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[PATCH] rust: sync: optimize rust symbol generation for CondVar

Kunwu Chan posted 1 patch 9 months ago
There is a newer version of this series
rust/kernel/sync/condvar.rs | 4 ++++
1 file changed, 4 insertions(+)
[PATCH] rust: sync: optimize rust symbol generation for CondVar
Posted by Kunwu Chan 9 months ago 
From: Kunwu Chan <kunwu.chan@hotmail.com>

When build the kernel using the llvm-18.1.3-rust-1.85.0-x86_64
with ARCH=arm64, the following symbols are generated:

$nm vmlinux | grep ' _R'.*CondVar | rustfilt
... T <kernel::sync::condvar::CondVar>::notify_all
... T <kernel::sync::condvar::CondVar>::notify_one
... T <kernel::sync::condvar::CondVar>::notify_sync
... T <kernel::sync::condvar::CondVar>::new::{closure#0}::{closure#0}::panic_cold_explicit
... T <kernel::sync::condvar::CondVar>::new::{closure#0}::{closure#0}::panic_cold_explicit
... T <kernel::sync::poll::PollCondVar>::new::{closure#0}::{closure#0}::panic_cold_explicit
... T <kernel::sync::poll::PollCondVar as core::ops::drop::Drop>::drop

These notify* symbols are trivial wrappers around the C functions
__wake_up and __wake_up_sync.
It doesn't make sense to go through a trivial wrapper for these
functions, so mark them inline.

Link: https://github.com/Rust-for-Linux/linux/issues/1145
Suggested-by: Alice Ryhl <aliceryhl@google.com>
Co-developed-by: Grace Deng <Grace.Deng006@Gmail.com>
Signed-off-by: Grace Deng <Grace.Deng006@Gmail.com>
Signed-off-by: Kunwu Chan <kunwu.chan@hotmail.com>
---
 rust/kernel/sync/condvar.rs | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/rust/kernel/sync/condvar.rs b/rust/kernel/sync/condvar.rs
index 7df565038d7d..a826896ba3f0 100644
--- a/rust/kernel/sync/condvar.rs
+++ b/rust/kernel/sync/condvar.rs
@@ -181,6 +181,7 @@ pub fn wait_interruptible_timeout<T: ?Sized, B: Backend>(
     }
 
     /// Calls the kernel function to notify the appropriate number of threads.
+    #[inline]
     fn notify(&self, count: c_int) {
         // SAFETY: `wait_queue_head` points to valid memory.
         unsafe {
@@ -198,6 +199,7 @@ fn notify(&self, count: c_int) {
     /// This method behaves like `notify_one`, except that it hints to the scheduler that the
     /// current thread is about to go to sleep, so it should schedule the target thread on the same
     /// CPU.
+    #[inline]
     pub fn notify_sync(&self) {
         // SAFETY: `wait_queue_head` points to valid memory.
         unsafe { bindings::__wake_up_sync(self.wait_queue_head.get(), TASK_NORMAL) };
@@ -207,6 +209,7 @@ pub fn notify_sync(&self) {
     ///
     /// This is not 'sticky' in the sense that if no thread is waiting, the notification is lost
     /// completely (as opposed to automatically waking up the next waiter).
+    #[inline]
     pub fn notify_one(&self) {
         self.notify(1);
     }
@@ -215,6 +218,7 @@ pub fn notify_one(&self) {
     ///
     /// This is not 'sticky' in the sense that if no thread is waiting, the notification is lost
     /// completely (as opposed to automatically waking up the next waiter).
+    #[inline]
     pub fn notify_all(&self) {
         self.notify(0);
     }
-- 
2.43.0
Re: [PATCH] rust: sync: optimize rust symbol generation for CondVar
Posted by Boqun Feng 8 months, 4 weeks ago 
On Mon, Mar 17, 2025 at 04:13:50PM +0800, Kunwu Chan wrote:
> From: Kunwu Chan <kunwu.chan@hotmail.com>
> 
> When build the kernel using the llvm-18.1.3-rust-1.85.0-x86_64
> with ARCH=arm64, the following symbols are generated:
> 
> $nm vmlinux | grep ' _R'.*CondVar | rustfilt
> ... T <kernel::sync::condvar::CondVar>::notify_all
> ... T <kernel::sync::condvar::CondVar>::notify_one
> ... T <kernel::sync::condvar::CondVar>::notify_sync
> ... T <kernel::sync::condvar::CondVar>::new::{closure#0}::{closure#0}::panic_cold_explicit
> ... T <kernel::sync::condvar::CondVar>::new::{closure#0}::{closure#0}::panic_cold_explicit
> ... T <kernel::sync::poll::PollCondVar>::new::{closure#0}::{closure#0}::panic_cold_explicit
> ... T <kernel::sync::poll::PollCondVar as core::ops::drop::Drop>::drop
> 
> These notify* symbols are trivial wrappers around the C functions
> __wake_up and __wake_up_sync.
> It doesn't make sense to go through a trivial wrapper for these
> functions, so mark them inline.
> 
> Link: https://github.com/Rust-for-Linux/linux/issues/1145
> Suggested-by: Alice Ryhl <aliceryhl@google.com>
> Co-developed-by: Grace Deng <Grace.Deng006@Gmail.com>
> Signed-off-by: Grace Deng <Grace.Deng006@Gmail.com>
> Signed-off-by: Kunwu Chan <kunwu.chan@hotmail.com>
> ---
>  rust/kernel/sync/condvar.rs | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/rust/kernel/sync/condvar.rs b/rust/kernel/sync/condvar.rs
> index 7df565038d7d..a826896ba3f0 100644
> --- a/rust/kernel/sync/condvar.rs
> +++ b/rust/kernel/sync/condvar.rs
> @@ -181,6 +181,7 @@ pub fn wait_interruptible_timeout<T: ?Sized, B: Backend>(
>      }
>  
>      /// Calls the kernel function to notify the appropriate number of threads.
> +    #[inline]
>      fn notify(&self, count: c_int) {

Hmm.. I think CondVar::notify() gets inlined even without this
`#[inline]` attribute, do we need this actually?

Regards,
Boqun

>          // SAFETY: `wait_queue_head` points to valid memory.
>          unsafe {
[...]
Re: [PATCH] rust: sync: optimize rust symbol generation for CondVar
Posted by Kunwu Chan 8 months, 4 weeks ago 
On 2025/3/24 01:59, Boqun Feng wrote:
> On Mon, Mar 17, 2025 at 04:13:50PM +0800, Kunwu Chan wrote:
>> From: Kunwu Chan <kunwu.chan@hotmail.com>
>>
>> When build the kernel using the llvm-18.1.3-rust-1.85.0-x86_64
>> with ARCH=arm64, the following symbols are generated:
>>
>> $nm vmlinux | grep ' _R'.*CondVar | rustfilt
>> ... T <kernel::sync::condvar::CondVar>::notify_all
>> ... T <kernel::sync::condvar::CondVar>::notify_one
>> ... T <kernel::sync::condvar::CondVar>::notify_sync
>> ... T <kernel::sync::condvar::CondVar>::new::{closure#0}::{closure#0}::panic_cold_explicit
>> ... T <kernel::sync::condvar::CondVar>::new::{closure#0}::{closure#0}::panic_cold_explicit
>> ... T <kernel::sync::poll::PollCondVar>::new::{closure#0}::{closure#0}::panic_cold_explicit
>> ... T <kernel::sync::poll::PollCondVar as core::ops::drop::Drop>::drop
>>
>> These notify* symbols are trivial wrappers around the C functions
>> __wake_up and __wake_up_sync.
>> It doesn't make sense to go through a trivial wrapper for these
>> functions, so mark them inline.
>>
>> Link: https://github.com/Rust-for-Linux/linux/issues/1145
>> Suggested-by: Alice Ryhl <aliceryhl@google.com>
>> Co-developed-by: Grace Deng <Grace.Deng006@Gmail.com>
>> Signed-off-by: Grace Deng <Grace.Deng006@Gmail.com>
>> Signed-off-by: Kunwu Chan <kunwu.chan@hotmail.com>
>> ---
>>   rust/kernel/sync/condvar.rs | 4 ++++
>>   1 file changed, 4 insertions(+)
>>
>> diff --git a/rust/kernel/sync/condvar.rs b/rust/kernel/sync/condvar.rs
>> index 7df565038d7d..a826896ba3f0 100644
>> --- a/rust/kernel/sync/condvar.rs
>> +++ b/rust/kernel/sync/condvar.rs
>> @@ -181,6 +181,7 @@ pub fn wait_interruptible_timeout<T: ?Sized, B: Backend>(
>>       }
>>   
>>       /// Calls the kernel function to notify the appropriate number of threads.
>> +    #[inline]
>>       fn notify(&self, count: c_int) {
> Hmm.. I think CondVar::notify() gets inlined even without this
> `#[inline]` attribute, do we need this actually?

Actualy, after add '#[inline]', the build result is (compilecmd is 'make 
ARCH=arm64 LLVM=1-j8' ):

$nm vmlinux | grep ' _R'.*CondVar | rustfilt
ffff800080019e90 T 
<kernel::sync::condvar::CondVar>::new::{closure#0}::{closure#0}::panic_cold_ex
plicit
ffff800080019e90 T 
<kernel::sync::condvar::CondVar>::new::{closure#0}::{closure#0}::panic_cold_ex
plicit
ffff800080019e90 T 
<kernel::sync::poll::PollCondVar>::new::{closure#0}::{closure#0}::panic_cold_e
xplicit
ffff8000805b8c7c T <kernel::sync::poll::PollCondVar as 
core::ops::drop::Drop>::drop


And before add '#[inline]',the 'nm vmlinux | grep ' _R'.*CondVar | 
rustfilt' appear 'notify' function,

Seems like the LLVM didn't make it inline.


> Regards,
> Boqun
>
>>           // SAFETY: `wait_queue_head` points to valid memory.
>>           unsafe {
> [...]

-- 
Thanks,
   Kunwu.Chan(Tao.Chan)
Re: [PATCH] rust: sync: optimize rust symbol generation for CondVar
Posted by Boqun Feng 8 months, 4 weeks ago 
On Mon, Mar 24, 2025 at 10:08:29AM +0800, Kunwu Chan wrote:
> On 2025/3/24 01:59, Boqun Feng wrote:
> > On Mon, Mar 17, 2025 at 04:13:50PM +0800, Kunwu Chan wrote:
> > > From: Kunwu Chan <kunwu.chan@hotmail.com>
> > > 
> > > When build the kernel using the llvm-18.1.3-rust-1.85.0-x86_64
> > > with ARCH=arm64, the following symbols are generated:
> > > 
> > > $nm vmlinux | grep ' _R'.*CondVar | rustfilt
> > > ... T <kernel::sync::condvar::CondVar>::notify_all
> > > ... T <kernel::sync::condvar::CondVar>::notify_one
> > > ... T <kernel::sync::condvar::CondVar>::notify_sync
> > > ... T <kernel::sync::condvar::CondVar>::new::{closure#0}::{closure#0}::panic_cold_explicit
> > > ... T <kernel::sync::condvar::CondVar>::new::{closure#0}::{closure#0}::panic_cold_explicit
> > > ... T <kernel::sync::poll::PollCondVar>::new::{closure#0}::{closure#0}::panic_cold_explicit
> > > ... T <kernel::sync::poll::PollCondVar as core::ops::drop::Drop>::drop
> > > 
> > > These notify* symbols are trivial wrappers around the C functions
> > > __wake_up and __wake_up_sync.
> > > It doesn't make sense to go through a trivial wrapper for these
> > > functions, so mark them inline.
> > > 
> > > Link: https://github.com/Rust-for-Linux/linux/issues/1145
> > > Suggested-by: Alice Ryhl <aliceryhl@google.com>
> > > Co-developed-by: Grace Deng <Grace.Deng006@Gmail.com>
> > > Signed-off-by: Grace Deng <Grace.Deng006@Gmail.com>
> > > Signed-off-by: Kunwu Chan <kunwu.chan@hotmail.com>
> > > ---
> > >   rust/kernel/sync/condvar.rs | 4 ++++
> > >   1 file changed, 4 insertions(+)
> > > 
> > > diff --git a/rust/kernel/sync/condvar.rs b/rust/kernel/sync/condvar.rs
> > > index 7df565038d7d..a826896ba3f0 100644
> > > --- a/rust/kernel/sync/condvar.rs
> > > +++ b/rust/kernel/sync/condvar.rs
> > > @@ -181,6 +181,7 @@ pub fn wait_interruptible_timeout<T: ?Sized, B: Backend>(
> > >       }
> > >       /// Calls the kernel function to notify the appropriate number of threads.
> > > +    #[inline]
> > >       fn notify(&self, count: c_int) {
> > Hmm.. I think CondVar::notify() gets inlined even without this
> > `#[inline]` attribute, do we need this actually?
> 
> Actualy, after add '#[inline]', the build result is (compilecmd is 'make
> ARCH=arm64 LLVM=1-j8' ):
> 
> $nm vmlinux | grep ' _R'.*CondVar | rustfilt
> ffff800080019e90 T <kernel::sync::condvar::CondVar>::new::{closure#0}::{closure#0}::panic_cold_ex
> plicit
> ffff800080019e90 T <kernel::sync::condvar::CondVar>::new::{closure#0}::{closure#0}::panic_cold_ex
> plicit
> ffff800080019e90 T <kernel::sync::poll::PollCondVar>::new::{closure#0}::{closure#0}::panic_cold_e
> xplicit
> ffff8000805b8c7c T <kernel::sync::poll::PollCondVar as
> core::ops::drop::Drop>::drop
> 
> 
> And before add '#[inline]',the 'nm vmlinux | grep ' _R'.*CondVar | rustfilt'
> appear 'notify' function,
> 
> Seems like the LLVM didn't make it inline.
> 

Your commit log said:

... the following symbols are generated:

$nm vmlinux | grep ' _R'.*CondVar | rustfilt
... T <kernel::sync::condvar::CondVar>::notify_all
... T <kernel::sync::condvar::CondVar>::notify_one
... T <kernel::sync::condvar::CondVar>::notify_sync
... T <kernel::sync::condvar::CondVar>::new::{closure#0}::{closure#0}::panic_cold_explicit
... T <kernel::sync::condvar::CondVar>::new::{closure#0}::{closure#0}::panic_cold_explicit
... T <kernel::sync::poll::PollCondVar>::new::{closure#0}::{closure#0}::panic_cold_explicit
... T <kernel::sync::poll::PollCondVar as core::ops::drop::Drop>::drop

so no *notify* symbol even before the patch, right? I also checked with
my local build, without your patch, there is still no symbol for
notify().

Regards,
Boqun
Re: [PATCH] rust: sync: optimize rust symbol generation for CondVar
Posted by Kunwu Chan 8 months, 4 weeks ago 
On 2025/3/24 12:23, Boqun Feng wrote:
> On Mon, Mar 24, 2025 at 10:08:29AM +0800, Kunwu Chan wrote:
>> On 2025/3/24 01:59, Boqun Feng wrote:
>>> On Mon, Mar 17, 2025 at 04:13:50PM +0800, Kunwu Chan wrote:
>>>> From: Kunwu Chan <kunwu.chan@hotmail.com>
>>>>
>>>> When build the kernel using the llvm-18.1.3-rust-1.85.0-x86_64
>>>> with ARCH=arm64, the following symbols are generated:
>>>>
>>>> $nm vmlinux | grep ' _R'.*CondVar | rustfilt
>>>> ... T <kernel::sync::condvar::CondVar>::notify_all
>>>> ... T <kernel::sync::condvar::CondVar>::notify_one
>>>> ... T <kernel::sync::condvar::CondVar>::notify_sync
>>>> ... T <kernel::sync::condvar::CondVar>::new::{closure#0}::{closure#0}::panic_cold_explicit
>>>> ... T <kernel::sync::condvar::CondVar>::new::{closure#0}::{closure#0}::panic_cold_explicit
>>>> ... T <kernel::sync::poll::PollCondVar>::new::{closure#0}::{closure#0}::panic_cold_explicit
>>>> ... T <kernel::sync::poll::PollCondVar as core::ops::drop::Drop>::drop
>>>>
>>>> These notify* symbols are trivial wrappers around the C functions
>>>> __wake_up and __wake_up_sync.
>>>> It doesn't make sense to go through a trivial wrapper for these
>>>> functions, so mark them inline.
>>>>
>>>> Link: https://github.com/Rust-for-Linux/linux/issues/1145
>>>> Suggested-by: Alice Ryhl <aliceryhl@google.com>
>>>> Co-developed-by: Grace Deng <Grace.Deng006@Gmail.com>
>>>> Signed-off-by: Grace Deng <Grace.Deng006@Gmail.com>
>>>> Signed-off-by: Kunwu Chan <kunwu.chan@hotmail.com>
>>>> ---
>>>>    rust/kernel/sync/condvar.rs | 4 ++++
>>>>    1 file changed, 4 insertions(+)
>>>>
>>>> diff --git a/rust/kernel/sync/condvar.rs b/rust/kernel/sync/condvar.rs
>>>> index 7df565038d7d..a826896ba3f0 100644
>>>> --- a/rust/kernel/sync/condvar.rs
>>>> +++ b/rust/kernel/sync/condvar.rs
>>>> @@ -181,6 +181,7 @@ pub fn wait_interruptible_timeout<T: ?Sized, B: Backend>(
>>>>        }
>>>>        /// Calls the kernel function to notify the appropriate number of threads.
>>>> +    #[inline]
>>>>        fn notify(&self, count: c_int) {
>>> Hmm.. I think CondVar::notify() gets inlined even without this
>>> `#[inline]` attribute, do we need this actually?
>> Actualy, after add '#[inline]', the build result is (compilecmd is 'make
>> ARCH=arm64 LLVM=1-j8' ):
>>
>> $nm vmlinux | grep ' _R'.*CondVar | rustfilt
>> ffff800080019e90 T <kernel::sync::condvar::CondVar>::new::{closure#0}::{closure#0}::panic_cold_ex
>> plicit
>> ffff800080019e90 T <kernel::sync::condvar::CondVar>::new::{closure#0}::{closure#0}::panic_cold_ex
>> plicit
>> ffff800080019e90 T <kernel::sync::poll::PollCondVar>::new::{closure#0}::{closure#0}::panic_cold_e
>> xplicit
>> ffff8000805b8c7c T <kernel::sync::poll::PollCondVar as
>> core::ops::drop::Drop>::drop
>>
>>
>> And before add '#[inline]',the 'nm vmlinux | grep ' _R'.*CondVar | rustfilt'
>> appear 'notify' function,
>>
>> Seems like the LLVM didn't make it inline.
>>
> Your commit log said:
>
> ... the following symbols are generated:
>
> $nm vmlinux | grep ' _R'.*CondVar | rustfilt
> ... T <kernel::sync::condvar::CondVar>::notify_all
> ... T <kernel::sync::condvar::CondVar>::notify_one
> ... T <kernel::sync::condvar::CondVar>::notify_sync
> ... T <kernel::sync::condvar::CondVar>::new::{closure#0}::{closure#0}::panic_cold_explicit
> ... T <kernel::sync::condvar::CondVar>::new::{closure#0}::{closure#0}::panic_cold_explicit
> ... T <kernel::sync::poll::PollCondVar>::new::{closure#0}::{closure#0}::panic_cold_explicit
> ... T <kernel::sync::poll::PollCondVar as core::ops::drop::Drop>::drop
>
> so no *notify* symbol even before the patch, right? I also checked with

My bad,I mistakenly thought it was some other 'notify_*' functions,

it should be LLVM automatically inline 'notify', I will remove it in the 
next version.

> my local build, without your patch, there is still no symbol for
> notify().
>
> Regards,
> Boqun

-- 
Thanks,
   Kunwu.Chan(Tao.Chan)
Re: [PATCH] rust: sync: optimize rust symbol generation for CondVar
Posted by Alice Ryhl 9 months ago 
On Mon, Mar 17, 2025 at 04:13:50PM +0800, Kunwu Chan wrote:
> From: Kunwu Chan <kunwu.chan@hotmail.com>
> 
> When build the kernel using the llvm-18.1.3-rust-1.85.0-x86_64
> with ARCH=arm64, the following symbols are generated:
> 
> $nm vmlinux | grep ' _R'.*CondVar | rustfilt
> ... T <kernel::sync::condvar::CondVar>::notify_all
> ... T <kernel::sync::condvar::CondVar>::notify_one
> ... T <kernel::sync::condvar::CondVar>::notify_sync
> ... T <kernel::sync::condvar::CondVar>::new::{closure#0}::{closure#0}::panic_cold_explicit
> ... T <kernel::sync::condvar::CondVar>::new::{closure#0}::{closure#0}::panic_cold_explicit
> ... T <kernel::sync::poll::PollCondVar>::new::{closure#0}::{closure#0}::panic_cold_explicit
> ... T <kernel::sync::poll::PollCondVar as core::ops::drop::Drop>::drop
> 
> These notify* symbols are trivial wrappers around the C functions
> __wake_up and __wake_up_sync.
> It doesn't make sense to go through a trivial wrapper for these
> functions, so mark them inline.

You don't need to send a new version just for this, but please format
the paragraphs better in the future. For example:

The notify* symbols are trivial wrappers around the C functions
__wake_up and __wake_up_sync. It doesn't make sense to go through a
trivial wrapper for these functions, so mark them inline.

> Link: https://github.com/Rust-for-Linux/linux/issues/1145
> Suggested-by: Alice Ryhl <aliceryhl@google.com>
> Co-developed-by: Grace Deng <Grace.Deng006@Gmail.com>
> Signed-off-by: Grace Deng <Grace.Deng006@Gmail.com>
> Signed-off-by: Kunwu Chan <kunwu.chan@hotmail.com>

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Re: [PATCH] rust: sync: optimize rust symbol generation for CondVar
Posted by Boqun Feng 8 months, 4 weeks ago 
On Mon, Mar 17, 2025 at 10:29:17AM +0000, Alice Ryhl wrote:
> On Mon, Mar 17, 2025 at 04:13:50PM +0800, Kunwu Chan wrote:
> > From: Kunwu Chan <kunwu.chan@hotmail.com>
> > 
> > When build the kernel using the llvm-18.1.3-rust-1.85.0-x86_64
> > with ARCH=arm64, the following symbols are generated:
> > 
> > $nm vmlinux | grep ' _R'.*CondVar | rustfilt
> > ... T <kernel::sync::condvar::CondVar>::notify_all
> > ... T <kernel::sync::condvar::CondVar>::notify_one
> > ... T <kernel::sync::condvar::CondVar>::notify_sync
> > ... T <kernel::sync::condvar::CondVar>::new::{closure#0}::{closure#0}::panic_cold_explicit
> > ... T <kernel::sync::condvar::CondVar>::new::{closure#0}::{closure#0}::panic_cold_explicit
> > ... T <kernel::sync::poll::PollCondVar>::new::{closure#0}::{closure#0}::panic_cold_explicit
> > ... T <kernel::sync::poll::PollCondVar as core::ops::drop::Drop>::drop
> > 
> > These notify* symbols are trivial wrappers around the C functions
> > __wake_up and __wake_up_sync.
> > It doesn't make sense to go through a trivial wrapper for these
> > functions, so mark them inline.
> 
> You don't need to send a new version just for this, but please format
> the paragraphs better in the future. For example:
> 
> The notify* symbols are trivial wrappers around the C functions
> __wake_up and __wake_up_sync. It doesn't make sense to go through a
> trivial wrapper for these functions, so mark them inline.
> 
> > Link: https://github.com/Rust-for-Linux/linux/issues/1145
> > Suggested-by: Alice Ryhl <aliceryhl@google.com>
> > Co-developed-by: Grace Deng <Grace.Deng006@Gmail.com>
> > Signed-off-by: Grace Deng <Grace.Deng006@Gmail.com>
> > Signed-off-by: Kunwu Chan <kunwu.chan@hotmail.com>
> 
> Reviewed-by: Alice Ryhl <aliceryhl@google.com>
> 

Queued for future tests and reviews, thank you all.

Regards,
Boqun
Re: [PATCH] rust: sync: optimize rust symbol generation for CondVar
Posted by Kunwu Chan 9 months ago 
On 2025/3/17 18:29, Alice Ryhl wrote:
> On Mon, Mar 17, 2025 at 04:13:50PM +0800, Kunwu Chan wrote:
>> From: Kunwu Chan <kunwu.chan@hotmail.com>
>>
>> When build the kernel using the llvm-18.1.3-rust-1.85.0-x86_64
>> with ARCH=arm64, the following symbols are generated:
>>
>> $nm vmlinux | grep ' _R'.*CondVar | rustfilt
>> ... T <kernel::sync::condvar::CondVar>::notify_all
>> ... T <kernel::sync::condvar::CondVar>::notify_one
>> ... T <kernel::sync::condvar::CondVar>::notify_sync
>> ... T <kernel::sync::condvar::CondVar>::new::{closure#0}::{closure#0}::panic_cold_explicit
>> ... T <kernel::sync::condvar::CondVar>::new::{closure#0}::{closure#0}::panic_cold_explicit
>> ... T <kernel::sync::poll::PollCondVar>::new::{closure#0}::{closure#0}::panic_cold_explicit
>> ... T <kernel::sync::poll::PollCondVar as core::ops::drop::Drop>::drop
>>
>> These notify* symbols are trivial wrappers around the C functions
>> __wake_up and __wake_up_sync.
>> It doesn't make sense to go through a trivial wrapper for these
>> functions, so mark them inline.
> You don't need to send a new version just for this, but please format
> the paragraphs better in the future. For example:
>
> The notify* symbols are trivial wrappers around the C functions
> __wake_up and __wake_up_sync. It doesn't make sense to go through a
> trivial wrapper for these functions, so mark them inline.

Thanks, I'll remember that, try to fill one line first and don't start a 
new one easily.

>> Link: https://github.com/Rust-for-Linux/linux/issues/1145
>> Suggested-by: Alice Ryhl <aliceryhl@google.com>
>> Co-developed-by: Grace Deng <Grace.Deng006@Gmail.com>
>> Signed-off-by: Grace Deng <Grace.Deng006@Gmail.com>
>> Signed-off-by: Kunwu Chan <kunwu.chan@hotmail.com>
> Reviewed-by: Alice Ryhl <aliceryhl@google.com>
>
-- 
Thanks,
   Kunwu.Chan
Re: [PATCH] rust: sync: optimize rust symbol generation for CondVar
Posted by Benno Lossin 9 months ago 
On Mon Mar 17, 2025 at 9:13 AM CET, Kunwu Chan wrote:
> From: Kunwu Chan <kunwu.chan@hotmail.com>
>
> When build the kernel using the llvm-18.1.3-rust-1.85.0-x86_64
> with ARCH=arm64, the following symbols are generated:
>
> $nm vmlinux | grep ' _R'.*CondVar | rustfilt
> ... T <kernel::sync::condvar::CondVar>::notify_all
> ... T <kernel::sync::condvar::CondVar>::notify_one
> ... T <kernel::sync::condvar::CondVar>::notify_sync
> ... T <kernel::sync::condvar::CondVar>::new::{closure#0}::{closure#0}::panic_cold_explicit
> ... T <kernel::sync::condvar::CondVar>::new::{closure#0}::{closure#0}::panic_cold_explicit
> ... T <kernel::sync::poll::PollCondVar>::new::{closure#0}::{closure#0}::panic_cold_explicit
> ... T <kernel::sync::poll::PollCondVar as core::ops::drop::Drop>::drop
>
> These notify* symbols are trivial wrappers around the C functions
> __wake_up and __wake_up_sync.
> It doesn't make sense to go through a trivial wrapper for these
> functions, so mark them inline.
>
> Link: https://github.com/Rust-for-Linux/linux/issues/1145
> Suggested-by: Alice Ryhl <aliceryhl@google.com>
> Co-developed-by: Grace Deng <Grace.Deng006@Gmail.com>
> Signed-off-by: Grace Deng <Grace.Deng006@Gmail.com>
> Signed-off-by: Kunwu Chan <kunwu.chan@hotmail.com>

Reviewed-by: Benno Lossin <benno.lossin@proton.me>

---
Cheers,
Benno

> ---
>  rust/kernel/sync/condvar.rs | 4 ++++
>  1 file changed, 4 insertions(+)

Patchew 2.1-devel-b67e4c2

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