Hi all,

On Wed, 13 Mar 2024 10:51:17 +1100 Stephen Rothwell [off-list ref] wrote:

quoted

On Thu, 7 Mar 2024 12:36:19 +1100 Stephen Rothwell [off-list ref] wrote:

quoted

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 [off-list ref]
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 [off-list ref]
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 [off-list ref]
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.

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.

--
Uladzislau Rezki