| Message ID | 20171215140947.26075-15-hch@lst.de (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 7003e3b1f64d |
| Headers | show |
On Fri, Dec 15, 2017 at 6:09 AM, Christoph Hellwig <hch@lst.de> wrote: > __radix_tree_insert already checks for duplicates and returns -EEXIST in > that case, so remove the duplicate (and racy) duplicates check. > > Signed-off-by: Christoph Hellwig <hch@lst.de> > Reviewed-by: Logan Gunthorpe <logang@deltatee.com> > --- > kernel/memremap.c | 11 ----------- > 1 file changed, 11 deletions(-) > > diff --git a/kernel/memremap.c b/kernel/memremap.c > index 891491ddccdb..901404094df1 100644 > --- a/kernel/memremap.c > +++ b/kernel/memremap.c > @@ -395,17 +395,6 @@ void *devm_memremap_pages(struct device *dev, struct resource *res, > align_end = align_start + align_size - 1; > > foreach_order_pgoff(res, order, pgoff) { > - struct dev_pagemap *dup; > - > - rcu_read_lock(); > - dup = find_dev_pagemap(res->start + PFN_PHYS(pgoff)); > - rcu_read_unlock(); > - if (dup) { > - dev_err(dev, "%s: %pr collides with mapping for %s\n", > - __func__, res, dev_name(dup->dev)); > - error = -EBUSY; > - break; > - } > error = __radix_tree_insert(&pgmap_radix, > PHYS_PFN(res->start) + pgoff, order, page_map); > if (error) { This is not racy, we'll catch the error on insert, and I think the extra debug information is useful for debugging a broken memory map or alignment math.
On Sun, Dec 17, 2017 at 09:34:11AM -0800, Dan Williams wrote: > This is not racy, we'll catch the error on insert, and I think the > extra debug information is useful for debugging a broken memory map or > alignment math. We can check for -Š•EXIST and print the warning, but it's a weird pattern for sure.
diff --git a/kernel/memremap.c b/kernel/memremap.c index 891491ddccdb..901404094df1 100644 --- a/kernel/memremap.c +++ b/kernel/memremap.c @@ -395,17 +395,6 @@ void *devm_memremap_pages(struct device *dev, struct resource *res, align_end = align_start + align_size - 1; foreach_order_pgoff(res, order, pgoff) { - struct dev_pagemap *dup; - - rcu_read_lock(); - dup = find_dev_pagemap(res->start + PFN_PHYS(pgoff)); - rcu_read_unlock(); - if (dup) { - dev_err(dev, "%s: %pr collides with mapping for %s\n", - __func__, res, dev_name(dup->dev)); - error = -EBUSY; - break; - } error = __radix_tree_insert(&pgmap_radix, PHYS_PFN(res->start) + pgoff, order, page_map); if (error) {