Re: linux-next: manual merge of the bpf-next tree with the mm-stable tree

[Alexei Starovoitov <alexei.starovoitov@gmail.com>]

On Thu, Mar 14, 2024 at 2:34 AM Uladzislau Rezki <urezki@gmail.com> wrote:
>
> > Hi all,
> >
> > On Wed, 13 Mar 2024 10:51:17 +1100 Stephen Rothwell <sfr@canb.auug.org.au> wrote:
> > >
> > > On Thu, 7 Mar 2024 12:36:19 +1100 Stephen Rothwell <sfr@canb.auug.org.au> wrote:
> > > >
> > > > Today's linux-next merge of the bpf-next tree got a conflict in:
> > > >
> > > >   mm/vmalloc.c
> > > >
> > > > between commit:
> > > >
> > > >   8e1d743f2c26 ("mm: vmalloc: support multiple nodes in vmallocinfo")
> > > >
> > > > from the mm-stable tree and commit:
> > > >
> > > >   e6f798225a31 ("mm: Introduce VM_SPARSE kind and vm_area_[un]map_pages().")
> > > >
> > > > from the bpf-next tree.
> > > >
> > > > I fixed it up (I think - see below) and can carry the fix as necessary.
> > > > This is now fixed as far as linux-next is concerned, but any non trivial
> > > > conflicts should be mentioned to your upstream maintainer when your tree
> > > > is submitted for merging.  You may also want to consider cooperating
> > > > with the maintainer of the conflicting tree to minimise any particularly
> > > > complex conflicts.
> > > >
> > > >
> > > > diff --cc mm/vmalloc.c
> > > > index 25a8df497255,e5b8c70950bc..000000000000
> > > > --- a/mm/vmalloc.c
> > > > +++ b/mm/vmalloc.c
> > > > @@@ -4755,81 -4423,70 +4820,84 @@@ static void show_numa_info(struct seq_f
> > > >
> > > >   static void show_purge_info(struct seq_file *m)
> > > >   {
> > > >  +        struct vmap_node *vn;
> > > >           struct vmap_area *va;
> > > >  +        int i;
> > > >
> > > >  -        spin_lock(&purge_vmap_area_lock);
> > > >  -        list_for_each_entry(va, &purge_vmap_area_list, list) {
> > > >  -                seq_printf(m, "0x%pK-0x%pK %7ld unpurged vm_area\n",
> > > >  -                        (void *)va->va_start, (void *)va->va_end,
> > > >  -                        va->va_end - va->va_start);
> > > >  -        }
> > > >  -        spin_unlock(&purge_vmap_area_lock);
> > > >  -}
> > > >  +        for (i = 0; i < nr_vmap_nodes; i++) {
> > > >  +                vn = &vmap_nodes[i];
> > > >
> > > >  -static int s_show(struct seq_file *m, void *p)
> > > >  -{
> > > >  -        struct vmap_area *va;
> > > >  -        struct vm_struct *v;
> > > >  -
> > > >  -        va = list_entry(p, struct vmap_area, list);
> > > >  -
> > > >  -        if (!va->vm) {
> > > >  -                if (va->flags & VMAP_RAM)
> > > >  -                        seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n",
> > > >  +                spin_lock(&vn->lazy.lock);
> > > >  +                list_for_each_entry(va, &vn->lazy.head, list) {
> > > >  +                        seq_printf(m, "0x%pK-0x%pK %7ld unpurged vm_area\n",
> > > >                                   (void *)va->va_start, (void *)va->va_end,
> > > >                                   va->va_end - va->va_start);
> > > >  -
> > > >  -                goto final;
> > > >  +                }
> > > >  +                spin_unlock(&vn->lazy.lock);
> > > >           }
> > > >  +}
> > > >
> > > >  -        v = va->vm;
> > > >  +static int vmalloc_info_show(struct seq_file *m, void *p)
> > > >  +{
> > > >  +        struct vmap_node *vn;
> > > >  +        struct vmap_area *va;
> > > >  +        struct vm_struct *v;
> > > >  +        int i;
> > > >
> > > >  -        seq_printf(m, "0x%pK-0x%pK %7ld",
> > > >  -                v->addr, v->addr + v->size, v->size);
> > > >  +        for (i = 0; i < nr_vmap_nodes; i++) {
> > > >  +                vn = &vmap_nodes[i];
> > > >
> > > >  -        if (v->caller)
> > > >  -                seq_printf(m, " %pS", v->caller);
> > > >  +                spin_lock(&vn->busy.lock);
> > > >  +                list_for_each_entry(va, &vn->busy.head, list) {
> > > >  +                        if (!va->vm) {
> > > >  +                                if (va->flags & VMAP_RAM)
> > > >  +                                        seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n",
> > > >  +                                                (void *)va->va_start, (void *)va->va_end,
> > > >  +                                                va->va_end - va->va_start);
> > > >
> > > >  -        if (v->nr_pages)
> > > >  -                seq_printf(m, " pages=%d", v->nr_pages);
> > > >  +                                continue;
> > > >  +                        }
> > > >
> > > >  -        if (v->phys_addr)
> > > >  -                seq_printf(m, " phys=%pa", &v->phys_addr);
> > > >  +                        v = va->vm;
> > > >
> > > >  -        if (v->flags & VM_IOREMAP)
> > > >  -                seq_puts(m, " ioremap");
> > > >  +                        seq_printf(m, "0x%pK-0x%pK %7ld",
> > > >  +                                v->addr, v->addr + v->size, v->size);
> > > >
> > > >  -        if (v->flags & VM_SPARSE)
> > > >  -                seq_puts(m, " sparse");
> > > >  +                        if (v->caller)
> > > >  +                                seq_printf(m, " %pS", v->caller);
> > > >
> > > >  -        if (v->flags & VM_ALLOC)
> > > >  -                seq_puts(m, " vmalloc");
> > > >  +                        if (v->nr_pages)
> > > >  +                                seq_printf(m, " pages=%d", v->nr_pages);
> > > >
> > > >  -        if (v->flags & VM_MAP)
> > > >  -                seq_puts(m, " vmap");
> > > >  +                        if (v->phys_addr)
> > > >  +                                seq_printf(m, " phys=%pa", &v->phys_addr);
> > > >
> > > >  -        if (v->flags & VM_USERMAP)
> > > >  -                seq_puts(m, " user");
> > > >  +                        if (v->flags & VM_IOREMAP)
> > > >  +                                seq_puts(m, " ioremap");
> > > >
> > > >  -        if (v->flags & VM_DMA_COHERENT)
> > > >  -                seq_puts(m, " dma-coherent");
> > > > ++                        if (v->flags & VM_SPARSE)
> > > > ++                                seq_puts(m, " sparse");
> > > > +
> > > >  -        if (is_vmalloc_addr(v->pages))
> > > >  -                seq_puts(m, " vpages");
> > > >  +                        if (v->flags & VM_ALLOC)
> > > >  +                                seq_puts(m, " vmalloc");
> > > >
> > > >  -        show_numa_info(m, v);
> > > >  -        seq_putc(m, '\n');
> > > >  +                        if (v->flags & VM_MAP)
> > > >  +                                seq_puts(m, " vmap");
> > > >  +
> > > >  +                        if (v->flags & VM_USERMAP)
> > > >  +                                seq_puts(m, " user");
> > > >  +
> > > >  +                        if (v->flags & VM_DMA_COHERENT)
> > > >  +                                seq_puts(m, " dma-coherent");
> > > >  +
> > > >  +                        if (is_vmalloc_addr(v->pages))
> > > >  +                                seq_puts(m, " vpages");
> > > >  +
> > > >  +                        show_numa_info(m, v);
> > > >  +                        seq_putc(m, '\n');
> > > >  +                }
> > > >  +                spin_unlock(&vn->busy.lock);
> > > >  +        }
> > > >
> > > >           /*
> > > >            * As a final step, dump "unpurged" areas.
> > >
> > > This is now a conflict between the net-next tree and the mm-stable tree.
> >
> >  ... and now a conflict between te mm-stable tree and Linus' tree.
> >
> If you need some help with resolving conflicts i can help. The problem
> to me looks like:
>
> <snip>
> commit d7bca9199a27b8690ae1c71dc11f825154af7234
> Author: Alexei Starovoitov <ast@kernel.org>
> Date:   Fri Mar 8 09:12:54 2024 -0800
>
>     mm: Introduce vmap_page_range() to map pages in PCI address space
>
> commit e6f798225a31485e47a6e4f6aa07ee9fdf80c2cb
> Author: Alexei Starovoitov <ast@kernel.org>
> Date:   Mon Mar 4 19:05:16 2024 -0800
>
>     mm: Introduce VM_SPARSE kind and vm_area_[un]map_pages().
>
> commit 3e49a866c9dcbd8173e4f3e491293619a9e81fa4
> Author: Alexei Starovoitov <ast@kernel.org>
> Date:   Mon Mar 4 19:05:15 2024 -0800
>
>     mm: Enforce VM_IOREMAP flag and range in ioremap_page_range.
> <snip>
>
> those three patches were not based on linux-next and are currently
> in the Linus tree(bypassing mm-tree?). Whereas below work:
>
> mm: vmalloc: refactor vmalloc_dump_obj() function
> mm: vmalloc: improve description of vmap node layer
> mm: vmalloc: add a shrinker to drain vmap pools
> mm: vmalloc: set nr_nodes based on CPUs in a system
> mm: vmalloc: support multiple nodes in vmallocinfo
> mm: vmalloc: support multiple nodes in vread_iter
> mm: vmalloc: add a scan area of VA only once
> mm: vmalloc: offload free_vmap_area_lock lock
> mm: vmalloc: remove global purge_vmap_area_root rb-tree
> mm/vmalloc: remove vmap_area_list
> mm: vmalloc: remove global vmap_area_root rb-tree
> mm: vmalloc: move vmap_init_free_space() down in vmalloc.c
> mm: vmalloc: rename adjust_va_to_fit_type() function
> mm: vmalloc: add va_alloc() helper
>
> now should be based on Alexei Starovoitov base in order to resolve
> a small conflict.

Pls don't rebase anything.

> But you better know how to proceed. Just in case, if you need some
> support please let me know i can help with conflict resolving.

As Stephen said these two conflict:

> > >   8e1d743f2c26 ("mm: vmalloc: support multiple nodes in vmallocinfo")
> > >
> > >   e6f798225a31 ("mm: Introduce VM_SPARSE kind and vm_area_[un]map_pages().")

and conflict is trivial. It just looks big due to the indent change.