* [PATCH] locking: Add __lockfunc to slow path functions
@ 2022-08-08 17:59 Namhyung Kim
2022-08-09 15:05 ` Waiman Long
0 siblings, 1 reply; 6+ messages in thread
From: Namhyung Kim @ 2022-08-08 17:59 UTC (permalink / raw)
To: Peter Zijlstra, Ingo Molnar, Will Deacon; +Cc: Waiman Long, Boqun Feng, LKML
So that we can skip the functions in the perf lock contention and other
places like /proc/PID/wchan.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
kernel/locking/qrwlock.c | 4 ++--
kernel/locking/qspinlock.c | 2 +-
2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/kernel/locking/qrwlock.c b/kernel/locking/qrwlock.c
index 2e1600906c9f..d2ef312a8611 100644
--- a/kernel/locking/qrwlock.c
+++ b/kernel/locking/qrwlock.c
@@ -18,7 +18,7 @@
* queued_read_lock_slowpath - acquire read lock of a queued rwlock
* @lock: Pointer to queued rwlock structure
*/
-void queued_read_lock_slowpath(struct qrwlock *lock)
+void __lockfunc queued_read_lock_slowpath(struct qrwlock *lock)
{
/*
* Readers come here when they cannot get the lock without waiting
@@ -63,7 +63,7 @@ EXPORT_SYMBOL(queued_read_lock_slowpath);
* queued_write_lock_slowpath - acquire write lock of a queued rwlock
* @lock : Pointer to queued rwlock structure
*/
-void queued_write_lock_slowpath(struct qrwlock *lock)
+void __lockfunc queued_write_lock_slowpath(struct qrwlock *lock)
{
int cnts;
diff --git a/kernel/locking/qspinlock.c b/kernel/locking/qspinlock.c
index 65a9a10caa6f..2b23378775fe 100644
--- a/kernel/locking/qspinlock.c
+++ b/kernel/locking/qspinlock.c
@@ -313,7 +313,7 @@ static __always_inline u32 __pv_wait_head_or_lock(struct qspinlock *lock,
* contended : (*,x,y) +--> (*,0,0) ---> (*,0,1) -' :
* queue : ^--' :
*/
-void queued_spin_lock_slowpath(struct qspinlock *lock, u32 val)
+void __lockfunc queued_spin_lock_slowpath(struct qspinlock *lock, u32 val)
{
struct mcs_spinlock *prev, *next, *node;
u32 old, tail;
--
2.37.1.559.g78731f0fdb-goog
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] locking: Add __lockfunc to slow path functions
2022-08-08 17:59 [PATCH] locking: Add __lockfunc to slow path functions Namhyung Kim
@ 2022-08-09 15:05 ` Waiman Long
2022-08-09 21:13 ` Namhyung Kim
0 siblings, 1 reply; 6+ messages in thread
From: Waiman Long @ 2022-08-09 15:05 UTC (permalink / raw)
To: Namhyung Kim, Peter Zijlstra, Ingo Molnar, Will Deacon; +Cc: Boqun Feng, LKML
On 8/8/22 13:59, Namhyung Kim wrote:
> So that we can skip the functions in the perf lock contention and other
> places like /proc/PID/wchan.
>
> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> ---
> kernel/locking/qrwlock.c | 4 ++--
> kernel/locking/qspinlock.c | 2 +-
> 2 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/kernel/locking/qrwlock.c b/kernel/locking/qrwlock.c
> index 2e1600906c9f..d2ef312a8611 100644
> --- a/kernel/locking/qrwlock.c
> +++ b/kernel/locking/qrwlock.c
> @@ -18,7 +18,7 @@
> * queued_read_lock_slowpath - acquire read lock of a queued rwlock
> * @lock: Pointer to queued rwlock structure
> */
> -void queued_read_lock_slowpath(struct qrwlock *lock)
> +void __lockfunc queued_read_lock_slowpath(struct qrwlock *lock)
> {
> /*
> * Readers come here when they cannot get the lock without waiting
> @@ -63,7 +63,7 @@ EXPORT_SYMBOL(queued_read_lock_slowpath);
> * queued_write_lock_slowpath - acquire write lock of a queued rwlock
> * @lock : Pointer to queued rwlock structure
> */
> -void queued_write_lock_slowpath(struct qrwlock *lock)
> +void __lockfunc queued_write_lock_slowpath(struct qrwlock *lock)
> {
> int cnts;
>
> diff --git a/kernel/locking/qspinlock.c b/kernel/locking/qspinlock.c
> index 65a9a10caa6f..2b23378775fe 100644
> --- a/kernel/locking/qspinlock.c
> +++ b/kernel/locking/qspinlock.c
> @@ -313,7 +313,7 @@ static __always_inline u32 __pv_wait_head_or_lock(struct qspinlock *lock,
> * contended : (*,x,y) +--> (*,0,0) ---> (*,0,1) -' :
> * queue : ^--' :
> */
> -void queued_spin_lock_slowpath(struct qspinlock *lock, u32 val)
> +void __lockfunc queued_spin_lock_slowpath(struct qspinlock *lock, u32 val)
> {
> struct mcs_spinlock *prev, *next, *node;
> u32 old, tail;
For completeness, I think you should also add it to the
__pv_queued_spin_unlock() and __pv_queued_spin_unlock_slowpath()
function in kernel/locking/qspinlock_paravirt.h. Perhaps even the
assembly code in arch/x86/include/asm/qspinlock_paravirt.h.
Cheers,
Longman
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] locking: Add __lockfunc to slow path functions
2022-08-09 15:05 ` Waiman Long
@ 2022-08-09 21:13 ` Namhyung Kim
2022-08-09 23:09 ` Waiman Long
0 siblings, 1 reply; 6+ messages in thread
From: Namhyung Kim @ 2022-08-09 21:13 UTC (permalink / raw)
To: Waiman Long; +Cc: Peter Zijlstra, Ingo Molnar, Will Deacon, Boqun Feng, LKML
Hello,
On Tue, Aug 9, 2022 at 8:05 AM Waiman Long <longman@redhat.com> wrote:
>
> On 8/8/22 13:59, Namhyung Kim wrote:
> > So that we can skip the functions in the perf lock contention and other
> > places like /proc/PID/wchan.
> >
> > Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> > ---
> > kernel/locking/qrwlock.c | 4 ++--
> > kernel/locking/qspinlock.c | 2 +-
> > 2 files changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/kernel/locking/qrwlock.c b/kernel/locking/qrwlock.c
> > index 2e1600906c9f..d2ef312a8611 100644
> > --- a/kernel/locking/qrwlock.c
> > +++ b/kernel/locking/qrwlock.c
> > @@ -18,7 +18,7 @@
> > * queued_read_lock_slowpath - acquire read lock of a queued rwlock
> > * @lock: Pointer to queued rwlock structure
> > */
> > -void queued_read_lock_slowpath(struct qrwlock *lock)
> > +void __lockfunc queued_read_lock_slowpath(struct qrwlock *lock)
> > {
> > /*
> > * Readers come here when they cannot get the lock without waiting
> > @@ -63,7 +63,7 @@ EXPORT_SYMBOL(queued_read_lock_slowpath);
> > * queued_write_lock_slowpath - acquire write lock of a queued rwlock
> > * @lock : Pointer to queued rwlock structure
> > */
> > -void queued_write_lock_slowpath(struct qrwlock *lock)
> > +void __lockfunc queued_write_lock_slowpath(struct qrwlock *lock)
> > {
> > int cnts;
> >
> > diff --git a/kernel/locking/qspinlock.c b/kernel/locking/qspinlock.c
> > index 65a9a10caa6f..2b23378775fe 100644
> > --- a/kernel/locking/qspinlock.c
> > +++ b/kernel/locking/qspinlock.c
> > @@ -313,7 +313,7 @@ static __always_inline u32 __pv_wait_head_or_lock(struct qspinlock *lock,
> > * contended : (*,x,y) +--> (*,0,0) ---> (*,0,1) -' :
> > * queue : ^--' :
> > */
> > -void queued_spin_lock_slowpath(struct qspinlock *lock, u32 val)
> > +void __lockfunc queued_spin_lock_slowpath(struct qspinlock *lock, u32 val)
> > {
> > struct mcs_spinlock *prev, *next, *node;
> > u32 old, tail;
>
>
> For completeness, I think you should also add it to the
> __pv_queued_spin_unlock() and __pv_queued_spin_unlock_slowpath()
> function in kernel/locking/qspinlock_paravirt.h. Perhaps even the
> assembly code in arch/x86/include/asm/qspinlock_paravirt.h.
Thanks for your comment. I'm not sure about the asm part, will this be enough?
--- a/arch/x86/include/asm/qspinlock_paravirt.h
+++ b/arch/x86/include/asm/qspinlock_paravirt.h
@@ -36,7 +36,7 @@ PV_CALLEE_SAVE_REGS_THUNK(__pv_queued_spin_unlock_slowpath);
* rsi = lockval (second argument)
* rdx = internal variable (set to 0)
*/
-asm (".pushsection .text;"
+asm (".pushsection .spinlock.text;"
".globl " PV_UNLOCK ";"
".type " PV_UNLOCK ", @function;"
".align 4,0x90;"
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] locking: Add __lockfunc to slow path functions
2022-08-09 21:13 ` Namhyung Kim
@ 2022-08-09 23:09 ` Waiman Long
2022-08-09 23:37 ` Namhyung Kim
0 siblings, 1 reply; 6+ messages in thread
From: Waiman Long @ 2022-08-09 23:09 UTC (permalink / raw)
To: Namhyung Kim; +Cc: Peter Zijlstra, Ingo Molnar, Will Deacon, Boqun Feng, LKML
On 8/9/22 17:13, Namhyung Kim wrote:
> Hello,
>
> On Tue, Aug 9, 2022 at 8:05 AM Waiman Long <longman@redhat.com> wrote:
>> On 8/8/22 13:59, Namhyung Kim wrote:
>>> So that we can skip the functions in the perf lock contention and other
>>> places like /proc/PID/wchan.
>>>
>>> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
>>> ---
>>> kernel/locking/qrwlock.c | 4 ++--
>>> kernel/locking/qspinlock.c | 2 +-
>>> 2 files changed, 3 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/kernel/locking/qrwlock.c b/kernel/locking/qrwlock.c
>>> index 2e1600906c9f..d2ef312a8611 100644
>>> --- a/kernel/locking/qrwlock.c
>>> +++ b/kernel/locking/qrwlock.c
>>> @@ -18,7 +18,7 @@
>>> * queued_read_lock_slowpath - acquire read lock of a queued rwlock
>>> * @lock: Pointer to queued rwlock structure
>>> */
>>> -void queued_read_lock_slowpath(struct qrwlock *lock)
>>> +void __lockfunc queued_read_lock_slowpath(struct qrwlock *lock)
>>> {
>>> /*
>>> * Readers come here when they cannot get the lock without waiting
>>> @@ -63,7 +63,7 @@ EXPORT_SYMBOL(queued_read_lock_slowpath);
>>> * queued_write_lock_slowpath - acquire write lock of a queued rwlock
>>> * @lock : Pointer to queued rwlock structure
>>> */
>>> -void queued_write_lock_slowpath(struct qrwlock *lock)
>>> +void __lockfunc queued_write_lock_slowpath(struct qrwlock *lock)
>>> {
>>> int cnts;
>>>
>>> diff --git a/kernel/locking/qspinlock.c b/kernel/locking/qspinlock.c
>>> index 65a9a10caa6f..2b23378775fe 100644
>>> --- a/kernel/locking/qspinlock.c
>>> +++ b/kernel/locking/qspinlock.c
>>> @@ -313,7 +313,7 @@ static __always_inline u32 __pv_wait_head_or_lock(struct qspinlock *lock,
>>> * contended : (*,x,y) +--> (*,0,0) ---> (*,0,1) -' :
>>> * queue : ^--' :
>>> */
>>> -void queued_spin_lock_slowpath(struct qspinlock *lock, u32 val)
>>> +void __lockfunc queued_spin_lock_slowpath(struct qspinlock *lock, u32 val)
>>> {
>>> struct mcs_spinlock *prev, *next, *node;
>>> u32 old, tail;
>>
>> For completeness, I think you should also add it to the
>> __pv_queued_spin_unlock() and __pv_queued_spin_unlock_slowpath()
>> function in kernel/locking/qspinlock_paravirt.h. Perhaps even the
>> assembly code in arch/x86/include/asm/qspinlock_paravirt.h.
> Thanks for your comment. I'm not sure about the asm part, will this be enough?
>
> --- a/arch/x86/include/asm/qspinlock_paravirt.h
> +++ b/arch/x86/include/asm/qspinlock_paravirt.h
> @@ -36,7 +36,7 @@ PV_CALLEE_SAVE_REGS_THUNK(__pv_queued_spin_unlock_slowpath);
> * rsi = lockval (second argument)
> * rdx = internal variable (set to 0)
> */
> -asm (".pushsection .text;"
> +asm (".pushsection .spinlock.text;"
> ".globl " PV_UNLOCK ";"
> ".type " PV_UNLOCK ", @function;"
> ".align 4,0x90;"
>
That is what I meant. However, you should also a comment saying that the
use of .spinlock.text section is equivalent to the use of __lockfunc on
an equivalent C function to make it clear. Also add the __lockfunc to
the pseudo code in the comment section.
Cheers,
Longman
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] locking: Add __lockfunc to slow path functions
2022-08-09 23:09 ` Waiman Long
@ 2022-08-09 23:37 ` Namhyung Kim
2022-08-10 21:00 ` Namhyung Kim
0 siblings, 1 reply; 6+ messages in thread
From: Namhyung Kim @ 2022-08-09 23:37 UTC (permalink / raw)
To: Waiman Long; +Cc: Peter Zijlstra, Ingo Molnar, Will Deacon, Boqun Feng, LKML
On Tue, Aug 9, 2022 at 4:09 PM Waiman Long <longman@redhat.com> wrote:
>
> On 8/9/22 17:13, Namhyung Kim wrote:
> > --- a/arch/x86/include/asm/qspinlock_paravirt.h
> > +++ b/arch/x86/include/asm/qspinlock_paravirt.h
> > @@ -36,7 +36,7 @@ PV_CALLEE_SAVE_REGS_THUNK(__pv_queued_spin_unlock_slowpath);
> > * rsi = lockval (second argument)
> > * rdx = internal variable (set to 0)
> > */
> > -asm (".pushsection .text;"
> > +asm (".pushsection .spinlock.text;"
> > ".globl " PV_UNLOCK ";"
> > ".type " PV_UNLOCK ", @function;"
> > ".align 4,0x90;"
> >
> That is what I meant. However, you should also a comment saying that the
> use of .spinlock.text section is equivalent to the use of __lockfunc on
> an equivalent C function to make it clear. Also add the __lockfunc to
> the pseudo code in the comment section.
Thanks, will add!
Namhyung
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] locking: Add __lockfunc to slow path functions
2022-08-09 23:37 ` Namhyung Kim
@ 2022-08-10 21:00 ` Namhyung Kim
0 siblings, 0 replies; 6+ messages in thread
From: Namhyung Kim @ 2022-08-10 21:00 UTC (permalink / raw)
To: Waiman Long; +Cc: Peter Zijlstra, Ingo Molnar, Will Deacon, Boqun Feng, LKML
On Tue, Aug 9, 2022 at 4:37 PM Namhyung Kim <namhyung@kernel.org> wrote:
>
> On Tue, Aug 9, 2022 at 4:09 PM Waiman Long <longman@redhat.com> wrote:
> >
> > On 8/9/22 17:13, Namhyung Kim wrote:
> > > --- a/arch/x86/include/asm/qspinlock_paravirt.h
> > > +++ b/arch/x86/include/asm/qspinlock_paravirt.h
> > > @@ -36,7 +36,7 @@ PV_CALLEE_SAVE_REGS_THUNK(__pv_queued_spin_unlock_slowpath);
> > > * rsi = lockval (second argument)
> > > * rdx = internal variable (set to 0)
> > > */
> > > -asm (".pushsection .text;"
> > > +asm (".pushsection .spinlock.text;"
> > > ".globl " PV_UNLOCK ";"
> > > ".type " PV_UNLOCK ", @function;"
> > > ".align 4,0x90;"
> > >
> > That is what I meant. However, you should also a comment saying that the
> > use of .spinlock.text section is equivalent to the use of __lockfunc on
> > an equivalent C function to make it clear. Also add the __lockfunc to
> > the pseudo code in the comment section.
FYI I had to use __PV_CALLEE_SAVE_REGS_THUNK to pass the section name
(".spinlock.text") to prevent a build error.
CC kernel/locking/qspinlock.o
/tmp/ccdn2Gyk.s: Assembler messages:
/tmp/ccdn2Gyk.s:725: Error: changed section attributes for .spinlock.text
Thanks,
Namhyung
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2022-08-10 21:01 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2022-08-08 17:59 [PATCH] locking: Add __lockfunc to slow path functions Namhyung Kim
2022-08-09 15:05 ` Waiman Long
2022-08-09 21:13 ` Namhyung Kim
2022-08-09 23:09 ` Waiman Long
2022-08-09 23:37 ` Namhyung Kim
2022-08-10 21:00 ` Namhyung Kim
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