Re: [PATCH] mm: use proper type for cma_[alloc|release]

From: David Hildenbrand
Date: Wed Mar 31 2021 - 13:35:56 EST


On 31.03.21 18:40, Minchan Kim wrote:
size_t in cma_alloc is confusing since it makes people think
it's byte count, not pages. Change it to unsigned long[1].

The unsigned int in cma_release is also not right so change it.
Since we have unsigned long in cma_release, free_contig_range
should also respect it.

[1] 67a2e213e7e9, mm: cma: fix incorrect type conversion for size during dma allocation
Link: https://lore.kernel.org/linux-mm/20210324043434.GP1719932@xxxxxxxxxxxxxxxxxxxx/
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Signed-off-by: Minchan Kim <minchan@xxxxxxxxxx>
---
include/linux/cma.h | 4 ++--
include/linux/gfp.h | 2 +-
include/trace/events/cma.h | 22 +++++++++++-----------
mm/cma.c | 17 +++++++++--------
mm/page_alloc.c | 6 +++---
5 files changed, 26 insertions(+), 25 deletions(-)

diff --git a/include/linux/cma.h b/include/linux/cma.h
index 217999c8a762..53fd8c3cdbd0 100644
--- a/include/linux/cma.h
+++ b/include/linux/cma.h
@@ -44,9 +44,9 @@ extern int cma_init_reserved_mem(phys_addr_t base, phys_addr_t size,
unsigned int order_per_bit,
const char *name,
struct cma **res_cma);
-extern struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align,
+extern struct page *cma_alloc(struct cma *cma, unsigned long count, unsigned int align,
bool no_warn);
-extern bool cma_release(struct cma *cma, const struct page *pages, unsigned int count);
+extern bool cma_release(struct cma *cma, const struct page *pages, unsigned long count);
extern int cma_for_each_area(int (*it)(struct cma *cma, void *data), void *data);
#endif
diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index 0a88f84b08f4..529c27c6cb15 100644
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -639,7 +639,7 @@ extern int alloc_contig_range(unsigned long start, unsigned long end,
extern struct page *alloc_contig_pages(unsigned long nr_pages, gfp_t gfp_mask,
int nid, nodemask_t *nodemask);
#endif
-void free_contig_range(unsigned long pfn, unsigned int nr_pages);
+void free_contig_range(unsigned long pfn, unsigned long nr_pages);
#ifdef CONFIG_CMA
/* CMA stuff */
diff --git a/include/trace/events/cma.h b/include/trace/events/cma.h
index 5cf385ae7c08..c3d354702cb0 100644
--- a/include/trace/events/cma.h
+++ b/include/trace/events/cma.h
@@ -11,7 +11,7 @@
DECLARE_EVENT_CLASS(cma_alloc_class,
TP_PROTO(const char *name, unsigned long pfn, const struct page *page,
- unsigned int count, unsigned int align),
+ unsigned long count, unsigned int align),
TP_ARGS(name, pfn, page, count, align),
@@ -19,7 +19,7 @@ DECLARE_EVENT_CLASS(cma_alloc_class,
__string(name, name)
__field(unsigned long, pfn)
__field(const struct page *, page)
- __field(unsigned int, count)
+ __field(unsigned long, count)
__field(unsigned int, align)
),
@@ -31,7 +31,7 @@ DECLARE_EVENT_CLASS(cma_alloc_class,
__entry->align = align;
),
- TP_printk("name=%s pfn=%lx page=%p count=%u align=%u",
+ TP_printk("name=%s pfn=%lx page=%p count=%lu align=%u",
__get_str(name),
__entry->pfn,
__entry->page,
@@ -42,7 +42,7 @@ DECLARE_EVENT_CLASS(cma_alloc_class,
TRACE_EVENT(cma_release,
TP_PROTO(const char *name, unsigned long pfn, const struct page *page,
- unsigned int count),
+ unsigned long count),
TP_ARGS(name, pfn, page, count),
@@ -50,7 +50,7 @@ TRACE_EVENT(cma_release,
__string(name, name)
__field(unsigned long, pfn)
__field(const struct page *, page)
- __field(unsigned int, count)
+ __field(unsigned long, count)
),
TP_fast_assign(
@@ -60,7 +60,7 @@ TRACE_EVENT(cma_release,
__entry->count = count;
),
- TP_printk("name=%s pfn=%lx page=%p count=%u",
+ TP_printk("name=%s pfn=%lx page=%p count=%lu",
__get_str(name),
__entry->pfn,
__entry->page,
@@ -69,13 +69,13 @@ TRACE_EVENT(cma_release,
TRACE_EVENT(cma_alloc_start,
- TP_PROTO(const char *name, unsigned int count, unsigned int align),
+ TP_PROTO(const char *name, unsigned long count, unsigned int align),
TP_ARGS(name, count, align),
TP_STRUCT__entry(
__string(name, name)
- __field(unsigned int, count)
+ __field(unsigned long, count)
__field(unsigned int, align)
),
@@ -85,7 +85,7 @@ TRACE_EVENT(cma_alloc_start,
__entry->align = align;
),
- TP_printk("name=%s count=%u align=%u",
+ TP_printk("name=%s count=%lu align=%u",
__get_str(name),
__entry->count,
__entry->align)
@@ -94,7 +94,7 @@ TRACE_EVENT(cma_alloc_start,
DEFINE_EVENT(cma_alloc_class, cma_alloc_finish,
TP_PROTO(const char *name, unsigned long pfn, const struct page *page,
- unsigned int count, unsigned int align),
+ unsigned long count, unsigned int align),
TP_ARGS(name, pfn, page, count, align)
);
@@ -102,7 +102,7 @@ DEFINE_EVENT(cma_alloc_class, cma_alloc_finish,
DEFINE_EVENT(cma_alloc_class, cma_alloc_busy_retry,
TP_PROTO(const char *name, unsigned long pfn, const struct page *page,
- unsigned int count, unsigned int align),
+ unsigned long count, unsigned int align),
TP_ARGS(name, pfn, page, count, align)
);
diff --git a/mm/cma.c b/mm/cma.c
index de6b9f01be53..f3bca4178c7f 100644
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -80,7 +80,7 @@ static unsigned long cma_bitmap_pages_to_bits(const struct cma *cma,
}
static void cma_clear_bitmap(struct cma *cma, unsigned long pfn,
- unsigned int count)
+ unsigned long count)
{
unsigned long bitmap_no, bitmap_count;
@@ -423,21 +423,21 @@ static inline void cma_debug_show_areas(struct cma *cma) { }
* This function allocates part of contiguous memory on specific
* contiguous memory area.
*/
-struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align,
- bool no_warn)
+struct page *cma_alloc(struct cma *cma, unsigned long count,
+ unsigned int align, bool no_warn)
{
unsigned long mask, offset;
unsigned long pfn = -1;
unsigned long start = 0;
unsigned long bitmap_maxno, bitmap_no, bitmap_count;
- size_t i;
+ unsigned long i;
struct page *page = NULL;
int ret = -ENOMEM;
if (!cma || !cma->count || !cma->bitmap)
goto out;
- pr_debug("%s(cma %p, count %zu, align %d)\n", __func__, (void *)cma,
+ pr_debug("%s(cma %p, count %lu, align %d)\n", __func__, (void *)cma,
count, align);
if (!count)
@@ -505,7 +505,7 @@ struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align,
}
if (ret && !no_warn) {
- pr_err_ratelimited("%s: %s: alloc failed, req-size: %zu pages, ret: %d\n",
+ pr_err_ratelimited("%s: %s: alloc failed, req-size: %lu pages, ret: %d\n",
__func__, cma->name, count, ret);
cma_debug_show_areas(cma);
}
@@ -534,14 +534,15 @@ struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align,
* It returns false when provided pages do not belong to contiguous area and
* true otherwise.
*/
-bool cma_release(struct cma *cma, const struct page *pages, unsigned int count)
+bool cma_release(struct cma *cma, const struct page *pages,
+ unsigned long count)
{
unsigned long pfn;
if (!cma || !pages)
return false;
- pr_debug("%s(page %p, count %u)\n", __func__, (void *)pages, count);
+ pr_debug("%s(page %p, count %lu)\n", __func__, (void *)pages, count);
pfn = page_to_pfn(pages);
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index c53fe4fa10bf..21540fb29b0d 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -8817,9 +8817,9 @@ struct page *alloc_contig_pages(unsigned long nr_pages, gfp_t gfp_mask,
}
#endif /* CONFIG_CONTIG_ALLOC */
-void free_contig_range(unsigned long pfn, unsigned int nr_pages)
+void free_contig_range(unsigned long pfn, unsigned long nr_pages)
{
- unsigned int count = 0;
+ unsigned long count = 0;
for (; nr_pages--; pfn++) {
struct page *page = pfn_to_page(pfn);
@@ -8827,7 +8827,7 @@ void free_contig_range(unsigned long pfn, unsigned int nr_pages)
count += page_count(page) != 1;
__free_page(page);
}
- WARN(count != 0, "%d pages are still in use!\n", count);
+ WARN(count != 0, "%lu pages are still in use!\n", count);
}
EXPORT_SYMBOL(free_contig_range);


Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>

--
Thanks,

David / dhildenb