| Message ID | 20230113031921.64716-2-bhe@redhat.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mm/vmalloc.c: allow vread() to read out vm_map_ram areas | expand |
On Fri, Jan 13, 2023 at 11:19:15AM +0800, Baoquan He wrote: > In one vmap_block area, there could be three types of regions: region > being used which is allocated through vb_alloc(), dirty region which > is freed via vb_free() and free region. Among them, only used region > has available data. While there's no way to track those used regions > currently. > > Here, add bitmap field used_map into vmap_block, and set/clear it during > allocation or freeing regions of vmap_block area. > > This is a preparatoin for later use. > > Signed-off-by: Baoquan He <bhe@redhat.com> > --- > mm/vmalloc.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > index 428e0bee5c9c..d6ff058ef4d0 100644 > --- a/mm/vmalloc.c > +++ b/mm/vmalloc.c > @@ -1922,6 +1922,7 @@ struct vmap_block { > spinlock_t lock; > struct vmap_area *va; > unsigned long free, dirty; > + DECLARE_BITMAP(used_map, VMAP_BBMAP_BITS); > unsigned long dirty_min, dirty_max; /*< dirty range */ > struct list_head free_list; > struct rcu_head rcu_head; > @@ -1998,10 +1999,12 @@ static void *new_vmap_block(unsigned int order, gfp_t gfp_mask) > vb->va = va; > /* At least something should be left free */ > BUG_ON(VMAP_BBMAP_BITS <= (1UL << order)); > + bitmap_zero(vb->used_map, VMAP_BBMAP_BITS); > vb->free = VMAP_BBMAP_BITS - (1UL << order); > vb->dirty = 0; > vb->dirty_min = VMAP_BBMAP_BITS; > vb->dirty_max = 0; > + bitmap_set(vb->used_map, 0, (1UL << order)); > INIT_LIST_HEAD(&vb->free_list); > > vb_idx = addr_to_vb_idx(va->va_start); > @@ -2111,6 +2114,7 @@ static void *vb_alloc(unsigned long size, gfp_t gfp_mask) > pages_off = VMAP_BBMAP_BITS - vb->free; > vaddr = vmap_block_vaddr(vb->va->va_start, pages_off); > vb->free -= 1UL << order; > + bitmap_set(vb->used_map, pages_off, (1UL << order)); > if (vb->free == 0) { > spin_lock(&vbq->lock); > list_del_rcu(&vb->free_list); > @@ -2144,6 +2148,9 @@ static void vb_free(unsigned long addr, unsigned long size) > order = get_order(size); > offset = (addr & (VMAP_BLOCK_SIZE - 1)) >> PAGE_SHIFT; > vb = xa_load(&vmap_blocks, addr_to_vb_idx(addr)); > + spin_lock(&vb->lock); > + bitmap_clear(vb->used_map, offset, (1UL << order)); > + spin_unlock(&vb->lock); > > vunmap_range_noflush(addr, addr + size); > > -- > 2.34.1 > Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com> -- Uladzislau Rezki
On Fri, Jan 13, 2023 at 11:19:15AM +0800, Baoquan He wrote: > In one vmap_block area, there could be three types of regions: region > being used which is allocated through vb_alloc(), dirty region which > is freed via vb_free() and free region. Among them, only used region > has available data. While there's no way to track those used regions > currently. > > Here, add bitmap field used_map into vmap_block, and set/clear it during > allocation or freeing regions of vmap_block area. > > This is a preparatoin for later use. > > Signed-off-by: Baoquan He <bhe@redhat.com> > --- > mm/vmalloc.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > index 428e0bee5c9c..d6ff058ef4d0 100644 > --- a/mm/vmalloc.c > +++ b/mm/vmalloc.c > @@ -1922,6 +1922,7 @@ struct vmap_block { > spinlock_t lock; > struct vmap_area *va; > unsigned long free, dirty; > + DECLARE_BITMAP(used_map, VMAP_BBMAP_BITS); > unsigned long dirty_min, dirty_max; /*< dirty range */ > struct list_head free_list; > struct rcu_head rcu_head; > @@ -1998,10 +1999,12 @@ static void *new_vmap_block(unsigned int order, gfp_t gfp_mask) > vb->va = va; > /* At least something should be left free */ > BUG_ON(VMAP_BBMAP_BITS <= (1UL << order)); > + bitmap_zero(vb->used_map, VMAP_BBMAP_BITS); > vb->free = VMAP_BBMAP_BITS - (1UL << order); > vb->dirty = 0; > vb->dirty_min = VMAP_BBMAP_BITS; > vb->dirty_max = 0; > + bitmap_set(vb->used_map, 0, (1UL << order)); > INIT_LIST_HEAD(&vb->free_list); > > vb_idx = addr_to_vb_idx(va->va_start); > @@ -2111,6 +2114,7 @@ static void *vb_alloc(unsigned long size, gfp_t gfp_mask) > pages_off = VMAP_BBMAP_BITS - vb->free; > vaddr = vmap_block_vaddr(vb->va->va_start, pages_off); > vb->free -= 1UL << order; > + bitmap_set(vb->used_map, pages_off, (1UL << order)); > if (vb->free == 0) { > spin_lock(&vbq->lock); > list_del_rcu(&vb->free_list); > @@ -2144,6 +2148,9 @@ static void vb_free(unsigned long addr, unsigned long size) > order = get_order(size); > offset = (addr & (VMAP_BLOCK_SIZE - 1)) >> PAGE_SHIFT; > vb = xa_load(&vmap_blocks, addr_to_vb_idx(addr)); > + spin_lock(&vb->lock); > + bitmap_clear(vb->used_map, offset, (1UL << order)); > + spin_unlock(&vb->lock); > > vunmap_range_noflush(addr, addr + size); > > -- > 2.34.1 > Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com>
diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 428e0bee5c9c..d6ff058ef4d0 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -1922,6 +1922,7 @@ struct vmap_block { spinlock_t lock; struct vmap_area *va; unsigned long free, dirty; + DECLARE_BITMAP(used_map, VMAP_BBMAP_BITS); unsigned long dirty_min, dirty_max; /*< dirty range */ struct list_head free_list; struct rcu_head rcu_head; @@ -1998,10 +1999,12 @@ static void *new_vmap_block(unsigned int order, gfp_t gfp_mask) vb->va = va; /* At least something should be left free */ BUG_ON(VMAP_BBMAP_BITS <= (1UL << order)); + bitmap_zero(vb->used_map, VMAP_BBMAP_BITS); vb->free = VMAP_BBMAP_BITS - (1UL << order); vb->dirty = 0; vb->dirty_min = VMAP_BBMAP_BITS; vb->dirty_max = 0; + bitmap_set(vb->used_map, 0, (1UL << order)); INIT_LIST_HEAD(&vb->free_list); vb_idx = addr_to_vb_idx(va->va_start); @@ -2111,6 +2114,7 @@ static void *vb_alloc(unsigned long size, gfp_t gfp_mask) pages_off = VMAP_BBMAP_BITS - vb->free; vaddr = vmap_block_vaddr(vb->va->va_start, pages_off); vb->free -= 1UL << order; + bitmap_set(vb->used_map, pages_off, (1UL << order)); if (vb->free == 0) { spin_lock(&vbq->lock); list_del_rcu(&vb->free_list); @@ -2144,6 +2148,9 @@ static void vb_free(unsigned long addr, unsigned long size) order = get_order(size); offset = (addr & (VMAP_BLOCK_SIZE - 1)) >> PAGE_SHIFT; vb = xa_load(&vmap_blocks, addr_to_vb_idx(addr)); + spin_lock(&vb->lock); + bitmap_clear(vb->used_map, offset, (1UL << order)); + spin_unlock(&vb->lock); vunmap_range_noflush(addr, addr + size);
In one vmap_block area, there could be three types of regions: region being used which is allocated through vb_alloc(), dirty region which is freed via vb_free() and free region. Among them, only used region has available data. While there's no way to track those used regions currently. Here, add bitmap field used_map into vmap_block, and set/clear it during allocation or freeing regions of vmap_block area. This is a preparatoin for later use. Signed-off-by: Baoquan He <bhe@redhat.com> --- mm/vmalloc.c | 7 +++++++ 1 file changed, 7 insertions(+)