On 3/14/25 13:55, Peter Zijlstra wrote:
On Fri, Mar 14, 2025 at 11:15:42AM +0530, Shrikanth Hegde wrote:
use guard(mutex) for scope based resource management of mutex.
This would make the code simpler and easier to maintain.
More details on lock guards can be found at
https://lore.kernel.org/all/[email protected]/T/#u
There is also an example of using scoped_guard.
Signed-off-by: Shrikanth Hegde
---
arch/powerpc/platforms/book3s/vas-api.c | 19 ++-
1 file changed, 6 insertions(+), 13 deletions(-)
diff --git a/arch/powerpc/platforms/book3s/vas-api.c
b/arch/powerpc/platforms/book3s/vas-api.c
index 0b6365d85d11..eb1a97271afb 100644
--- a/arch/powerpc/platforms/book3s/vas-api.c
+++ b/arch/powerpc/platforms/book3s/vas-api.c
@@ -425,7 +425,7 @@ static vm_fault_t vas_mmap_fault(struct vm_fault *vmf)
return VM_FAULT_SIGBUS;
}
- mutex_lock(&txwin->task_ref.mmap_mutex);
+ guard(mutex)(&txwin->task_ref.mmap_mutex);
/*
* The window may be inactive due to lost credit (Ex: core
* removal with DLPAR). If the window is active again when
@@ -437,11 +437,9 @@ static vm_fault_t vas_mmap_fault(struct vm_fault *vmf)
if (paste_addr) {
fault = vmf_insert_pfn(vma, vma->vm_start,
(paste_addr >> PAGE_SHIFT));
- mutex_unlock(&txwin->task_ref.mmap_mutex);
return fault;
}
}
- mutex_unlock(&txwin->task_ref.mmap_mutex);
I had to open up this file to check, but this seems incorrect since you
now also run do_fail_paste() with the lock held, where previously you
did not.
Yes. Got it. let me use scoped_guard for it as well. There is get_user
and other things in the fail parse and having it with mutex will not be
good.
I went through the rest of the patches too. It is mostly return after
mutex.
Only in Patch 5/6 there is additional debug statement. Let me put a
comment there.
/*
* Received this fault due to closing the actual window.
