| Message ID | 20221216192012.13562-1-mike.kravetz@oracle.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [RFC] mm: remove zap_page_range and change callers to use zap_vma_page_range | expand |
On Fri 16-12-22 11:20:12, Mike Kravetz wrote: > zap_page_range was originally designed to unmap pages within an address > range that could span multiple vmas. While working on [1], it was > discovered that all callers of zap_page_range pass a range entirely within > a single vma. In addition, the mmu notification call within zap_page > range does not correctly handle ranges that span multiple vmas as calls > should be vma specific. Could you spend a sentence or two explaining what is wrong here? > Instead of fixing zap_page_range, change all callers to use the new > routine zap_vma_page_range. zap_vma_page_range is just a wrapper around > zap_page_range_single passing in NULL zap details. The name is also > more in line with other exported routines that operate within a vma. > We can then remove zap_page_range. I would stick with zap_page_range_single rather than adding a new wrapper but nothing really critical. > Also, change madvise_dontneed_single_vma to use this new routine. > > [1] https://lore.kernel.org/linux-mm/20221114235507.294320-2-mike.kravetz@oracle.com/ > Suggested-by: Peter Xu <peterx@redhat.com> > Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Other than that LGTM Acked-by: Michal Hocko <mhocko@suse.com> Thanks! > --- > arch/arm64/kernel/vdso.c | 4 ++-- > arch/powerpc/kernel/vdso.c | 2 +- > arch/powerpc/platforms/book3s/vas-api.c | 2 +- > arch/powerpc/platforms/pseries/vas.c | 2 +- > arch/riscv/kernel/vdso.c | 4 ++-- > arch/s390/kernel/vdso.c | 2 +- > arch/s390/mm/gmap.c | 2 +- > arch/x86/entry/vdso/vma.c | 2 +- > drivers/android/binder_alloc.c | 2 +- > include/linux/mm.h | 7 ++++-- > mm/madvise.c | 4 ++-- > mm/memory.c | 30 ------------------------- > mm/page-writeback.c | 2 +- > net/ipv4/tcp.c | 6 ++--- > 14 files changed, 22 insertions(+), 49 deletions(-) > > diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c > index e59a32aa0c49..a7b10e182f78 100644 > --- a/arch/arm64/kernel/vdso.c > +++ b/arch/arm64/kernel/vdso.c > @@ -141,10 +141,10 @@ int vdso_join_timens(struct task_struct *task, struct time_namespace *ns) > unsigned long size = vma->vm_end - vma->vm_start; > > if (vma_is_special_mapping(vma, vdso_info[VDSO_ABI_AA64].dm)) > - zap_page_range(vma, vma->vm_start, size); > + zap_vma_page_range(vma, vma->vm_start, size); > #ifdef CONFIG_COMPAT_VDSO > if (vma_is_special_mapping(vma, vdso_info[VDSO_ABI_AA32].dm)) > - zap_page_range(vma, vma->vm_start, size); > + zap_vma_page_range(vma, vma->vm_start, size); > #endif > } > > diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c > index 507f8228f983..479d70fe8c55 100644 > --- a/arch/powerpc/kernel/vdso.c > +++ b/arch/powerpc/kernel/vdso.c > @@ -123,7 +123,7 @@ int vdso_join_timens(struct task_struct *task, struct time_namespace *ns) > unsigned long size = vma->vm_end - vma->vm_start; > > if (vma_is_special_mapping(vma, &vvar_spec)) > - zap_page_range(vma, vma->vm_start, size); > + zap_vma_page_range(vma, vma->vm_start, size); > } > mmap_read_unlock(mm); > > diff --git a/arch/powerpc/platforms/book3s/vas-api.c b/arch/powerpc/platforms/book3s/vas-api.c > index eb5bed333750..8f57388b760b 100644 > --- a/arch/powerpc/platforms/book3s/vas-api.c > +++ b/arch/powerpc/platforms/book3s/vas-api.c > @@ -414,7 +414,7 @@ static vm_fault_t vas_mmap_fault(struct vm_fault *vmf) > /* > * When the LPAR lost credits due to core removal or during > * migration, invalidate the existing mapping for the current > - * paste addresses and set windows in-active (zap_page_range in > + * paste addresses and set windows in-active (zap_vma_page_range in > * reconfig_close_windows()). > * New mapping will be done later after migration or new credits > * available. So continue to receive faults if the user space > diff --git a/arch/powerpc/platforms/pseries/vas.c b/arch/powerpc/platforms/pseries/vas.c > index 4ad6e510d405..2aef8d9295a2 100644 > --- a/arch/powerpc/platforms/pseries/vas.c > +++ b/arch/powerpc/platforms/pseries/vas.c > @@ -760,7 +760,7 @@ static int reconfig_close_windows(struct vas_caps *vcap, int excess_creds, > * is done before the original mmap() and after the ioctl. > */ > if (vma) > - zap_page_range(vma, vma->vm_start, > + zap_vma_page_range(vma, vma->vm_start, > vma->vm_end - vma->vm_start); > > mmap_write_unlock(task_ref->mm); > diff --git a/arch/riscv/kernel/vdso.c b/arch/riscv/kernel/vdso.c > index e410275918ac..a405119da2c0 100644 > --- a/arch/riscv/kernel/vdso.c > +++ b/arch/riscv/kernel/vdso.c > @@ -127,10 +127,10 @@ int vdso_join_timens(struct task_struct *task, struct time_namespace *ns) > unsigned long size = vma->vm_end - vma->vm_start; > > if (vma_is_special_mapping(vma, vdso_info.dm)) > - zap_page_range(vma, vma->vm_start, size); > + zap_vma_page_range(vma, vma->vm_start, size); > #ifdef CONFIG_COMPAT > if (vma_is_special_mapping(vma, compat_vdso_info.dm)) > - zap_page_range(vma, vma->vm_start, size); > + zap_vma_page_range(vma, vma->vm_start, size); > #endif > } > > diff --git a/arch/s390/kernel/vdso.c b/arch/s390/kernel/vdso.c > index ff7bf4432229..eccfcd505403 100644 > --- a/arch/s390/kernel/vdso.c > +++ b/arch/s390/kernel/vdso.c > @@ -63,7 +63,7 @@ int vdso_join_timens(struct task_struct *task, struct time_namespace *ns) > > if (!vma_is_special_mapping(vma, &vvar_mapping)) > continue; > - zap_page_range(vma, vma->vm_start, size); > + zap_vma_page_range(vma, vma->vm_start, size); > break; > } > mmap_read_unlock(mm); > diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c > index 74e1d873dce0..67d998152142 100644 > --- a/arch/s390/mm/gmap.c > +++ b/arch/s390/mm/gmap.c > @@ -722,7 +722,7 @@ void gmap_discard(struct gmap *gmap, unsigned long from, unsigned long to) > if (is_vm_hugetlb_page(vma)) > continue; > size = min(to - gaddr, PMD_SIZE - (gaddr & ~PMD_MASK)); > - zap_page_range(vma, vmaddr, size); > + zap_vma_page_range(vma, vmaddr, size); > } > mmap_read_unlock(gmap->mm); > } > diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c > index b8f3f9b9e53c..5aafbd19e869 100644 > --- a/arch/x86/entry/vdso/vma.c > +++ b/arch/x86/entry/vdso/vma.c > @@ -116,7 +116,7 @@ int vdso_join_timens(struct task_struct *task, struct time_namespace *ns) > unsigned long size = vma->vm_end - vma->vm_start; > > if (vma_is_special_mapping(vma, &vvar_mapping)) > - zap_page_range(vma, vma->vm_start, size); > + zap_vma_page_range(vma, vma->vm_start, size); > } > mmap_read_unlock(mm); > > diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c > index 4ad42b0f75cd..f7f10248c742 100644 > --- a/drivers/android/binder_alloc.c > +++ b/drivers/android/binder_alloc.c > @@ -1019,7 +1019,7 @@ enum lru_status binder_alloc_free_page(struct list_head *item, > if (vma) { > trace_binder_unmap_user_start(alloc, index); > > - zap_page_range(vma, page_addr, PAGE_SIZE); > + zap_vma_page_range(vma, page_addr, PAGE_SIZE); > > trace_binder_unmap_user_end(alloc, index); > } > diff --git a/include/linux/mm.h b/include/linux/mm.h > index 6b28eb9c6ea2..706efaf95783 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -1980,10 +1980,13 @@ struct page *vm_normal_page_pmd(struct vm_area_struct *vma, unsigned long addr, > > void zap_vma_ptes(struct vm_area_struct *vma, unsigned long address, > unsigned long size); > -void zap_page_range(struct vm_area_struct *vma, unsigned long address, > - unsigned long size); > void zap_page_range_single(struct vm_area_struct *vma, unsigned long address, > unsigned long size, struct zap_details *details); > +static inline void zap_vma_page_range(struct vm_area_struct *vma, > + unsigned long address, unsigned long size) > +{ > + zap_page_range_single(vma, address, size, NULL); > +} > void unmap_vmas(struct mmu_gather *tlb, struct maple_tree *mt, > struct vm_area_struct *start_vma, unsigned long start, > unsigned long end); > diff --git a/mm/madvise.c b/mm/madvise.c > index 87703a19bbef..3c4d9829d4e1 100644 > --- a/mm/madvise.c > +++ b/mm/madvise.c > @@ -787,7 +787,7 @@ static int madvise_free_single_vma(struct vm_area_struct *vma, > * Application no longer needs these pages. If the pages are dirty, > * it's OK to just throw them away. The app will be more careful about > * data it wants to keep. Be sure to free swap resources too. The > - * zap_page_range_single call sets things up for shrink_active_list to actually > + * zap_vma_page_range call sets things up for shrink_active_list to actually > * free these pages later if no one else has touched them in the meantime, > * although we could add these pages to a global reuse list for > * shrink_active_list to pick up before reclaiming other pages. > @@ -805,7 +805,7 @@ static int madvise_free_single_vma(struct vm_area_struct *vma, > static long madvise_dontneed_single_vma(struct vm_area_struct *vma, > unsigned long start, unsigned long end) > { > - zap_page_range_single(vma, start, end - start, NULL); > + zap_vma_page_range(vma, start, end - start); > return 0; > } > > diff --git a/mm/memory.c b/mm/memory.c > index 5b2c137dfb2a..e953a0108278 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -1687,36 +1687,6 @@ void unmap_vmas(struct mmu_gather *tlb, struct maple_tree *mt, > mmu_notifier_invalidate_range_end(&range); > } > > -/** > - * zap_page_range - remove user pages in a given range > - * @vma: vm_area_struct holding the applicable pages > - * @start: starting address of pages to zap > - * @size: number of bytes to zap > - * > - * Caller must protect the VMA list > - */ > -void zap_page_range(struct vm_area_struct *vma, unsigned long start, > - unsigned long size) > -{ > - struct maple_tree *mt = &vma->vm_mm->mm_mt; > - unsigned long end = start + size; > - struct mmu_notifier_range range; > - struct mmu_gather tlb; > - MA_STATE(mas, mt, vma->vm_end, vma->vm_end); > - > - lru_add_drain(); > - mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, vma->vm_mm, > - start, start + size); > - tlb_gather_mmu(&tlb, vma->vm_mm); > - update_hiwater_rss(vma->vm_mm); > - mmu_notifier_invalidate_range_start(&range); > - do { > - unmap_single_vma(&tlb, vma, start, range.end, NULL); > - } while ((vma = mas_find(&mas, end - 1)) != NULL); > - mmu_notifier_invalidate_range_end(&range); > - tlb_finish_mmu(&tlb); > -} > - > /** > * zap_page_range_single - remove user pages in a given range > * @vma: vm_area_struct holding the applicable pages > diff --git a/mm/page-writeback.c b/mm/page-writeback.c > index ad608ef2a243..bd9fe6ff6557 100644 > --- a/mm/page-writeback.c > +++ b/mm/page-writeback.c > @@ -2713,7 +2713,7 @@ void folio_account_cleaned(struct folio *folio, struct bdi_writeback *wb) > * > * The caller must hold lock_page_memcg(). Most callers have the folio > * locked. A few have the folio blocked from truncation through other > - * means (eg zap_page_range() has it mapped and is holding the page table > + * means (eg zap_vma_page_range() has it mapped and is holding the page table > * lock). This can also be called from mark_buffer_dirty(), which I > * cannot prove is always protected against truncate. > */ > diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c > index c567d5e8053e..afaad3cfed00 100644 > --- a/net/ipv4/tcp.c > +++ b/net/ipv4/tcp.c > @@ -2092,7 +2092,7 @@ static int tcp_zerocopy_vm_insert_batch_error(struct vm_area_struct *vma, > maybe_zap_len = total_bytes_to_map - /* All bytes to map */ > *length + /* Mapped or pending */ > (pages_remaining * PAGE_SIZE); /* Failed map. */ > - zap_page_range(vma, *address, maybe_zap_len); > + zap_vma_page_range(vma, *address, maybe_zap_len); > err = 0; > } > > @@ -2100,7 +2100,7 @@ static int tcp_zerocopy_vm_insert_batch_error(struct vm_area_struct *vma, > unsigned long leftover_pages = pages_remaining; > int bytes_mapped; > > - /* We called zap_page_range, try to reinsert. */ > + /* We called zap_vma_page_range, try to reinsert. */ > err = vm_insert_pages(vma, *address, > pending_pages, > &pages_remaining); > @@ -2234,7 +2234,7 @@ static int tcp_zerocopy_receive(struct sock *sk, > total_bytes_to_map = avail_len & ~(PAGE_SIZE - 1); > if (total_bytes_to_map) { > if (!(zc->flags & TCP_RECEIVE_ZEROCOPY_FLAG_TLB_CLEAN_HINT)) > - zap_page_range(vma, address, total_bytes_to_map); > + zap_vma_page_range(vma, address, total_bytes_to_map); > zc->length = total_bytes_to_map; > zc->recv_skip_hint = 0; > } else { > -- > 2.38.1
On 12/19/22 13:06, Michal Hocko wrote: > On Fri 16-12-22 11:20:12, Mike Kravetz wrote: > > zap_page_range was originally designed to unmap pages within an address > > range that could span multiple vmas. While working on [1], it was > > discovered that all callers of zap_page_range pass a range entirely within > > a single vma. In addition, the mmu notification call within zap_page > > range does not correctly handle ranges that span multiple vmas as calls > > should be vma specific. > > Could you spend a sentence or two explaining what is wrong here? Hmmmm? My assumption was that the range passed to mmu_notifier_range_init() was supposed to be within the specified vma. When looking into the notifier routines, I could not find any documentation about the usage of the vma within the mmu_notifier_range structure. It was introduced with commit bf198b2b34bf "mm/mmu_notifier: pass down vma and reasons why mmu notifier is happening". However, I do not see this being used today. Of course, I could be missing something, so adding Jérôme. > > > Instead of fixing zap_page_range, change all callers to use the new > > routine zap_vma_page_range. zap_vma_page_range is just a wrapper around > > zap_page_range_single passing in NULL zap details. The name is also > > more in line with other exported routines that operate within a vma. > > We can then remove zap_page_range. > > I would stick with zap_page_range_single rather than adding a new > wrapper but nothing really critical. I am fine with doing that as well. My only reason for the wrapper is that all callers outside mm/memory.c would pass in NULL zap details. > > > Also, change madvise_dontneed_single_vma to use this new routine. > > > > [1] https://lore.kernel.org/linux-mm/20221114235507.294320-2-mike.kravetz@oracle.com/ > > Suggested-by: Peter Xu <peterx@redhat.com> > > Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> > > Other than that LGTM > Acked-by: Michal Hocko <mhocko@suse.com> > > Thanks! Thanks for taking a look.
On Fri, Dec 16, 2022 at 11:20:12AM -0800, Mike Kravetz wrote: > zap_page_range was originally designed to unmap pages within an address > range that could span multiple vmas. While working on [1], it was > discovered that all callers of zap_page_range pass a range entirely within > a single vma. In addition, the mmu notification call within zap_page > range does not correctly handle ranges that span multiple vmas as calls > should be vma specific. > > Instead of fixing zap_page_range, change all callers to use the new > routine zap_vma_page_range. zap_vma_page_range is just a wrapper around > zap_page_range_single passing in NULL zap details. The name is also > more in line with other exported routines that operate within a vma. > We can then remove zap_page_range. > > Also, change madvise_dontneed_single_vma to use this new routine. > > [1] https://lore.kernel.org/linux-mm/20221114235507.294320-2-mike.kravetz@oracle.com/ > Suggested-by: Peter Xu <peterx@redhat.com> > Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Acked-by: Peter Xu <peterx@redhat.com> Thanks!
Mike Kravetz <mike.kravetz@oracle.com> writes: > zap_page_range was originally designed to unmap pages within an address > range that could span multiple vmas. While working on [1], it was > discovered that all callers of zap_page_range pass a range entirely within > a single vma. In addition, the mmu notification call within zap_page > range does not correctly handle ranges that span multiple vmas as calls > should be vma specific. > > Instead of fixing zap_page_range, change all callers to use the new > routine zap_vma_page_range. zap_vma_page_range is just a wrapper around > zap_page_range_single passing in NULL zap details. The name is also > more in line with other exported routines that operate within a vma. > We can then remove zap_page_range. > > Also, change madvise_dontneed_single_vma to use this new routine. > > [1] https://lore.kernel.org/linux-mm/20221114235507.294320-2-mike.kravetz@oracle.com/ > Suggested-by: Peter Xu <peterx@redhat.com> > Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> > --- > arch/arm64/kernel/vdso.c | 4 ++-- > arch/powerpc/kernel/vdso.c | 2 +- > arch/powerpc/platforms/book3s/vas-api.c | 2 +- > arch/powerpc/platforms/pseries/vas.c | 2 +- Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) cheers
> unsigned long size = vma->vm_end - vma->vm_start; > > if (vma_is_special_mapping(vma, vdso_info[VDSO_ABI_AA64].dm)) > - zap_page_range(vma, vma->vm_start, size); > + zap_vma_page_range(vma, vma->vm_start, size); > #ifdef CONFIG_COMPAT_VDSO > if (vma_is_special_mapping(vma, vdso_info[VDSO_ABI_AA32].dm)) > - zap_page_range(vma, vma->vm_start, size); > + zap_vma_page_range(vma, vma->vm_start, size); > #endif So for something called zap_vma_page_range I'd expect to just pass the vma and zap all of it, which this and many other callers want anyway. > +++ b/arch/s390/mm/gmap.c > @@ -722,7 +722,7 @@ void gmap_discard(struct gmap *gmap, unsigned long from, unsigned long to) > if (is_vm_hugetlb_page(vma)) > continue; > size = min(to - gaddr, PMD_SIZE - (gaddr & ~PMD_MASK)); > - zap_page_range(vma, vmaddr, size); > + zap_vma_page_range(vma, vmaddr, size); And then just call zap_page_range_single directly for those that don't want to zap the entire vma.
On 12/23/22 08:27, Christoph Hellwig wrote: > > unsigned long size = vma->vm_end - vma->vm_start; > > > > if (vma_is_special_mapping(vma, vdso_info[VDSO_ABI_AA64].dm)) > > - zap_page_range(vma, vma->vm_start, size); > > + zap_vma_page_range(vma, vma->vm_start, size); > > #ifdef CONFIG_COMPAT_VDSO > > if (vma_is_special_mapping(vma, vdso_info[VDSO_ABI_AA32].dm)) > > - zap_page_range(vma, vma->vm_start, size); > > + zap_vma_page_range(vma, vma->vm_start, size); > > #endif > > So for something called zap_vma_page_range I'd expect to just pass > the vma and zap all of it, which this and many other callers want > anyway. > > > +++ b/arch/s390/mm/gmap.c > > @@ -722,7 +722,7 @@ void gmap_discard(struct gmap *gmap, unsigned long from, unsigned long to) > > if (is_vm_hugetlb_page(vma)) > > continue; > > size = min(to - gaddr, PMD_SIZE - (gaddr & ~PMD_MASK)); > > - zap_page_range(vma, vmaddr, size); > > + zap_vma_page_range(vma, vmaddr, size); > > And then just call zap_page_range_single directly for those that > don't want to zap the entire vma. Thanks! This sounds like a good idea and I will incorporate in a new patch.
On Fri, 16 Dec 2022 11:20:12 PST (-0800), mike.kravetz@oracle.com wrote: > zap_page_range was originally designed to unmap pages within an address > range that could span multiple vmas. While working on [1], it was > discovered that all callers of zap_page_range pass a range entirely within > a single vma. In addition, the mmu notification call within zap_page > range does not correctly handle ranges that span multiple vmas as calls > should be vma specific. > > Instead of fixing zap_page_range, change all callers to use the new > routine zap_vma_page_range. zap_vma_page_range is just a wrapper around > zap_page_range_single passing in NULL zap details. The name is also > more in line with other exported routines that operate within a vma. > We can then remove zap_page_range. > > Also, change madvise_dontneed_single_vma to use this new routine. > > [1] https://lore.kernel.org/linux-mm/20221114235507.294320-2-mike.kravetz@oracle.com/ > Suggested-by: Peter Xu <peterx@redhat.com> > Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> > --- > arch/arm64/kernel/vdso.c | 4 ++-- > arch/powerpc/kernel/vdso.c | 2 +- > arch/powerpc/platforms/book3s/vas-api.c | 2 +- > arch/powerpc/platforms/pseries/vas.c | 2 +- > arch/riscv/kernel/vdso.c | 4 ++-- > arch/s390/kernel/vdso.c | 2 +- > arch/s390/mm/gmap.c | 2 +- > arch/x86/entry/vdso/vma.c | 2 +- > drivers/android/binder_alloc.c | 2 +- > include/linux/mm.h | 7 ++++-- > mm/madvise.c | 4 ++-- > mm/memory.c | 30 ------------------------- > mm/page-writeback.c | 2 +- > net/ipv4/tcp.c | 6 ++--- > 14 files changed, 22 insertions(+), 49 deletions(-) [snip] > diff --git a/arch/riscv/kernel/vdso.c b/arch/riscv/kernel/vdso.c > index e410275918ac..a405119da2c0 100644 > --- a/arch/riscv/kernel/vdso.c > +++ b/arch/riscv/kernel/vdso.c > @@ -127,10 +127,10 @@ int vdso_join_timens(struct task_struct *task, struct time_namespace *ns) > unsigned long size = vma->vm_end - vma->vm_start; > > if (vma_is_special_mapping(vma, vdso_info.dm)) > - zap_page_range(vma, vma->vm_start, size); > + zap_vma_page_range(vma, vma->vm_start, size); > #ifdef CONFIG_COMPAT > if (vma_is_special_mapping(vma, compat_vdso_info.dm)) > - zap_page_range(vma, vma->vm_start, size); > + zap_vma_page_range(vma, vma->vm_start, size); > #endif > } Acked-by: Palmer Dabbelt <palmer@rivosinc.com> # RISC-V Thanks!
Mike Kravetz <mike.kravetz@oracle.com> writes: > On 12/19/22 13:06, Michal Hocko wrote: >> On Fri 16-12-22 11:20:12, Mike Kravetz wrote: >> > zap_page_range was originally designed to unmap pages within an address >> > range that could span multiple vmas. While working on [1], it was >> > discovered that all callers of zap_page_range pass a range entirely within >> > a single vma. In addition, the mmu notification call within zap_page >> > range does not correctly handle ranges that span multiple vmas as calls >> > should be vma specific. >> >> Could you spend a sentence or two explaining what is wrong here? > > Hmmmm? My assumption was that the range passed to mmu_notifier_range_init() > was supposed to be within the specified vma. When looking into the notifier > routines, I could not find any documentation about the usage of the vma within > the mmu_notifier_range structure. It was introduced with commit bf198b2b34bf > "mm/mmu_notifier: pass down vma and reasons why mmu notifier is happening". > However, I do not see this being used today. > > Of course, I could be missing something, so adding Jérôme. The only use for mmu_notifier_range->vma I can find is in mmu_notifier_range_update_to_read_only() which was introduced in c6d23413f81b ("mm/mmu_notifier: mmu_notifier_range_update_to_read_only() helper"). However there are no users of that symbol so I think we can remove it along with the mmu_notifier_range->vma field. I will put togeather a patch to do that. >> >> > Instead of fixing zap_page_range, change all callers to use the new >> > routine zap_vma_page_range. zap_vma_page_range is just a wrapper around >> > zap_page_range_single passing in NULL zap details. The name is also >> > more in line with other exported routines that operate within a vma. >> > We can then remove zap_page_range. >> >> I would stick with zap_page_range_single rather than adding a new >> wrapper but nothing really critical. > > I am fine with doing that as well. My only reason for the wrapper is that all > callers outside mm/memory.c would pass in NULL zap details. > >> >> > Also, change madvise_dontneed_single_vma to use this new routine. >> > >> > [1] https://lore.kernel.org/linux-mm/20221114235507.294320-2-mike.kravetz@oracle.com/ >> > Suggested-by: Peter Xu <peterx@redhat.com> >> > Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> >> >> Other than that LGTM >> Acked-by: Michal Hocko <mhocko@suse.com> >> >> Thanks! > > Thanks for taking a look.
diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c index e59a32aa0c49..a7b10e182f78 100644 --- a/arch/arm64/kernel/vdso.c +++ b/arch/arm64/kernel/vdso.c @@ -141,10 +141,10 @@ int vdso_join_timens(struct task_struct *task, struct time_namespace *ns) unsigned long size = vma->vm_end - vma->vm_start; if (vma_is_special_mapping(vma, vdso_info[VDSO_ABI_AA64].dm)) - zap_page_range(vma, vma->vm_start, size); + zap_vma_page_range(vma, vma->vm_start, size); #ifdef CONFIG_COMPAT_VDSO if (vma_is_special_mapping(vma, vdso_info[VDSO_ABI_AA32].dm)) - zap_page_range(vma, vma->vm_start, size); + zap_vma_page_range(vma, vma->vm_start, size); #endif } diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c index 507f8228f983..479d70fe8c55 100644 --- a/arch/powerpc/kernel/vdso.c +++ b/arch/powerpc/kernel/vdso.c @@ -123,7 +123,7 @@ int vdso_join_timens(struct task_struct *task, struct time_namespace *ns) unsigned long size = vma->vm_end - vma->vm_start; if (vma_is_special_mapping(vma, &vvar_spec)) - zap_page_range(vma, vma->vm_start, size); + zap_vma_page_range(vma, vma->vm_start, size); } mmap_read_unlock(mm); diff --git a/arch/powerpc/platforms/book3s/vas-api.c b/arch/powerpc/platforms/book3s/vas-api.c index eb5bed333750..8f57388b760b 100644 --- a/arch/powerpc/platforms/book3s/vas-api.c +++ b/arch/powerpc/platforms/book3s/vas-api.c @@ -414,7 +414,7 @@ static vm_fault_t vas_mmap_fault(struct vm_fault *vmf) /* * When the LPAR lost credits due to core removal or during * migration, invalidate the existing mapping for the current - * paste addresses and set windows in-active (zap_page_range in + * paste addresses and set windows in-active (zap_vma_page_range in * reconfig_close_windows()). * New mapping will be done later after migration or new credits * available. So continue to receive faults if the user space diff --git a/arch/powerpc/platforms/pseries/vas.c b/arch/powerpc/platforms/pseries/vas.c index 4ad6e510d405..2aef8d9295a2 100644 --- a/arch/powerpc/platforms/pseries/vas.c +++ b/arch/powerpc/platforms/pseries/vas.c @@ -760,7 +760,7 @@ static int reconfig_close_windows(struct vas_caps *vcap, int excess_creds, * is done before the original mmap() and after the ioctl. */ if (vma) - zap_page_range(vma, vma->vm_start, + zap_vma_page_range(vma, vma->vm_start, vma->vm_end - vma->vm_start); mmap_write_unlock(task_ref->mm); diff --git a/arch/riscv/kernel/vdso.c b/arch/riscv/kernel/vdso.c index e410275918ac..a405119da2c0 100644 --- a/arch/riscv/kernel/vdso.c +++ b/arch/riscv/kernel/vdso.c @@ -127,10 +127,10 @@ int vdso_join_timens(struct task_struct *task, struct time_namespace *ns) unsigned long size = vma->vm_end - vma->vm_start; if (vma_is_special_mapping(vma, vdso_info.dm)) - zap_page_range(vma, vma->vm_start, size); + zap_vma_page_range(vma, vma->vm_start, size); #ifdef CONFIG_COMPAT if (vma_is_special_mapping(vma, compat_vdso_info.dm)) - zap_page_range(vma, vma->vm_start, size); + zap_vma_page_range(vma, vma->vm_start, size); #endif } diff --git a/arch/s390/kernel/vdso.c b/arch/s390/kernel/vdso.c index ff7bf4432229..eccfcd505403 100644 --- a/arch/s390/kernel/vdso.c +++ b/arch/s390/kernel/vdso.c @@ -63,7 +63,7 @@ int vdso_join_timens(struct task_struct *task, struct time_namespace *ns) if (!vma_is_special_mapping(vma, &vvar_mapping)) continue; - zap_page_range(vma, vma->vm_start, size); + zap_vma_page_range(vma, vma->vm_start, size); break; } mmap_read_unlock(mm); diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c index 74e1d873dce0..67d998152142 100644 --- a/arch/s390/mm/gmap.c +++ b/arch/s390/mm/gmap.c @@ -722,7 +722,7 @@ void gmap_discard(struct gmap *gmap, unsigned long from, unsigned long to) if (is_vm_hugetlb_page(vma)) continue; size = min(to - gaddr, PMD_SIZE - (gaddr & ~PMD_MASK)); - zap_page_range(vma, vmaddr, size); + zap_vma_page_range(vma, vmaddr, size); } mmap_read_unlock(gmap->mm); } diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c index b8f3f9b9e53c..5aafbd19e869 100644 --- a/arch/x86/entry/vdso/vma.c +++ b/arch/x86/entry/vdso/vma.c @@ -116,7 +116,7 @@ int vdso_join_timens(struct task_struct *task, struct time_namespace *ns) unsigned long size = vma->vm_end - vma->vm_start; if (vma_is_special_mapping(vma, &vvar_mapping)) - zap_page_range(vma, vma->vm_start, size); + zap_vma_page_range(vma, vma->vm_start, size); } mmap_read_unlock(mm); diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c index 4ad42b0f75cd..f7f10248c742 100644 --- a/drivers/android/binder_alloc.c +++ b/drivers/android/binder_alloc.c @@ -1019,7 +1019,7 @@ enum lru_status binder_alloc_free_page(struct list_head *item, if (vma) { trace_binder_unmap_user_start(alloc, index); - zap_page_range(vma, page_addr, PAGE_SIZE); + zap_vma_page_range(vma, page_addr, PAGE_SIZE); trace_binder_unmap_user_end(alloc, index); } diff --git a/include/linux/mm.h b/include/linux/mm.h index 6b28eb9c6ea2..706efaf95783 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1980,10 +1980,13 @@ struct page *vm_normal_page_pmd(struct vm_area_struct *vma, unsigned long addr, void zap_vma_ptes(struct vm_area_struct *vma, unsigned long address, unsigned long size); -void zap_page_range(struct vm_area_struct *vma, unsigned long address, - unsigned long size); void zap_page_range_single(struct vm_area_struct *vma, unsigned long address, unsigned long size, struct zap_details *details); +static inline void zap_vma_page_range(struct vm_area_struct *vma, + unsigned long address, unsigned long size) +{ + zap_page_range_single(vma, address, size, NULL); +} void unmap_vmas(struct mmu_gather *tlb, struct maple_tree *mt, struct vm_area_struct *start_vma, unsigned long start, unsigned long end); diff --git a/mm/madvise.c b/mm/madvise.c index 87703a19bbef..3c4d9829d4e1 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -787,7 +787,7 @@ static int madvise_free_single_vma(struct vm_area_struct *vma, * Application no longer needs these pages. If the pages are dirty, * it's OK to just throw them away. The app will be more careful about * data it wants to keep. Be sure to free swap resources too. The - * zap_page_range_single call sets things up for shrink_active_list to actually + * zap_vma_page_range call sets things up for shrink_active_list to actually * free these pages later if no one else has touched them in the meantime, * although we could add these pages to a global reuse list for * shrink_active_list to pick up before reclaiming other pages. @@ -805,7 +805,7 @@ static int madvise_free_single_vma(struct vm_area_struct *vma, static long madvise_dontneed_single_vma(struct vm_area_struct *vma, unsigned long start, unsigned long end) { - zap_page_range_single(vma, start, end - start, NULL); + zap_vma_page_range(vma, start, end - start); return 0; } diff --git a/mm/memory.c b/mm/memory.c index 5b2c137dfb2a..e953a0108278 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1687,36 +1687,6 @@ void unmap_vmas(struct mmu_gather *tlb, struct maple_tree *mt, mmu_notifier_invalidate_range_end(&range); } -/** - * zap_page_range - remove user pages in a given range - * @vma: vm_area_struct holding the applicable pages - * @start: starting address of pages to zap - * @size: number of bytes to zap - * - * Caller must protect the VMA list - */ -void zap_page_range(struct vm_area_struct *vma, unsigned long start, - unsigned long size) -{ - struct maple_tree *mt = &vma->vm_mm->mm_mt; - unsigned long end = start + size; - struct mmu_notifier_range range; - struct mmu_gather tlb; - MA_STATE(mas, mt, vma->vm_end, vma->vm_end); - - lru_add_drain(); - mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, vma->vm_mm, - start, start + size); - tlb_gather_mmu(&tlb, vma->vm_mm); - update_hiwater_rss(vma->vm_mm); - mmu_notifier_invalidate_range_start(&range); - do { - unmap_single_vma(&tlb, vma, start, range.end, NULL); - } while ((vma = mas_find(&mas, end - 1)) != NULL); - mmu_notifier_invalidate_range_end(&range); - tlb_finish_mmu(&tlb); -} - /** * zap_page_range_single - remove user pages in a given range * @vma: vm_area_struct holding the applicable pages diff --git a/mm/page-writeback.c b/mm/page-writeback.c index ad608ef2a243..bd9fe6ff6557 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -2713,7 +2713,7 @@ void folio_account_cleaned(struct folio *folio, struct bdi_writeback *wb) * * The caller must hold lock_page_memcg(). Most callers have the folio * locked. A few have the folio blocked from truncation through other - * means (eg zap_page_range() has it mapped and is holding the page table + * means (eg zap_vma_page_range() has it mapped and is holding the page table * lock). This can also be called from mark_buffer_dirty(), which I * cannot prove is always protected against truncate. */ diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index c567d5e8053e..afaad3cfed00 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2092,7 +2092,7 @@ static int tcp_zerocopy_vm_insert_batch_error(struct vm_area_struct *vma, maybe_zap_len = total_bytes_to_map - /* All bytes to map */ *length + /* Mapped or pending */ (pages_remaining * PAGE_SIZE); /* Failed map. */ - zap_page_range(vma, *address, maybe_zap_len); + zap_vma_page_range(vma, *address, maybe_zap_len); err = 0; } @@ -2100,7 +2100,7 @@ static int tcp_zerocopy_vm_insert_batch_error(struct vm_area_struct *vma, unsigned long leftover_pages = pages_remaining; int bytes_mapped; - /* We called zap_page_range, try to reinsert. */ + /* We called zap_vma_page_range, try to reinsert. */ err = vm_insert_pages(vma, *address, pending_pages, &pages_remaining); @@ -2234,7 +2234,7 @@ static int tcp_zerocopy_receive(struct sock *sk, total_bytes_to_map = avail_len & ~(PAGE_SIZE - 1); if (total_bytes_to_map) { if (!(zc->flags & TCP_RECEIVE_ZEROCOPY_FLAG_TLB_CLEAN_HINT)) - zap_page_range(vma, address, total_bytes_to_map); + zap_vma_page_range(vma, address, total_bytes_to_map); zc->length = total_bytes_to_map; zc->recv_skip_hint = 0; } else {
zap_page_range was originally designed to unmap pages within an address range that could span multiple vmas. While working on [1], it was discovered that all callers of zap_page_range pass a range entirely within a single vma. In addition, the mmu notification call within zap_page range does not correctly handle ranges that span multiple vmas as calls should be vma specific. Instead of fixing zap_page_range, change all callers to use the new routine zap_vma_page_range. zap_vma_page_range is just a wrapper around zap_page_range_single passing in NULL zap details. The name is also more in line with other exported routines that operate within a vma. We can then remove zap_page_range. Also, change madvise_dontneed_single_vma to use this new routine. [1] https://lore.kernel.org/linux-mm/20221114235507.294320-2-mike.kravetz@oracle.com/ Suggested-by: Peter Xu <peterx@redhat.com> Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> --- arch/arm64/kernel/vdso.c | 4 ++-- arch/powerpc/kernel/vdso.c | 2 +- arch/powerpc/platforms/book3s/vas-api.c | 2 +- arch/powerpc/platforms/pseries/vas.c | 2 +- arch/riscv/kernel/vdso.c | 4 ++-- arch/s390/kernel/vdso.c | 2 +- arch/s390/mm/gmap.c | 2 +- arch/x86/entry/vdso/vma.c | 2 +- drivers/android/binder_alloc.c | 2 +- include/linux/mm.h | 7 ++++-- mm/madvise.c | 4 ++-- mm/memory.c | 30 ------------------------- mm/page-writeback.c | 2 +- net/ipv4/tcp.c | 6 ++--- 14 files changed, 22 insertions(+), 49 deletions(-)