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Date: Mon, 8 Apr 2024 10:47:12 -0700
From: Vishal Moola <vishal.moola@gmail.com>
To: Muchun Song <muchun.song@linux.dev>
Cc: linux-kernel@vger.kernel.org, akpm@linux-foundation.org,
	willy@infradead.org, linux-mm@kvack.org
Subject: Re: [PATCH v2 3/3] hugetlb: Convert hugetlb_wp() to use struct
 vm_fault
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References: <20240401202651.31440-1-vishal.moola@gmail.com>
 <20240401202651.31440-4-vishal.moola@gmail.com>
 <7d001108-157d-4139-bfa9-5b4102166f17@linux.dev>
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On Sun, Apr 07, 2024 at 05:12:42PM +0800, Muchun Song wrote:
> 
> 
> On 2024/4/2 04:26, Vishal Moola (Oracle) wrote:
> > hugetlb_wp() can use the struct vm_fault passed in from hugetlb_fault().
> > This alleviates the stack by consolidating 5 variables into a single
> > struct.
> > 
> > Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
> > ---
> >   mm/hugetlb.c | 61 ++++++++++++++++++++++++++--------------------------
> >   1 file changed, 30 insertions(+), 31 deletions(-)
> > 
> > diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> > index aca2f11b4138..d4f26947173e 100644
> > --- a/mm/hugetlb.c
> > +++ b/mm/hugetlb.c
> > @@ -5918,18 +5918,16 @@ static void unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma,
> >    * Keep the pte_same checks anyway to make transition from the mutex easier.
> >    */
> >   static vm_fault_t hugetlb_wp(struct mm_struct *mm, struct vm_area_struct *vma,
> > -		       unsigned long address, pte_t *ptep, unsigned int flags,
> > -		       struct folio *pagecache_folio, spinlock_t *ptl,
> > +		       struct folio *pagecache_folio,
> 
> The same as comment in the previous thread.

And fold the attached patch into here as well please Andrew? 

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From f4adcf13ecc15a6733af43649756e53457078221 Mon Sep 17 00:00:00 2001
From: "Vishal Moola (Oracle)" <vishal.moola@gmail.com>
Date: Mon, 8 Apr 2024 10:21:44 -0700
Subject: [PATCH 2/2] hugetlb: Simplyfy hugetlb_wp() arguments

To simplify the function arguments, as suggested by Oscar and Muchun.

Suggested-by: Muchun Song <muchun.song@linux.dev>
Suggested-by: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
---
 mm/hugetlb.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 05fe610f4699..0d96a41efde8 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -5915,10 +5915,11 @@ static void unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma,
  * cannot race with other handlers or page migration.
  * Keep the pte_same checks anyway to make transition from the mutex easier.
  */
-static vm_fault_t hugetlb_wp(struct mm_struct *mm, struct vm_area_struct *vma,
-		       struct folio *pagecache_folio,
+static vm_fault_t hugetlb_wp(struct folio *pagecache_folio,
 		       struct vm_fault *vmf)
 {
+	struct vm_area_struct *vma = vmf->vma;
+	struct mm_struct *mm = vma->vm_mm;
 	const bool unshare = vmf->flags & FAULT_FLAG_UNSHARE;
 	pte_t pte = huge_ptep_get(vmf->pte);
 	struct hstate *h = hstate_vma(vma);
@@ -6364,7 +6365,7 @@ static vm_fault_t hugetlb_no_page(struct address_space *mapping,
 	hugetlb_count_add(pages_per_huge_page(h), mm);
 	if ((vmf->flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) {
 		/* Optimization, do the COW without a second fault */
-		ret = hugetlb_wp(mm, vma, folio, vmf);
+		ret = hugetlb_wp(folio, vmf);
 	}
 
 	spin_unlock(vmf->ptl);
@@ -6577,7 +6578,7 @@ vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
 
 	if (flags & (FAULT_FLAG_WRITE|FAULT_FLAG_UNSHARE)) {
 		if (!huge_pte_write(vmf.orig_pte)) {
-			ret = hugetlb_wp(mm, vma, pagecache_folio, &vmf);
+			ret = hugetlb_wp(pagecache_folio, &vmf);
 			goto out_put_page;
 		} else if (likely(flags & FAULT_FLAG_WRITE)) {
 			vmf.orig_pte = huge_pte_mkdirty(vmf.orig_pte);
-- 
2.43.0


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