| Message ID | 20221221174454.1085130-2-urezki@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v2,1/3] mm: vmalloc: Avoid of calling __find_vmap_area() twise in __vunmap() | expand |
Looks good: Reviewed-by: Christoph Hellwig <hch@lst.de> On Wed, Dec 21, 2022 at 06:44:53PM +0100, Uladzislau Rezki (Sony) wrote: > Switch from find_vmap_area() to find_unlink_vmap_area() to prevent > a double access to the vmap_area_lock: one for finding area, second > time is for unlinking from a tree. > > Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> > --- > mm/vmalloc.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > index 28030d2441f1..17e688cc7357 100644 > --- a/mm/vmalloc.c > +++ b/mm/vmalloc.c > @@ -2251,7 +2251,7 @@ void vm_unmap_ram(const void *mem, unsigned int count) > return; > } > > - va = find_vmap_area(addr); > + va = find_unlink_vmap_area(addr); I can't find find_unlink_vmap_area in current -next, but shouldn't this also switch from free_vmap_area_noflush to something that doesn't unlink from the list and avoid the lock? In general the code could probably use a bit of refactoring to split unmapping from freeing.
diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 28030d2441f1..17e688cc7357 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -2251,7 +2251,7 @@ void vm_unmap_ram(const void *mem, unsigned int count) return; } - va = find_vmap_area(addr); + va = find_unlink_vmap_area(addr); BUG_ON(!va); debug_check_no_locks_freed((void *)va->va_start, (va->va_end - va->va_start));
Switch from find_vmap_area() to find_unlink_vmap_area() to prevent a double access to the vmap_area_lock: one for finding area, second time is for unlinking from a tree. Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> --- mm/vmalloc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)