| Message ID | 20211201142918.921493-9-Liam.Howlett@oracle.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Introducing the Maple Tree | expand |
On 12/1/21 15:29, Liam Howlett wrote: > From: "Matthew Wilcox (Oracle)" <willy@infradead.org> > > This simplifies the implementation and is faster than using the linked > list. You mean faster because more cache friendly? OTOH you do max(addr, vma->vm_start) which wasn't the case. I doubt it matters though and yeah it's much simpler... > Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Btw, no signed-off-by Liam? I now also notice some other patches (e.g. patch 4) have From: and s-o-b by Liam followed by Matthew, despite it's Liam sending them. I guess that's less of an issue than the missing one. Anyway something for you to check and make consistent in the whole series, I won't point it out individually. > --- > mm/mmap.c | 24 +++++++----------------- > 1 file changed, 7 insertions(+), 17 deletions(-) > > diff --git a/mm/mmap.c b/mm/mmap.c > index 9fee6e6b276f..de78fc0ce809 100644 > --- a/mm/mmap.c > +++ b/mm/mmap.c > @@ -669,29 +669,19 @@ munmap_vma_range(struct mm_struct *mm, unsigned long start, unsigned long len, > > return 0; > } > + > static unsigned long count_vma_pages_range(struct mm_struct *mm, > unsigned long addr, unsigned long end) > { > - unsigned long nr_pages = 0; > + VMA_ITERATOR(vmi, mm, addr); > struct vm_area_struct *vma; > + unsigned long nr_pages = 0; > > - /* Find first overlapping mapping */ > - vma = find_vma_intersection(mm, addr, end); > - if (!vma) > - return 0; > - > - nr_pages = (min(end, vma->vm_end) - > - max(addr, vma->vm_start)) >> PAGE_SHIFT; > - > - /* Iterate over the rest of the overlaps */ > - for (vma = vma->vm_next; vma; vma = vma->vm_next) { > - unsigned long overlap_len; > - > - if (vma->vm_start > end) > - break; > + for_each_vma_range(vmi, vma, end) { > + unsigned long vm_start = max(addr, vma->vm_start); > + unsigned long vm_end = min(end, vma->vm_end); > > - overlap_len = min(end, vma->vm_end) - vma->vm_start; > - nr_pages += overlap_len >> PAGE_SHIFT; > + nr_pages += (vm_end - vm_start) / PAGE_SIZE; > } > > return nr_pages;
* Vlastimil Babka <vbabka@suse.cz> [211209 10:54]: > On 12/1/21 15:29, Liam Howlett wrote: > > From: "Matthew Wilcox (Oracle)" <willy@infradead.org> > > > > This simplifies the implementation and is faster than using the linked > > list. > > You mean faster because more cache friendly? > OTOH you do max(addr, vma->vm_start) which wasn't the case. > > I doubt it matters though and yeah it's much simpler... > > > Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> > Acked-by: Vlastimil Babka <vbabka@suse.cz> > > Btw, no signed-off-by Liam? > > I now also notice some other patches (e.g. patch 4) have From: and s-o-b by > Liam followed by Matthew, despite it's Liam sending them. I guess that's > less of an issue than the missing one. > > Anyway something for you to check and make consistent in the whole series, I > won't point it out individually. Thanks for catching this. I will clean up the s-o-b for the next revision. > > > --- > > mm/mmap.c | 24 +++++++----------------- > > 1 file changed, 7 insertions(+), 17 deletions(-) > > > > diff --git a/mm/mmap.c b/mm/mmap.c > > index 9fee6e6b276f..de78fc0ce809 100644 > > --- a/mm/mmap.c > > +++ b/mm/mmap.c > > @@ -669,29 +669,19 @@ munmap_vma_range(struct mm_struct *mm, unsigned long start, unsigned long len, > > > > return 0; > > } > > + > > static unsigned long count_vma_pages_range(struct mm_struct *mm, > > unsigned long addr, unsigned long end) > > { > > - unsigned long nr_pages = 0; > > + VMA_ITERATOR(vmi, mm, addr); > > struct vm_area_struct *vma; > > + unsigned long nr_pages = 0; > > > > - /* Find first overlapping mapping */ > > - vma = find_vma_intersection(mm, addr, end); > > - if (!vma) > > - return 0; > > - > > - nr_pages = (min(end, vma->vm_end) - > > - max(addr, vma->vm_start)) >> PAGE_SHIFT; > > - > > - /* Iterate over the rest of the overlaps */ > > - for (vma = vma->vm_next; vma; vma = vma->vm_next) { > > - unsigned long overlap_len; > > - > > - if (vma->vm_start > end) > > - break; > > + for_each_vma_range(vmi, vma, end) { > > + unsigned long vm_start = max(addr, vma->vm_start); > > + unsigned long vm_end = min(end, vma->vm_end); > > > > - overlap_len = min(end, vma->vm_end) - vma->vm_start; > > - nr_pages += overlap_len >> PAGE_SHIFT; > > + nr_pages += (vm_end - vm_start) / PAGE_SIZE; > > } > > > > return nr_pages; >
diff --git a/mm/mmap.c b/mm/mmap.c index 9fee6e6b276f..de78fc0ce809 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -669,29 +669,19 @@ munmap_vma_range(struct mm_struct *mm, unsigned long start, unsigned long len, return 0; } + static unsigned long count_vma_pages_range(struct mm_struct *mm, unsigned long addr, unsigned long end) { - unsigned long nr_pages = 0; + VMA_ITERATOR(vmi, mm, addr); struct vm_area_struct *vma; + unsigned long nr_pages = 0; - /* Find first overlapping mapping */ - vma = find_vma_intersection(mm, addr, end); - if (!vma) - return 0; - - nr_pages = (min(end, vma->vm_end) - - max(addr, vma->vm_start)) >> PAGE_SHIFT; - - /* Iterate over the rest of the overlaps */ - for (vma = vma->vm_next; vma; vma = vma->vm_next) { - unsigned long overlap_len; - - if (vma->vm_start > end) - break; + for_each_vma_range(vmi, vma, end) { + unsigned long vm_start = max(addr, vma->vm_start); + unsigned long vm_end = min(end, vma->vm_end); - overlap_len = min(end, vma->vm_end) - vma->vm_start; - nr_pages += overlap_len >> PAGE_SHIFT; + nr_pages += (vm_end - vm_start) / PAGE_SIZE; } return nr_pages;