1);
> > + ret += idx;
> > + }
> > + if (reader_flavor & 0x2) {
> > + idx = srcu_read_lock_nmisafe(srcu_ctlp);
> > + WARN_ON_ONCE(idx & ~0x1);
> > + ret += idx << 1;
> > + }
> > + return ret;
> > }
> >
>
>>>
>>> static int srcu_torture_read_lock(void)
>>> {
>>> - if (cur_ops == &srcud_ops)
>>> - return srcu_read_lock_nmisafe(srcu_ctlp);
>>> - else
>>> - return srcu_read_lock(srcu_ctlp);
>>> + int idx;
>>> + int ret = 0;
>>> +
>>> + if ((reader_flavor & 0x1) || !(reader_flavor & 0x7)) {
>>
>> Minor: Maybe use macros in place of 0x1, 0x2, 0x7 as a cleanup later.
>
> Hmmm...
>
> I could move SRCU_READ_FLAVOR_* to include/linux/srcu.h and make
> rcutorture use those. Plus have a combined mask for the instances of 0x7.
>
> Or is there a better way?
>
Yes, I was thinking the same. This looks good.
- Neeraj
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