Fastest existing Bluetooth standard's top speed is 2.4 MB/s.
It is way off from being CPU limited, no need to squeeze
last few cycles by excessive inlining.
This patch delinlines the following functions:
hci_conn_hash_lookup_handle: 345 bytes, 39 calls
hci_conn_hash_lookup_ba: 372 bytes, 36 calls
hci_conn_hash_lookup_le: 382 bytes, 8 calls
hci_conn_hash_lookup_state: 356 bytes, 3 calls
hci_lookup_le_connect: 378 bytes, 7 calls
hci_conn_drop: 186 bytes, 30 calls
hci_connect_cfm: 121 bytes, 15 calls
hci_disconn_cfm: 121 bytes, 2 calls
hci_auth_cfm: 156 bytes, 2 calls
hci_encrypt_cfm: 156 bytes, 3 calls
Size reduction is about 40k:
text data bss dec hex filename
95943139 20860256 35991552 152794947 91b7743 vmlinux_before
95903714 20860256 35991552 152755522 91add42 vmlinux
Signed-off-by: Denys Vlasenko <[email protected]>
CC: Johan Hedberg <[email protected]>
CC: [email protected]
CC: [email protected]
---
include/net/bluetooth/hci_core.h | 219 +++------------------------------------
net/bluetooth/hci_core.c | 211 +++++++++++++++++++++++++++++++++++++
2 files changed, 227 insertions(+), 203 deletions(-)
diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index d4f82ed..0cd798e 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -761,108 +761,20 @@ static inline __u8 hci_conn_lookup_type(struct hci_dev *hdev, __u16 handle)
return type;
}
-static inline struct hci_conn *hci_conn_hash_lookup_handle(struct hci_dev *hdev,
- __u16 handle)
-{
- struct hci_conn_hash *h = &hdev->conn_hash;
- struct hci_conn *c;
-
- rcu_read_lock();
-
- list_for_each_entry_rcu(c, &h->list, list) {
- if (c->handle == handle) {
- rcu_read_unlock();
- return c;
- }
- }
- rcu_read_unlock();
-
- return NULL;
-}
-
-static inline struct hci_conn *hci_conn_hash_lookup_ba(struct hci_dev *hdev,
- __u8 type, bdaddr_t *ba)
-{
- struct hci_conn_hash *h = &hdev->conn_hash;
- struct hci_conn *c;
-
- rcu_read_lock();
-
- list_for_each_entry_rcu(c, &h->list, list) {
- if (c->type == type && !bacmp(&c->dst, ba)) {
- rcu_read_unlock();
- return c;
- }
- }
-
- rcu_read_unlock();
-
- return NULL;
-}
-
-static inline struct hci_conn *hci_conn_hash_lookup_le(struct hci_dev *hdev,
- bdaddr_t *ba,
- __u8 ba_type)
-{
- struct hci_conn_hash *h = &hdev->conn_hash;
- struct hci_conn *c;
+struct hci_conn *hci_conn_hash_lookup_handle(struct hci_dev *hdev,
+ __u16 handle);
- rcu_read_lock();
-
- list_for_each_entry_rcu(c, &h->list, list) {
- if (c->type != LE_LINK)
- continue;
-
- if (ba_type == c->dst_type && !bacmp(&c->dst, ba)) {
- rcu_read_unlock();
- return c;
- }
- }
-
- rcu_read_unlock();
-
- return NULL;
-}
-
-static inline struct hci_conn *hci_conn_hash_lookup_state(struct hci_dev *hdev,
- __u8 type, __u16 state)
-{
- struct hci_conn_hash *h = &hdev->conn_hash;
- struct hci_conn *c;
-
- rcu_read_lock();
-
- list_for_each_entry_rcu(c, &h->list, list) {
- if (c->type == type && c->state == state) {
- rcu_read_unlock();
- return c;
- }
- }
-
- rcu_read_unlock();
-
- return NULL;
-}
-
-static inline struct hci_conn *hci_lookup_le_connect(struct hci_dev *hdev)
-{
- struct hci_conn_hash *h = &hdev->conn_hash;
- struct hci_conn *c;
-
- rcu_read_lock();
+struct hci_conn *hci_conn_hash_lookup_ba(struct hci_dev *hdev,
+ __u8 type, bdaddr_t *ba);
- list_for_each_entry_rcu(c, &h->list, list) {
- if (c->type == LE_LINK && c->state == BT_CONNECT &&
- !test_bit(HCI_CONN_SCANNING, &c->flags)) {
- rcu_read_unlock();
- return c;
- }
- }
+struct hci_conn *hci_conn_hash_lookup_le(struct hci_dev *hdev,
+ bdaddr_t *ba,
+ __u8 ba_type);
- rcu_read_unlock();
+struct hci_conn *hci_conn_hash_lookup_state(struct hci_dev *hdev,
+ __u8 type, __u16 state);
- return NULL;
-}
+struct hci_conn *hci_lookup_le_connect(struct hci_dev *hdev);
int hci_disconnect(struct hci_conn *conn, __u8 reason);
bool hci_setup_sync(struct hci_conn *conn, __u16 handle);
@@ -939,40 +851,7 @@ static inline void hci_conn_hold(struct hci_conn *conn)
cancel_delayed_work(&conn->disc_work);
}
-static inline void hci_conn_drop(struct hci_conn *conn)
-{
- BT_DBG("hcon %p orig refcnt %d", conn, atomic_read(&conn->refcnt));
-
- if (atomic_dec_and_test(&conn->refcnt)) {
- unsigned long timeo;
-
- switch (conn->type) {
- case ACL_LINK:
- case LE_LINK:
- cancel_delayed_work(&conn->idle_work);
- if (conn->state == BT_CONNECTED) {
- timeo = conn->disc_timeout;
- if (!conn->out)
- timeo *= 2;
- } else {
- timeo = 0;
- }
- break;
-
- case AMP_LINK:
- timeo = conn->disc_timeout;
- break;
-
- default:
- timeo = 0;
- break;
- }
-
- cancel_delayed_work(&conn->disc_work);
- queue_delayed_work(conn->hdev->workqueue,
- &conn->disc_work, timeo);
- }
-}
+void hci_conn_drop(struct hci_conn *conn);
/* ----- HCI Devices ----- */
static inline void hci_dev_put(struct hci_dev *d)
@@ -1186,78 +1065,12 @@ struct hci_cb {
void (*role_switch_cfm) (struct hci_conn *conn, __u8 status, __u8 role);
};
-static inline void hci_connect_cfm(struct hci_conn *conn, __u8 status)
-{
- struct hci_cb *cb;
-
- mutex_lock(&hci_cb_list_lock);
- list_for_each_entry(cb, &hci_cb_list, list) {
- if (cb->connect_cfm)
- cb->connect_cfm(conn, status);
- }
- mutex_unlock(&hci_cb_list_lock);
-
- if (conn->connect_cfm_cb)
- conn->connect_cfm_cb(conn, status);
-}
-
-static inline void hci_disconn_cfm(struct hci_conn *conn, __u8 reason)
-{
- struct hci_cb *cb;
-
- mutex_lock(&hci_cb_list_lock);
- list_for_each_entry(cb, &hci_cb_list, list) {
- if (cb->disconn_cfm)
- cb->disconn_cfm(conn, reason);
- }
- mutex_unlock(&hci_cb_list_lock);
-
- if (conn->disconn_cfm_cb)
- conn->disconn_cfm_cb(conn, reason);
-}
-
-static inline void hci_auth_cfm(struct hci_conn *conn, __u8 status)
-{
- struct hci_cb *cb;
- __u8 encrypt;
-
- if (test_bit(HCI_CONN_ENCRYPT_PEND, &conn->flags))
- return;
-
- encrypt = test_bit(HCI_CONN_ENCRYPT, &conn->flags) ? 0x01 : 0x00;
-
- mutex_lock(&hci_cb_list_lock);
- list_for_each_entry(cb, &hci_cb_list, list) {
- if (cb->security_cfm)
- cb->security_cfm(conn, status, encrypt);
- }
- mutex_unlock(&hci_cb_list_lock);
-
- if (conn->security_cfm_cb)
- conn->security_cfm_cb(conn, status);
-}
-
-static inline void hci_encrypt_cfm(struct hci_conn *conn, __u8 status,
- __u8 encrypt)
-{
- struct hci_cb *cb;
-
- if (conn->sec_level == BT_SECURITY_SDP)
- conn->sec_level = BT_SECURITY_LOW;
+void hci_connect_cfm(struct hci_conn *conn, __u8 status);
+void hci_disconn_cfm(struct hci_conn *conn, __u8 reason);
- if (conn->pending_sec_level > conn->sec_level)
- conn->sec_level = conn->pending_sec_level;
-
- mutex_lock(&hci_cb_list_lock);
- list_for_each_entry(cb, &hci_cb_list, list) {
- if (cb->security_cfm)
- cb->security_cfm(conn, status, encrypt);
- }
- mutex_unlock(&hci_cb_list_lock);
-
- if (conn->security_cfm_cb)
- conn->security_cfm_cb(conn, status);
-}
+void hci_auth_cfm(struct hci_conn *conn, __u8 status);
+void hci_encrypt_cfm(struct hci_conn *conn, __u8 status,
+ __u8 encrypt);
static inline void hci_key_change_cfm(struct hci_conn *conn, __u8 status)
{
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 883c821..9ff3d60 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -56,6 +56,217 @@ DEFINE_MUTEX(hci_cb_list_lock);
/* HCI ID Numbering */
static DEFINE_IDA(hci_index_ida);
+struct hci_conn *hci_conn_hash_lookup_handle(struct hci_dev *hdev,
+ __u16 handle)
+{
+ struct hci_conn_hash *h = &hdev->conn_hash;
+ struct hci_conn *c;
+
+ rcu_read_lock();
+
+ list_for_each_entry_rcu(c, &h->list, list) {
+ if (c->handle == handle) {
+ rcu_read_unlock();
+ return c;
+ }
+ }
+ rcu_read_unlock();
+
+ return NULL;
+}
+
+struct hci_conn *hci_conn_hash_lookup_ba(struct hci_dev *hdev,
+ __u8 type, bdaddr_t *ba)
+{
+ struct hci_conn_hash *h = &hdev->conn_hash;
+ struct hci_conn *c;
+
+ rcu_read_lock();
+
+ list_for_each_entry_rcu(c, &h->list, list) {
+ if (c->type == type && !bacmp(&c->dst, ba)) {
+ rcu_read_unlock();
+ return c;
+ }
+ }
+
+ rcu_read_unlock();
+
+ return NULL;
+}
+
+struct hci_conn *hci_conn_hash_lookup_le(struct hci_dev *hdev,
+ bdaddr_t *ba,
+ __u8 ba_type)
+{
+ struct hci_conn_hash *h = &hdev->conn_hash;
+ struct hci_conn *c;
+
+ rcu_read_lock();
+
+ list_for_each_entry_rcu(c, &h->list, list) {
+ if (c->type != LE_LINK)
+ continue;
+
+ if (ba_type == c->dst_type && !bacmp(&c->dst, ba)) {
+ rcu_read_unlock();
+ return c;
+ }
+ }
+
+ rcu_read_unlock();
+
+ return NULL;
+}
+
+struct hci_conn *hci_conn_hash_lookup_state(struct hci_dev *hdev,
+ __u8 type, __u16 state)
+{
+ struct hci_conn_hash *h = &hdev->conn_hash;
+ struct hci_conn *c;
+
+ rcu_read_lock();
+
+ list_for_each_entry_rcu(c, &h->list, list) {
+ if (c->type == type && c->state == state) {
+ rcu_read_unlock();
+ return c;
+ }
+ }
+
+ rcu_read_unlock();
+
+ return NULL;
+}
+
+struct hci_conn *hci_lookup_le_connect(struct hci_dev *hdev)
+{
+ struct hci_conn_hash *h = &hdev->conn_hash;
+ struct hci_conn *c;
+
+ rcu_read_lock();
+
+ list_for_each_entry_rcu(c, &h->list, list) {
+ if (c->type == LE_LINK && c->state == BT_CONNECT &&
+ !test_bit(HCI_CONN_SCANNING, &c->flags)) {
+ rcu_read_unlock();
+ return c;
+ }
+ }
+
+ rcu_read_unlock();
+
+ return NULL;
+}
+
+void hci_conn_drop(struct hci_conn *conn)
+{
+ BT_DBG("hcon %p orig refcnt %d", conn, atomic_read(&conn->refcnt));
+
+ if (atomic_dec_and_test(&conn->refcnt)) {
+ unsigned long timeo;
+
+ switch (conn->type) {
+ case ACL_LINK:
+ case LE_LINK:
+ cancel_delayed_work(&conn->idle_work);
+ if (conn->state == BT_CONNECTED) {
+ timeo = conn->disc_timeout;
+ if (!conn->out)
+ timeo *= 2;
+ } else {
+ timeo = 0;
+ }
+ break;
+
+ case AMP_LINK:
+ timeo = conn->disc_timeout;
+ break;
+
+ default:
+ timeo = 0;
+ break;
+ }
+
+ cancel_delayed_work(&conn->disc_work);
+ queue_delayed_work(conn->hdev->workqueue,
+ &conn->disc_work, timeo);
+ }
+}
+
+void hci_connect_cfm(struct hci_conn *conn, __u8 status)
+{
+ struct hci_cb *cb;
+
+ mutex_lock(&hci_cb_list_lock);
+ list_for_each_entry(cb, &hci_cb_list, list) {
+ if (cb->connect_cfm)
+ cb->connect_cfm(conn, status);
+ }
+ mutex_unlock(&hci_cb_list_lock);
+
+ if (conn->connect_cfm_cb)
+ conn->connect_cfm_cb(conn, status);
+}
+
+void hci_disconn_cfm(struct hci_conn *conn, __u8 reason)
+{
+ struct hci_cb *cb;
+
+ mutex_lock(&hci_cb_list_lock);
+ list_for_each_entry(cb, &hci_cb_list, list) {
+ if (cb->disconn_cfm)
+ cb->disconn_cfm(conn, reason);
+ }
+ mutex_unlock(&hci_cb_list_lock);
+
+ if (conn->disconn_cfm_cb)
+ conn->disconn_cfm_cb(conn, reason);
+}
+
+void hci_auth_cfm(struct hci_conn *conn, __u8 status)
+{
+ struct hci_cb *cb;
+ __u8 encrypt;
+
+ if (test_bit(HCI_CONN_ENCRYPT_PEND, &conn->flags))
+ return;
+
+ encrypt = test_bit(HCI_CONN_ENCRYPT, &conn->flags) ? 0x01 : 0x00;
+
+ mutex_lock(&hci_cb_list_lock);
+ list_for_each_entry(cb, &hci_cb_list, list) {
+ if (cb->security_cfm)
+ cb->security_cfm(conn, status, encrypt);
+ }
+ mutex_unlock(&hci_cb_list_lock);
+
+ if (conn->security_cfm_cb)
+ conn->security_cfm_cb(conn, status);
+}
+
+void hci_encrypt_cfm(struct hci_conn *conn, __u8 status,
+ __u8 encrypt)
+{
+ struct hci_cb *cb;
+
+ if (conn->sec_level == BT_SECURITY_SDP)
+ conn->sec_level = BT_SECURITY_LOW;
+
+ if (conn->pending_sec_level > conn->sec_level)
+ conn->sec_level = conn->pending_sec_level;
+
+ mutex_lock(&hci_cb_list_lock);
+ list_for_each_entry(cb, &hci_cb_list, list) {
+ if (cb->security_cfm)
+ cb->security_cfm(conn, status, encrypt);
+ }
+ mutex_unlock(&hci_cb_list_lock);
+
+ if (conn->security_cfm_cb)
+ conn->security_cfm_cb(conn, status);
+}
+
/* ---- HCI debugfs entries ---- */
static ssize_t dut_mode_read(struct file *file, char __user *user_buf,
--
1.8.1.4
On Sun, 2016-04-10 at 18:24 +0200, Denys Vlasenko wrote:
> Fastest existing Bluetooth standard's top speed is 2.4 MB/s.
> It is way off from being CPU limited, no need to squeeze
> last few cycles by excessive inlining.
>
> This patch delinlines the following functions:
>
> hci_conn_hash_lookup_handle: 345 bytes, 39 calls
> hci_conn_hash_lookup_ba: 372 bytes, 36 calls
> hci_conn_hash_lookup_le: 382 bytes, 8 calls
> hci_conn_hash_lookup_state: 356 bytes, 3 calls
> hci_lookup_le_connect: 378 bytes, 7 calls
> hci_conn_drop: 186 bytes, 30 calls
> hci_connect_cfm: 121 bytes, 15 calls
> hci_disconn_cfm: 121 bytes, 2 calls
> hci_auth_cfm: 156 bytes, 2 calls
> hci_encrypt_cfm: 156 bytes, 3 calls
>
> Size reduction is about 40k:
>
> ????text?????data??????bss???????dec?????hex filename
> 95943139 20860256 35991552 152794947 91b7743 vmlinux_before
> 95903714 20860256 35991552 152755522 91add42 vmlinux
Hello Denys
While removing unnecessary inlines is generally a
good thing, for extremely low power embedded systems
like a coin-battery operated bicycle computer or a
heart rate monitor, this might cause a throughput
reduction.
Also, the size decrease for a defconfig should be
quite a bit smaller than this.
Can you please also show the size decrease when done
with a defconfig with bluetooth support?
And for these types of patches in general, please
add a defconfig size reduction to the commit message.
This is an x86-64 defconfig with bluetooth with and
without this patch:
$ size vmlinux.defconfig.*
???text ???data ????bss ????dec ????hex filename
10214414 4313816 1097728 15625958 ?ee6ee6 vmlinux.defconfig.new
10224014 4313816 1097728 15635558 ?ee9466 vmlinux.defconfig.old
~10k total
On Sun, Apr 10, 2016 at 6:59 PM, Joe Perches <[email protected]> wrote:
> On Sun, 2016-04-10 at 18:24 +0200, Denys Vlasenko wrote:
>> Fastest existing Bluetooth standard's top speed is 2.4 MB/s.
>> It is way off from being CPU limited, no need to squeeze
>> last few cycles by excessive inlining.
>>
>> This patch delinlines the following functions:
>>
>> hci_conn_hash_lookup_handle: 345 bytes, 39 calls
>> hci_conn_hash_lookup_ba: 372 bytes, 36 calls
>> hci_conn_hash_lookup_le: 382 bytes, 8 calls
>> hci_conn_hash_lookup_state: 356 bytes, 3 calls
>> hci_lookup_le_connect: 378 bytes, 7 calls
>> hci_conn_drop: 186 bytes, 30 calls
>> hci_connect_cfm: 121 bytes, 15 calls
>> hci_disconn_cfm: 121 bytes, 2 calls
>> hci_auth_cfm: 156 bytes, 2 calls
>> hci_encrypt_cfm: 156 bytes, 3 calls
>>
>> Size reduction is about 40k:
>>
>> text data bss dec hex filename
>> 95943139 20860256 35991552 152794947 91b7743 vmlinux_before
>> 95903714 20860256 35991552 152755522 91add42 vmlinux
>
> Hello Denys
>
> While removing unnecessary inlines is generally a
> good thing, for extremely low power embedded systems
> like a coin-battery operated bicycle computer or a
> heart rate monitor, this might cause a throughput
> reduction.
Todays CPUs can push several GB/s over, say, Ethernet.
BT is 2.4 MB/s, tops.
Therefore total CPU time spent preparing BT I/O must be
in the 0.1% ballpark. (Meaning, if we would have a magical
infinitely fast CPU, throughput would possibly increase
by about 0.1%). How much do you think this deinlining patch
can possibly hurt here?
> Can you please also show the size decrease when done
> with a defconfig with bluetooth support?
>
> And for these types of patches in general, please
> add a defconfig size reduction to the commit message.
Okay, will do in the future.
> This is an x86-64 defconfig with bluetooth with and
> without this patch:
>
> $ size vmlinux.defconfig.*
> text data bss dec hex filename
> 10214414 4313816 1097728 15625958 ee6ee6 vmlinux.defconfig.new
> 10224014 4313816 1097728 15635558 ee9466 vmlinux.defconfig.old
>
> ~10k total
Looks good, right?
Hi Denys,
[auto build test ERROR on bluetooth-next/master]
[also build test ERROR on v4.6-rc2 next-20160408]
[if your patch is applied to the wrong git tree, please drop us a note to help improving the system]
url: https://github.com/0day-ci/linux/commits/Denys-Vlasenko/Bluetooth-Deinline-large-functions/20160411-002558
base: https://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth-next.git master
config: i386-allmodconfig (attached as .config)
reproduce:
# save the attached .config to linux build tree
make ARCH=i386
All errors (new ones prefixed by >>):
>> ERROR: "hci_conn_hash_lookup_ba" [net/bluetooth/rfcomm/rfcomm.ko] undefined!
>> ERROR: "hci_conn_hash_lookup_le" [net/bluetooth/bluetooth_6lowpan.ko] undefined!
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
On Sun, 2016-04-10 at 19:18 +0200, Denys Vlasenko wrote:
> On Sun, Apr 10, 2016 at 6:59 PM, Joe Perches <[email protected]> wrote:
> >
> > On Sun, 2016-04-10 at 18:24 +0200, Denys Vlasenko wrote:
> > >
> > > Fastest existing Bluetooth standard's top speed is 2.4 MB/s.
> > > It is way off from being CPU limited, no need to squeeze
> > > last few cycles by excessive inlining.
> > >
> > > This patch delinlines the following functions:
> > >
> > > hci_conn_hash_lookup_handle: 345 bytes, 39 calls
> > > hci_conn_hash_lookup_ba: 372 bytes, 36 calls
> > > hci_conn_hash_lookup_le: 382 bytes, 8 calls
> > > hci_conn_hash_lookup_state: 356 bytes, 3 calls
> > > hci_lookup_le_connect: 378 bytes, 7 calls
> > > hci_conn_drop: 186 bytes, 30 calls
> > > hci_connect_cfm: 121 bytes, 15 calls
> > > hci_disconn_cfm: 121 bytes, 2 calls
> > > hci_auth_cfm: 156 bytes, 2 calls
> > > hci_encrypt_cfm: 156 bytes, 3 calls
> > >
> > > Size reduction is about 40k:
> > >
> > > ????text?????data??????bss???????dec?????hex filename
> > > 95943139 20860256 35991552 152794947 91b7743 vmlinux_before
> > > 95903714 20860256 35991552 152755522 91add42 vmlinux
> > Hello Denys
> >
> > While removing unnecessary inlines is generally a
> > good thing, for extremely low power embedded systems
> > like a coin-battery operated bicycle computer or a
> > heart rate monitor, this might cause a throughput
> > reduction.
> Todays CPUs can push several GB/s over, say, Ethernet.
> BT is 2.4 MB/s, tops.
> Therefore total CPU time spent preparing BT I/O must be
> in the 0.1% ballpark. (Meaning, if we would have a magical
> infinitely fast CPU, throughput would possibly increase
> by about 0.1%). How much do you think this deinlining patch
> can possibly hurt here?
Today's extremely low power ARM chips that run
at a couple dozen MHz
cannot push gigabit speeds.
> > Can you please also show the size decrease when done
> > with a defconfig with bluetooth support?
> >
> > And for these types of patches in general, please
> > add a defconfig size reduction to the commit message.
> Okay, will do in the future.
>
> >
> > This is an x86-64 defconfig with bluetooth with and
> > without this patch:
> >
> > $ size vmlinux.defconfig.*
> > ???text????data?????bss?????dec?????hex filename
> > 10214414????????4313816 1097728 15625958?????????ee6ee6 vmlinux.defconfig.new
> > 10224014????????4313816 1097728 15635558?????????ee9466 vmlinux.defconfig.old
> >
> > ~10k total
> Looks good, right?
Size reductions are generally good.
The one function that might be appropriate to leave inline
is perhaps hci_conn_hash_lookup_handle. ?Dunno.
It's be good to test though.