[PATCH v4 07/26] mm/hexagon: Use general page fault accounting

[PATCH v4 07/26] mm/hexagon: Use general page fault accounting

[Peter Xu]

Use the general page fault accounting by passing regs into handle_mm_fault().
It naturally solve the issue of multiple page fault accounting when page fault
retry happened.

Add the missing PERF_COUNT_SW_PAGE_FAULTS perf events too.  Note, the other two
perf events (PERF_COUNT_SW_PAGE_FAULTS_[MAJ|MIN]) were done in handle_mm_fault().

CC: Brian Cain <bcain@codeaurora.org>
CC: linux-hexagon@vger.kernel.org
Signed-off-by: Peter Xu <peterx@redhat.com>
---
 arch/hexagon/mm/vm_fault.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/arch/hexagon/mm/vm_fault.c b/arch/hexagon/mm/vm_fault.c
index f12f330e7946..ef32c5a84ff3 100644
--- a/arch/hexagon/mm/vm_fault.c
+++ b/arch/hexagon/mm/vm_fault.c
@@ -18,6 +18,7 @@
 #include <linux/signal.h>
 #include <linux/extable.h>
 #include <linux/hardirq.h>
+#include <linux/perf_event.h>
 
 /*
  * Decode of hardware exception sends us to one of several
@@ -53,6 +54,8 @@ void do_page_fault(unsigned long address, long cause, struct pt_regs *regs)
 
 	if (user_mode(regs))
 		flags |= FAULT_FLAG_USER;
+
+	perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
 retry:
 	mmap_read_lock(mm);
 	vma = find_vma(mm, address);
@@ -88,7 +91,7 @@ void do_page_fault(unsigned long address, long cause, struct pt_regs *regs)
 		break;
 	}
 
-	fault = handle_mm_fault(vma, address, flags, NULL);
+	fault = handle_mm_fault(vma, address, flags, regs);
 
 	if (fault_signal_pending(fault, regs))
 		return;
@@ -96,10 +99,6 @@ void do_page_fault(unsigned long address, long cause, struct pt_regs *regs)
 	/* The most common case -- we are done. */
 	if (likely(!(fault & VM_FAULT_ERROR))) {
 		if (flags & FAULT_FLAG_ALLOW_RETRY) {
-			if (fault & VM_FAULT_MAJOR)
-				current->maj_flt++;
-			else
-				current->min_flt++;
 			if (fault & VM_FAULT_RETRY) {
 				flags |= FAULT_FLAG_TRIED;
 				goto retry;
-- 
2.26.2

RE: [PATCH v4 07/26] mm/hexagon: Use general page fault accounting

[Brian Cain]

> -----Original Message-----
> From: linux-hexagon-owner@vger.kernel.org <linux-hexagon-
...

Acked-by: Brian Cain <bcain@codeaurora.org>

> CC: Brian Cain <bcain@codeaurora.org>
> CC: linux-hexagon@vger.kernel.org
> Signed-off-by: Peter Xu <peterx@redhat.com>
> ---
>  arch/hexagon/mm/vm_fault.c | 9 ++++-----
>  1 file changed, 4 insertions(+), 5 deletions(-)
> 
> diff --git a/arch/hexagon/mm/vm_fault.c b/arch/hexagon/mm/vm_fault.c
> index f12f330e7946..ef32c5a84ff3 100644
> --- a/arch/hexagon/mm/vm_fault.c
> +++ b/arch/hexagon/mm/vm_fault.c
> @@ -18,6 +18,7 @@
>  #include <linux/signal.h>
>  #include <linux/extable.h>
>  #include <linux/hardirq.h>
> +#include <linux/perf_event.h>
> 
>  /*
>   * Decode of hardware exception sends us to one of several @@ -53,6 +54,8
> @@ void do_page_fault(unsigned long address, long cause, struct pt_regs
> *regs)
> 
>  	if (user_mode(regs))
>  		flags |= FAULT_FLAG_USER;
> +
> +	perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
>  retry:
>  	mmap_read_lock(mm);
>  	vma = find_vma(mm, address);
> @@ -88,7 +91,7 @@ void do_page_fault(unsigned long address, long cause,
> struct pt_regs *regs)
>  		break;
>  	}
> 
> -	fault = handle_mm_fault(vma, address, flags, NULL);
> +	fault = handle_mm_fault(vma, address, flags, regs);
> 
>  	if (fault_signal_pending(fault, regs))
>  		return;
> @@ -96,10 +99,6 @@ void do_page_fault(unsigned long address, long cause,
> struct pt_regs *regs)
>  	/* The most common case -- we are done. */
>  	if (likely(!(fault & VM_FAULT_ERROR))) {
>  		if (flags & FAULT_FLAG_ALLOW_RETRY) {
> -			if (fault & VM_FAULT_MAJOR)
> -				current->maj_flt++;
> -			else
> -				current->min_flt++;
>  			if (fault & VM_FAULT_RETRY) {
>  				flags |= FAULT_FLAG_TRIED;
>  				goto retry;
> --
> 2.26.2