Single-argument kvfree_rcu() usage is being deprecated [1] [2] as it is
error-prone. However, till all users are converted, we would like to introduce
checkpatch errors for new patches submitted.
This patch adds support for the same. Tested with a trial patch.
For now, we are only considering usages that don't have compound
nesting, for example ignore: kvfree_rcu( (rcu_head_obj), rcu_head_name).
This is sufficient as such usages are unlikely.
Once all users are converted and we remove the old API, we can also revert this
checkpatch patch then.
[1] https://lore.kernel.org/rcu/CAEXW_YRhHaVuq+5f+VgCZM=SF+9xO+QXaxe0yE7oA9iCXK-XPg@mail.gmail.com/
[2] https://lore.kernel.org/rcu/CAEXW_YSY=q2_uaE2qo4XSGjzs4+C102YMVJ7kWwuT5LGmJGGew@mail.gmail.com/
Signed-off-by: Joel Fernandes (Google) <[email protected]>
---
scripts/checkpatch.pl | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index bd44d12965c9..9da0a3cb1615 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -6388,6 +6388,15 @@ sub process {
}
}
+# check for soon-to-be-deprecated single-argument k[v]free_rcu() API
+ if ($line =~ /\bk[v]?free_rcu\s*\([^(]+\)/) {
+ if ($line =~ /\bk[v]?free_rcu\s*\([^,]+\)/) {
+ ERROR("DEPRECATED_API",
+ "Single-argument k[v]free_rcu() API is deprecated, please call the API with an rcu_head object passed, like: k[v]free_rcu(object_ptr, rcu_head_name); " . $herecurr);
+ }
+ }
+
+
# check for unnecessary "Out of Memory" messages
if ($line =~ /^\+.*\b$logFunctions\s*\(/ &&
$prevline =~ /^[ \+]\s*if\s*\(\s*(\!\s*|NULL\s*==\s*)?($Lval)(\s*==\s*NULL\s*)?\s*\)/ &&
--
2.40.0.rc0.216.gc4246ad0f0-goog
On Mon, Mar 6, 2023 at 10:08 PM Joe Perches <[email protected]> wrote:
>
> On Tue, 2023-03-07 at 03:04 +0000, Joel Fernandes (Google) wrote:
> > Single-argument kvfree_rcu() usage is being deprecated [1] [2] as it is
> > error-prone. However, till all users are converted, we would like to introduce
> > checkpatch errors for new patches submitted.
> >
> > This patch adds support for the same. Tested with a trial patch.
> >
> > For now, we are only considering usages that don't have compound
> > nesting, for example ignore: kvfree_rcu( (rcu_head_obj), rcu_head_name).
> > This is sufficient as such usages are unlikely.
> >
> > Once all users are converted and we remove the old API, we can also revert this
> > checkpatch patch then.
>
> I think this should be added to the deprecated_apis hash instead
>
> our %deprecated_apis = (
> "synchronize_rcu_bh" => "synchronize_rcu",
> "synchronize_rcu_bh_expedited" => "synchronize_rcu_expedited",
> "call_rcu_bh" => "call_rcu",
> "rcu_barrier_bh" => "rcu_barrier",
> "synchronize_sched" => "synchronize_rcu",
> "synchronize_sched_expedited" => "synchronize_rcu_expedited",
> "call_rcu_sched" => "call_rcu",
> "rcu_barrier_sched" => "rcu_barrier",
> "get_state_synchronize_sched" => "get_state_synchronize_rcu",
> "cond_synchronize_sched" => "cond_synchronize_rcu",
> "kmap" => "kmap_local_page",
> "kunmap" => "kunmap_local",
> "kmap_atomic" => "kmap_local_page",
> "kunmap_atomic" => "kunmap_local",
> );
This is not an API name change though, it is a "number of arguments"
or argument list change. Is there a different way to do it?
thanks,
- Joel
On Mon, 2023-03-06 at 22:10 -0500, Joel Fernandes wrote:
> On Mon, Mar 6, 2023 at 10:08 PM Joe Perches <[email protected]> wrote:
> >
> > On Tue, 2023-03-07 at 03:04 +0000, Joel Fernandes (Google) wrote:
> > > Single-argument kvfree_rcu() usage is being deprecated [1] [2] as it is
> > > error-prone. However, till all users are converted, we would like to introduce
> > > checkpatch errors for new patches submitted.
> > >
> > > This patch adds support for the same. Tested with a trial patch.
> > >
> > > For now, we are only considering usages that don't have compound
> > > nesting, for example ignore: kvfree_rcu( (rcu_head_obj), rcu_head_name).
> > > This is sufficient as such usages are unlikely.
> > >
> > > Once all users are converted and we remove the old API, we can also revert this
> > > checkpatch patch then.
> >
> > I think this should be added to the deprecated_apis hash instead
> >
> > our %deprecated_apis = (
> > "synchronize_rcu_bh" => "synchronize_rcu",
> > "synchronize_rcu_bh_expedited" => "synchronize_rcu_expedited",
> > "call_rcu_bh" => "call_rcu",
> > "rcu_barrier_bh" => "rcu_barrier",
> > "synchronize_sched" => "synchronize_rcu",
> > "synchronize_sched_expedited" => "synchronize_rcu_expedited",
> > "call_rcu_sched" => "call_rcu",
> > "rcu_barrier_sched" => "rcu_barrier",
> > "get_state_synchronize_sched" => "get_state_synchronize_rcu",
> > "cond_synchronize_sched" => "cond_synchronize_rcu",
> > "kmap" => "kmap_local_page",
> > "kunmap" => "kunmap_local",
> > "kmap_atomic" => "kmap_local_page",
> > "kunmap_atomic" => "kunmap_local",
> > );
>
> This is not an API name change though, it is a "number of arguments"
> or argument list change. Is there a different way to do it?
Ah, no, not really.
btw: I don't see a single use of this call without a comma in the tree.
On Tue, 2023-03-07 at 03:04 +0000, Joel Fernandes (Google) wrote:
> Single-argument kvfree_rcu() usage is being deprecated [1] [2] as it is
> error-prone. However, till all users are converted, we would like to introduce
> checkpatch errors for new patches submitted.
>
> This patch adds support for the same. Tested with a trial patch.
>
> For now, we are only considering usages that don't have compound
> nesting, for example ignore: kvfree_rcu( (rcu_head_obj), rcu_head_name).
> This is sufficient as such usages are unlikely.
>
> Once all users are converted and we remove the old API, we can also revert this
> checkpatch patch then.
I think this should be added to the deprecated_apis hash instead
our %deprecated_apis = (
"synchronize_rcu_bh" => "synchronize_rcu",
"synchronize_rcu_bh_expedited" => "synchronize_rcu_expedited",
"call_rcu_bh" => "call_rcu",
"rcu_barrier_bh" => "rcu_barrier",
"synchronize_sched" => "synchronize_rcu",
"synchronize_sched_expedited" => "synchronize_rcu_expedited",
"call_rcu_sched" => "call_rcu",
"rcu_barrier_sched" => "rcu_barrier",
"get_state_synchronize_sched" => "get_state_synchronize_rcu",
"cond_synchronize_sched" => "cond_synchronize_rcu",
"kmap" => "kmap_local_page",
"kunmap" => "kunmap_local",
"kmap_atomic" => "kmap_local_page",
"kunmap_atomic" => "kunmap_local",
);
On Mon, Mar 06, 2023 at 07:23:23PM -0800, Joe Perches wrote:
> On Mon, 2023-03-06 at 22:10 -0500, Joel Fernandes wrote:
> > On Mon, Mar 6, 2023 at 10:08 PM Joe Perches <[email protected]> wrote:
> > >
> > > On Tue, 2023-03-07 at 03:04 +0000, Joel Fernandes (Google) wrote:
> > > > Single-argument kvfree_rcu() usage is being deprecated [1] [2] as it is
> > > > error-prone. However, till all users are converted, we would like to introduce
> > > > checkpatch errors for new patches submitted.
> > > >
> > > > This patch adds support for the same. Tested with a trial patch.
> > > >
> > > > For now, we are only considering usages that don't have compound
> > > > nesting, for example ignore: kvfree_rcu( (rcu_head_obj), rcu_head_name).
> > > > This is sufficient as such usages are unlikely.
> > > >
> > > > Once all users are converted and we remove the old API, we can also revert this
> > > > checkpatch patch then.
> > >
> > > I think this should be added to the deprecated_apis hash instead
> > >
> > > our %deprecated_apis = (
> > > "synchronize_rcu_bh" => "synchronize_rcu",
> > > "synchronize_rcu_bh_expedited" => "synchronize_rcu_expedited",
> > > "call_rcu_bh" => "call_rcu",
> > > "rcu_barrier_bh" => "rcu_barrier",
> > > "synchronize_sched" => "synchronize_rcu",
> > > "synchronize_sched_expedited" => "synchronize_rcu_expedited",
> > > "call_rcu_sched" => "call_rcu",
> > > "rcu_barrier_sched" => "rcu_barrier",
> > > "get_state_synchronize_sched" => "get_state_synchronize_rcu",
> > > "cond_synchronize_sched" => "cond_synchronize_rcu",
> > > "kmap" => "kmap_local_page",
> > > "kunmap" => "kunmap_local",
> > > "kmap_atomic" => "kmap_local_page",
> > > "kunmap_atomic" => "kunmap_local",
> > > );
> >
> > This is not an API name change though, it is a "number of arguments"
> > or argument list change. Is there a different way to do it?
>
> Ah, no, not really.
>
> btw: I don't see a single use of this call without a comma in the tree.
>
Did you look for kvfree_rcu? It is either kvfree_rcu() or kfree_rcu().
thanks,
- Joel
On Tue, 2023-03-07 at 04:41 +0000, Joel Fernandes wrote:
> On Mon, Mar 06, 2023 at 07:23:23PM -0800, Joe Perches wrote:
> > On Mon, 2023-03-06 at 22:10 -0500, Joel Fernandes wrote:
> > > On Mon, Mar 6, 2023 at 10:08 PM Joe Perches <[email protected]> wrote:
> > > >
> > > > On Tue, 2023-03-07 at 03:04 +0000, Joel Fernandes (Google) wrote:
> > > > > Single-argument kvfree_rcu() usage is being deprecated [1] [2] as it is
> > > > > error-prone. However, till all users are converted, we would like to introduce
> > > > > checkpatch errors for new patches submitted.
> > > > >
> > > > > This patch adds support for the same. Tested with a trial patch.
> > > > >
> > > > > For now, we are only considering usages that don't have compound
> > > > > nesting, for example ignore: kvfree_rcu( (rcu_head_obj), rcu_head_name).
> > > > > This is sufficient as such usages are unlikely.
> > > > >
> > > > > Once all users are converted and we remove the old API, we can also revert this
> > > > > checkpatch patch then.
> > > >
> > > > I think this should be added to the deprecated_apis hash instead
> > > >
> > > > our %deprecated_apis = (
> > > > "synchronize_rcu_bh" => "synchronize_rcu",
> > > > "synchronize_rcu_bh_expedited" => "synchronize_rcu_expedited",
> > > > "call_rcu_bh" => "call_rcu",
> > > > "rcu_barrier_bh" => "rcu_barrier",
> > > > "synchronize_sched" => "synchronize_rcu",
> > > > "synchronize_sched_expedited" => "synchronize_rcu_expedited",
> > > > "call_rcu_sched" => "call_rcu",
> > > > "rcu_barrier_sched" => "rcu_barrier",
> > > > "get_state_synchronize_sched" => "get_state_synchronize_rcu",
> > > > "cond_synchronize_sched" => "cond_synchronize_rcu",
> > > > "kmap" => "kmap_local_page",
> > > > "kunmap" => "kunmap_local",
> > > > "kmap_atomic" => "kmap_local_page",
> > > > "kunmap_atomic" => "kunmap_local",
> > > > );
> > >
> > > This is not an API name change though, it is a "number of arguments"
> > > or argument list change. Is there a different way to do it?
> >
> > Ah, no, not really.
> >
> > btw: I don't see a single use of this call without a comma in the tree.
>
> Did you look for kvfree_rcu? It is either kvfree_rcu() or kfree_rcu().
$ git grep -P '\bkv?free_rcu\s*\(' -- '*.[ch]' | grep -v -P 'kv?free_rcu\s*\([^,]+,.*\)'
drivers/infiniband/core/device.c: kfree_rcu(container_of(dev->port_data, struct ib_port_data_rcu,
drivers/infiniband/core/rdma_core.c: * kfree_rcu(). However the object may still have been released and
drivers/target/target_core_configfs.c: * callbacks to complete post kfree_rcu(), before allowing
include/linux/rcupdate.h: * kvfree_rcu(ptr);
include/linux/rcupdate.h:#define kvfree_rcu(...) KVFREE_GET_MACRO(__VA_ARGS__, \
include/linux/rcutiny.h: // kvfree_rcu(one_arg) call.
include/rdma/ib_verbs.h: struct rcu_head rcu; /* kfree_rcu() overhead */
include/scsi/scsi_device.h: * @rcu: For kfree_rcu().
kernel/rcu/rcuscale.c: pr_alert("CONFIG_RCU_LAZY is disabled, falling back to kfree_rcu() for delayed RCU kfree'ing\n");
kernel/rcu/tree.c: * struct kvfree_rcu_bulk_data - single block to store kvfree_rcu() pointers
kernel/rcu/tree.c: * @records: Array of the kvfree_rcu() pointers
kernel/rcu/tree.c: * struct kfree_rcu_cpu_work - single batch of kfree_rcu() requests
kernel/rcu/tree.c: * @head_free: List of kfree_rcu() objects waiting for a grace period
kernel/rcu/tree.c: * @bulk_head_free: Bulk-List of kvfree_rcu() objects waiting for a grace period
kernel/rcu/tree.c: * struct kfree_rcu_cpu - batch up kfree_rcu() requests for RCU grace period
kernel/rcu/tree.c: * @head: List of kfree_rcu() objects not yet waiting for a grace period
kernel/rcu/tree.c: * @bulk_head: Bulk-List of kvfree_rcu() objects not yet waiting for a grace period
kernel/rcu/tree.c: * @krw_arr: Array of batches of kfree_rcu() objects waiting for a grace period
kernel/rcu/tree.c: * double-argument of kvfree_rcu(). This happens when the
kernel/rcu/tree.c: * reduce the number of grace periods during heavy kfree_rcu()/kvfree_rcu() load.
kernel/rcu/tree.c: // Probable double kfree_rcu(), just leak.
net/core/pktgen.c: /* Don't need rcu_barrier() due to use of kfree_rcu() */
On Mon, Mar 6, 2023 at 11:53 PM Joe Perches <[email protected]> wrote:
>
> On Tue, 2023-03-07 at 04:41 +0000, Joel Fernandes wrote:
> > On Mon, Mar 06, 2023 at 07:23:23PM -0800, Joe Perches wrote:
> > > On Mon, 2023-03-06 at 22:10 -0500, Joel Fernandes wrote:
> > > > On Mon, Mar 6, 2023 at 10:08 PM Joe Perches <[email protected]> wrote:
> > > > >
> > > > > On Tue, 2023-03-07 at 03:04 +0000, Joel Fernandes (Google) wrote:
> > > > > > Single-argument kvfree_rcu() usage is being deprecated [1] [2] as it is
> > > > > > error-prone. However, till all users are converted, we would like to introduce
> > > > > > checkpatch errors for new patches submitted.
> > > > > >
> > > > > > This patch adds support for the same. Tested with a trial patch.
> > > > > >
> > > > > > For now, we are only considering usages that don't have compound
> > > > > > nesting, for example ignore: kvfree_rcu( (rcu_head_obj), rcu_head_name).
> > > > > > This is sufficient as such usages are unlikely.
> > > > > >
> > > > > > Once all users are converted and we remove the old API, we can also revert this
> > > > > > checkpatch patch then.
> > > > >
> > > > > I think this should be added to the deprecated_apis hash instead
> > > > >
> > > > > our %deprecated_apis = (
> > > > > "synchronize_rcu_bh" => "synchronize_rcu",
> > > > > "synchronize_rcu_bh_expedited" => "synchronize_rcu_expedited",
> > > > > "call_rcu_bh" => "call_rcu",
> > > > > "rcu_barrier_bh" => "rcu_barrier",
> > > > > "synchronize_sched" => "synchronize_rcu",
> > > > > "synchronize_sched_expedited" => "synchronize_rcu_expedited",
> > > > > "call_rcu_sched" => "call_rcu",
> > > > > "rcu_barrier_sched" => "rcu_barrier",
> > > > > "get_state_synchronize_sched" => "get_state_synchronize_rcu",
> > > > > "cond_synchronize_sched" => "cond_synchronize_rcu",
> > > > > "kmap" => "kmap_local_page",
> > > > > "kunmap" => "kunmap_local",
> > > > > "kmap_atomic" => "kmap_local_page",
> > > > > "kunmap_atomic" => "kunmap_local",
> > > > > );
> > > >
> > > > This is not an API name change though, it is a "number of arguments"
> > > > or argument list change. Is there a different way to do it?
> > >
> > > Ah, no, not really.
> > >
> > > btw: I don't see a single use of this call without a comma in the tree.
> >
> > Did you look for kvfree_rcu? It is either kvfree_rcu() or kfree_rcu().
>
> $ git grep -P '\bkv?free_rcu\s*\(' -- '*.[ch]' | grep -v -P 'kv?free_rcu\s*\([^,]+,.*\)'
> drivers/infiniband/core/device.c: kfree_rcu(container_of(dev->port_data, struct ib_port_data_rcu,
> drivers/infiniband/core/rdma_core.c: * kfree_rcu(). However the object may still have been released and
> drivers/target/target_core_configfs.c: * callbacks to complete post kfree_rcu(), before allowing
> include/linux/rcupdate.h: * kvfree_rcu(ptr);
> include/linux/rcupdate.h:#define kvfree_rcu(...) KVFREE_GET_MACRO(__VA_ARGS__, \
> include/linux/rcutiny.h: // kvfree_rcu(one_arg) call.
> include/rdma/ib_verbs.h: struct rcu_head rcu; /* kfree_rcu() overhead */
> include/scsi/scsi_device.h: * @rcu: For kfree_rcu().
> kernel/rcu/rcuscale.c: pr_alert("CONFIG_RCU_LAZY is disabled, falling back to kfree_rcu() for delayed RCU kfree'ing\n");
> kernel/rcu/tree.c: * struct kvfree_rcu_bulk_data - single block to store kvfree_rcu() pointers
> kernel/rcu/tree.c: * @records: Array of the kvfree_rcu() pointers
> kernel/rcu/tree.c: * struct kfree_rcu_cpu_work - single batch of kfree_rcu() requests
> kernel/rcu/tree.c: * @head_free: List of kfree_rcu() objects waiting for a grace period
> kernel/rcu/tree.c: * @bulk_head_free: Bulk-List of kvfree_rcu() objects waiting for a grace period
> kernel/rcu/tree.c: * struct kfree_rcu_cpu - batch up kfree_rcu() requests for RCU grace period
> kernel/rcu/tree.c: * @head: List of kfree_rcu() objects not yet waiting for a grace period
> kernel/rcu/tree.c: * @bulk_head: Bulk-List of kvfree_rcu() objects not yet waiting for a grace period
> kernel/rcu/tree.c: * @krw_arr: Array of batches of kfree_rcu() objects waiting for a grace period
> kernel/rcu/tree.c: * double-argument of kvfree_rcu(). This happens when the
> kernel/rcu/tree.c: * reduce the number of grace periods during heavy kfree_rcu()/kvfree_rcu() load.
> kernel/rcu/tree.c: // Probable double kfree_rcu(), just leak.
> net/core/pktgen.c: /* Don't need rcu_barrier() due to use of kfree_rcu() */
>
Do you mind sharing which tree you are looking at? I checked both
6.3-rc1 and linux-next.
Your grep returned:
kernel/trace/trace_osnoise.c: kvfree_rcu(inst);
kernel/trace/trace_probe.c: kvfree_rcu(link);
lib/test_vmalloc.c: kvfree_rcu(p);
mm/list_lru.c: * We need kvfree_rcu() here. And the walking of the list
net/core/pktgen.c: /* Don't need rcu_barrier() due to use of kfree_rcu() */
net/core/sysctl_net_core.c:
kvfree_rcu(orig_sock_table);
net/core/sysctl_net_core.c: kfree_rcu(cur);
net/mac802154/scan.c: kfree_rcu(request);
net/mac802154/scan.c: kfree_rcu(request);
On Tue, 2023-03-07 at 00:11 -0500, Joel Fernandes wrote:
> Do you mind sharing which tree you are looking at? I checked both
> 6.3-rc1 and linux-next.
>
> Your grep returned:
>
> kernel/trace/trace_osnoise.c: kvfree_rcu(inst);
> kernel/trace/trace_probe.c: kvfree_rcu(link);
> lib/test_vmalloc.c: kvfree_rcu(p);
> mm/list_lru.c: * We need kvfree_rcu() here. And the walking of the list
> net/core/pktgen.c: /* Don't need rcu_barrier() due to use of kfree_rcu() */
> net/core/sysctl_net_core.c:
> kvfree_rcu(orig_sock_table);
> net/core/sysctl_net_core.c: kfree_rcu(cur);
> net/mac802154/scan.c: kfree_rcu(request);
> net/mac802154/scan.c: kfree_rcu(request);
rather old. I'm not subscribed and haven't been following much.
Add linux-next specific files for 20230217
Updating to today's next:
Add linux-next specific files for 20230307
I get several instances:
$ git grep -P '\bkv?free_rcu\s*\(' -- '*.[ch]' | grep -v -P 'kv?free_rcu\s*\([^,]+,.*\)'
drivers/block/drbd/drbd_nl.c: kvfree_rcu(old_disk_conf);
drivers/block/drbd/drbd_nl.c: kvfree_rcu(old_net_conf);
drivers/block/drbd/drbd_nl.c: kvfree_rcu(old_disk_conf);
drivers/block/drbd/drbd_receiver.c: kvfree_rcu(old_net_conf);
drivers/block/drbd/drbd_receiver.c: kvfree_rcu(old_disk_conf);
drivers/block/drbd/drbd_state.c: kvfree_rcu(old_conf);
drivers/infiniband/core/device.c: kfree_rcu(container_of(dev->port_data, struct ib_port_data_rcu,
drivers/infiniband/core/rdma_core.c: * kfree_rcu(). However the object may still have been released and
drivers/infiniband/sw/rxe/rxe_mr.c: kfree_rcu(mr);
drivers/misc/vmw_vmci/vmci_context.c: kvfree_rcu(notifier);
drivers/misc/vmw_vmci/vmci_event.c: kvfree_rcu(s);
drivers/net/ethernet/mellanox/mlx5/core/en/tc/int_port.c: kfree_rcu(int_port);
drivers/net/ethernet/mellanox/mlx5/core/en_accel/macsec.c: kfree_rcu(tx_sa);
drivers/net/ethernet/mellanox/mlx5/core/en_accel/macsec.c: kfree_rcu(rx_sc);
drivers/target/target_core_configfs.c: * callbacks to complete post kfree_rcu(), before allowing
fs/ext4/super.c: kfree_rcu(qname);
include/linux/rcupdate.h: * kvfree_rcu(ptr);
include/linux/rcupdate.h:#define kvfree_rcu(...) KVFREE_GET_MACRO(__VA_ARGS__, \
include/linux/rcutiny.h: // kvfree_rcu(one_arg) call.
include/rdma/ib_verbs.h: struct rcu_head rcu; /* kfree_rcu() overhead */
include/scsi/scsi_device.h: * @rcu: For kfree_rcu().
kernel/rcu/rcuscale.c: pr_alert("CONFIG_RCU_LAZY is disabled, falling back to kfree_rcu() for delayed RCU kfree'ing\n");
kernel/rcu/tree.c: * struct kvfree_rcu_bulk_data - single block to store kvfree_rcu() pointers
kernel/rcu/tree.c: * @records: Array of the kvfree_rcu() pointers
kernel/rcu/tree.c: * struct kfree_rcu_cpu_work - single batch of kfree_rcu() requests
kernel/rcu/tree.c: * @head_free: List of kfree_rcu() objects waiting for a grace period
kernel/rcu/tree.c: * @bulk_head_free: Bulk-List of kvfree_rcu() objects waiting for a grace period
kernel/rcu/tree.c: * struct kfree_rcu_cpu - batch up kfree_rcu() requests for RCU grace period
kernel/rcu/tree.c: * @head: List of kfree_rcu() objects not yet waiting for a grace period
kernel/rcu/tree.c: * @bulk_head: Bulk-List of kvfree_rcu() objects not yet waiting for a grace period
kernel/rcu/tree.c: * @krw_arr: Array of batches of kfree_rcu() objects waiting for a grace period
kernel/rcu/tree.c: * double-argument of kvfree_rcu(). This happens when the
kernel/rcu/tree.c: * reduce the number of grace periods during heavy kfree_rcu()/kvfree_rcu() load.
kernel/rcu/tree.c: // Probable double kfree_rcu(), just leak.
kernel/trace/trace_osnoise.c: kvfree_rcu(inst);
kernel/trace/trace_probe.c: kvfree_rcu(link);
net/core/pktgen.c: /* Don't need rcu_barrier() due to use of kfree_rcu() */
net/core/sysctl_net_core.c: kvfree_rcu(orig_sock_table);
net/core/sysctl_net_core.c: kfree_rcu(cur);
On Tue, Mar 7, 2023 at 12:22 AM Joe Perches <[email protected]> wrote:
>
> On Tue, 2023-03-07 at 00:11 -0500, Joel Fernandes wrote:
>
> > Do you mind sharing which tree you are looking at? I checked both
> > 6.3-rc1 and linux-next.
> >
> > Your grep returned:
> >
> > kernel/trace/trace_osnoise.c: kvfree_rcu(inst);
> > kernel/trace/trace_probe.c: kvfree_rcu(link);
> > lib/test_vmalloc.c: kvfree_rcu(p);
> > mm/list_lru.c: * We need kvfree_rcu() here. And the walking of the list
> > net/core/pktgen.c: /* Don't need rcu_barrier() due to use of kfree_rcu() */
> > net/core/sysctl_net_core.c:
> > kvfree_rcu(orig_sock_table);
> > net/core/sysctl_net_core.c: kfree_rcu(cur);
> > net/mac802154/scan.c: kfree_rcu(request);
> > net/mac802154/scan.c: kfree_rcu(request);
>
> rather old. I'm not subscribed and haven't been following much.
>
> Add linux-next specific files for 20230217
I am surprised though why you don't see the usage in trace_osnoise.c
though because that was added in 2021 (see diff below).
Anyway, I take it you are Ok with the checkpatch patch. If so, do
provide your Ack tag in advance. We can push from our side only if
needed. There is a chance that we may not need it if we are successful
in having made the conversions to the "good API" in time for the next
merge window.
diff --git a/kernel/trace/trace_osnoise.c b/kernel/trace/trace_osnoise.c
index 7520d43aed55..4719a848bf17 100644
--- a/kernel/trace/trace_osnoise.c
+++ b/kernel/trace/trace_osnoise.c
@@ -138,8 +138,7 @@ static void osnoise_unregister_instance(struct
trace_array *tr)
if (!found)
return;
- synchronize_rcu();
- kfree(inst);
+ kvfree_rcu(inst);
}
/*
>
> Updating to today's next:
>
> Add linux-next specific files for 20230307
>
> I get several instances:
>
> $ git grep -P '\bkv?free_rcu\s*\(' -- '*.[ch]' | grep -v -P 'kv?free_rcu\s*\([^,]+,.*\)'
> drivers/block/drbd/drbd_nl.c: kvfree_rcu(old_disk_conf);
> drivers/block/drbd/drbd_nl.c: kvfree_rcu(old_net_conf);
> drivers/block/drbd/drbd_nl.c: kvfree_rcu(old_disk_conf);
> drivers/block/drbd/drbd_receiver.c: kvfree_rcu(old_net_conf);
> drivers/block/drbd/drbd_receiver.c: kvfree_rcu(old_disk_conf);
> drivers/block/drbd/drbd_state.c: kvfree_rcu(old_conf);
> drivers/infiniband/core/device.c: kfree_rcu(container_of(dev->port_data, struct ib_port_data_rcu,
> drivers/infiniband/core/rdma_core.c: * kfree_rcu(). However the object may still have been released and
> drivers/infiniband/sw/rxe/rxe_mr.c: kfree_rcu(mr);
> drivers/misc/vmw_vmci/vmci_context.c: kvfree_rcu(notifier);
> drivers/misc/vmw_vmci/vmci_event.c: kvfree_rcu(s);
> drivers/net/ethernet/mellanox/mlx5/core/en/tc/int_port.c: kfree_rcu(int_port);
> drivers/net/ethernet/mellanox/mlx5/core/en_accel/macsec.c: kfree_rcu(tx_sa);
> drivers/net/ethernet/mellanox/mlx5/core/en_accel/macsec.c: kfree_rcu(rx_sc);
> drivers/target/target_core_configfs.c: * callbacks to complete post kfree_rcu(), before allowing
> fs/ext4/super.c: kfree_rcu(qname);
> include/linux/rcupdate.h: * kvfree_rcu(ptr);
> include/linux/rcupdate.h:#define kvfree_rcu(...) KVFREE_GET_MACRO(__VA_ARGS__, \
> include/linux/rcutiny.h: // kvfree_rcu(one_arg) call.
> include/rdma/ib_verbs.h: struct rcu_head rcu; /* kfree_rcu() overhead */
> include/scsi/scsi_device.h: * @rcu: For kfree_rcu().
> kernel/rcu/rcuscale.c: pr_alert("CONFIG_RCU_LAZY is disabled, falling back to kfree_rcu() for delayed RCU kfree'ing\n");
> kernel/rcu/tree.c: * struct kvfree_rcu_bulk_data - single block to store kvfree_rcu() pointers
> kernel/rcu/tree.c: * @records: Array of the kvfree_rcu() pointers
> kernel/rcu/tree.c: * struct kfree_rcu_cpu_work - single batch of kfree_rcu() requests
> kernel/rcu/tree.c: * @head_free: List of kfree_rcu() objects waiting for a grace period
> kernel/rcu/tree.c: * @bulk_head_free: Bulk-List of kvfree_rcu() objects waiting for a grace period
> kernel/rcu/tree.c: * struct kfree_rcu_cpu - batch up kfree_rcu() requests for RCU grace period
> kernel/rcu/tree.c: * @head: List of kfree_rcu() objects not yet waiting for a grace period
> kernel/rcu/tree.c: * @bulk_head: Bulk-List of kvfree_rcu() objects not yet waiting for a grace period
> kernel/rcu/tree.c: * @krw_arr: Array of batches of kfree_rcu() objects waiting for a grace period
> kernel/rcu/tree.c: * double-argument of kvfree_rcu(). This happens when the
> kernel/rcu/tree.c: * reduce the number of grace periods during heavy kfree_rcu()/kvfree_rcu() load.
> kernel/rcu/tree.c: // Probable double kfree_rcu(), just leak.
> kernel/trace/trace_osnoise.c: kvfree_rcu(inst);
> kernel/trace/trace_probe.c: kvfree_rcu(link);
> net/core/pktgen.c: /* Don't need rcu_barrier() due to use of kfree_rcu() */
> net/core/sysctl_net_core.c: kvfree_rcu(orig_sock_table);
> net/core/sysctl_net_core.c: kfree_rcu(cur);
>