| Message ID | 20210329182553.3129234-1-minchan@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | mm: change size_t to unsigned int for cma_alloc | expand |
On Mon, Mar 29, 2021 at 11:25:53AM -0700, Minchan Kim wrote: > size_t in cma_alloc is confusing since it makes people think > it's byte count, not pages. Fix it. i think it has to be unsigned long. 67a2e213e7e937c41c52ab5bc46bf3f4de469f6e > Link: https://lore.kernel.org/linux-mm/20210324043434.GP1719932@casper.infradead.org/ > Cc: Matthew Wilcox <willy@infradead.org> > Signed-off-by: Minchan Kim <minchan@kernel.org> > --- > include/linux/cma.h | 2 +- > mm/cma.c | 8 ++++---- > 2 files changed, 5 insertions(+), 5 deletions(-) > > diff --git a/include/linux/cma.h b/include/linux/cma.h > index 217999c8a762..a873edc20ca2 100644 > --- a/include/linux/cma.h > +++ b/include/linux/cma.h > @@ -44,7 +44,7 @@ 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 int count, unsigned int align, > bool no_warn); > extern bool cma_release(struct cma *cma, const struct page *pages, unsigned int count); > > diff --git a/mm/cma.c b/mm/cma.c > index 08c45157911a..24dc01e26d45 100644 > --- a/mm/cma.c > +++ b/mm/cma.c > @@ -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, > +struct page *cma_alloc(struct cma *cma, unsigned int 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 int 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 %u, align %d)\n", __func__, (void *)cma, > count, align); > > if (!count) > @@ -500,7 +500,7 @@ 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: %u pages, ret: %d\n", > __func__, cma->name, count, ret); > cma_debug_show_areas(cma); > } > -- > 2.31.0.291.g576ba9dcdaf-goog > >
On Mon, Mar 29, 2021 at 07:44:31PM +0100, Matthew Wilcox wrote: > On Mon, Mar 29, 2021 at 11:25:53AM -0700, Minchan Kim wrote: > > size_t in cma_alloc is confusing since it makes people think > > it's byte count, not pages. Fix it. > > i think it has to be unsigned long. > > 67a2e213e7e937c41c52ab5bc46bf3f4de469f6e Thanks for the pinter. I wanted to have the smallest change. The commit leads me to change cma_release, trace_cma_alloc, cma_clear_bitmap and front_contig_range as well.(Not sure we have more. Will check). Ccing david@redhat.com for upcoming changing free_contig_range. > > > Link: https://lore.kernel.org/linux-mm/20210324043434.GP1719932@casper.infradead.org/ > > Cc: Matthew Wilcox <willy@infradead.org> > > Signed-off-by: Minchan Kim <minchan@kernel.org> > > --- > > include/linux/cma.h | 2 +- > > mm/cma.c | 8 ++++---- > > 2 files changed, 5 insertions(+), 5 deletions(-) > > > > diff --git a/include/linux/cma.h b/include/linux/cma.h > > index 217999c8a762..a873edc20ca2 100644 > > --- a/include/linux/cma.h > > +++ b/include/linux/cma.h > > @@ -44,7 +44,7 @@ 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 int count, unsigned int align, > > bool no_warn); > > extern bool cma_release(struct cma *cma, const struct page *pages, unsigned int count); > > > > diff --git a/mm/cma.c b/mm/cma.c > > index 08c45157911a..24dc01e26d45 100644 > > --- a/mm/cma.c > > +++ b/mm/cma.c > > @@ -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, > > +struct page *cma_alloc(struct cma *cma, unsigned int 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 int 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 %u, align %d)\n", __func__, (void *)cma, > > count, align); > > > > if (!count) > > @@ -500,7 +500,7 @@ 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: %u pages, ret: %d\n", > > __func__, cma->name, count, ret); > > cma_debug_show_areas(cma); > > } > > -- > > 2.31.0.291.g576ba9dcdaf-goog > > > >
On 29.03.21 22:12, Minchan Kim wrote: > On Mon, Mar 29, 2021 at 07:44:31PM +0100, Matthew Wilcox wrote: >> On Mon, Mar 29, 2021 at 11:25:53AM -0700, Minchan Kim wrote: >>> size_t in cma_alloc is confusing since it makes people think >>> it's byte count, not pages. Fix it. >> >> i think it has to be unsigned long. >> >> 67a2e213e7e937c41c52ab5bc46bf3f4de469f6e Right. Fortunately, we don't have such large allocations yet via CMA/alloc_contig_range > > Thanks for the pinter. I wanted to have the smallest change. > The commit leads me to change cma_release, trace_cma_alloc, > cma_clear_bitmap and front_contig_range as well.(Not sure > we have more. Will check). > > Ccing david@redhat.com for upcoming changing free_contig_range. While at it, we might want to convert free_contig_range() to eat "unsigned long start, unsigned long end" like alloc_contig_range(), instead of "unsigned long pfn, unsigned int nr_pages" like alloc_contig_pages() ...
On Tue, Mar 30, 2021 at 09:58:37AM +0200, David Hildenbrand wrote: > On 29.03.21 22:12, Minchan Kim wrote: > > On Mon, Mar 29, 2021 at 07:44:31PM +0100, Matthew Wilcox wrote: > > > On Mon, Mar 29, 2021 at 11:25:53AM -0700, Minchan Kim wrote: > > > > size_t in cma_alloc is confusing since it makes people think > > > > it's byte count, not pages. Fix it. > > > > > > i think it has to be unsigned long. > > > > > > 67a2e213e7e937c41c52ab5bc46bf3f4de469f6e > > Right. > > Fortunately, we don't have such large allocations yet via > CMA/alloc_contig_range > > > > > Thanks for the pinter. I wanted to have the smallest change. > > The commit leads me to change cma_release, trace_cma_alloc, > > cma_clear_bitmap and front_contig_range as well.(Not sure > > we have more. Will check). > > > > Ccing david@redhat.com for upcoming changing free_contig_range. > > While at it, we might want to convert free_contig_range() to eat > "unsigned long start, unsigned long end" like alloc_contig_range(), instead > of "unsigned long pfn, unsigned int nr_pages" like alloc_contig_pages() ... Well, I personllay tempted to change alloc_contig_range, not free_contig_range because base_pfn with nr_pages was more straightforward than base_pfn and end_pfn in that we don't need to tell whether end_pfn is inclusive or exclusive. When I look at callers of [alloc|free]_contig_range, many of them already have used nr_pages based approach rather than start_pfn, end_pfn. If your suggestion come from that "it's *range* API", I'd like to rename it with "alloc_contig_pages|free_contig_pages". Since it's beyond the goal of this patch and might be controversial, I will not deal with it in this patch.
On 30.03.21 17:00, Minchan Kim wrote: > On Tue, Mar 30, 2021 at 09:58:37AM +0200, David Hildenbrand wrote: >> On 29.03.21 22:12, Minchan Kim wrote: >>> On Mon, Mar 29, 2021 at 07:44:31PM +0100, Matthew Wilcox wrote: >>>> On Mon, Mar 29, 2021 at 11:25:53AM -0700, Minchan Kim wrote: >>>>> size_t in cma_alloc is confusing since it makes people think >>>>> it's byte count, not pages. Fix it. >>>> >>>> i think it has to be unsigned long. >>>> >>>> 67a2e213e7e937c41c52ab5bc46bf3f4de469f6e >> >> Right. >> >> Fortunately, we don't have such large allocations yet via >> CMA/alloc_contig_range >> >>> >>> Thanks for the pinter. I wanted to have the smallest change. >>> The commit leads me to change cma_release, trace_cma_alloc, >>> cma_clear_bitmap and front_contig_range as well.(Not sure >>> we have more. Will check). >>> >>> Ccing david@redhat.com for upcoming changing free_contig_range. >> >> While at it, we might want to convert free_contig_range() to eat >> "unsigned long start, unsigned long end" like alloc_contig_range(), instead >> of "unsigned long pfn, unsigned int nr_pages" like alloc_contig_pages() ... > > Well, I personllay tempted to change alloc_contig_range, not > free_contig_range because base_pfn with nr_pages was more > straightforward than base_pfn and end_pfn in that we don't > need to tell whether end_pfn is inclusive or exclusive. > That's right. > When I look at callers of [alloc|free]_contig_range, many of them > already have used nr_pages based approach rather than start_pfn, > end_pfn. If your suggestion come from that "it's *range* API", Right you are, teaching alloc_contig_range() to eat "nr_pages" might actually be even better and more consistent. > I'd like to rename it with "alloc_contig_pages|free_contig_pages". alloc_contig_pages is just a wrapper for alloc_contig_range(), so free_contig_range() is a better fit; OTOH, having both would also somehow make sense. > > Since it's beyond the goal of this patch and might be controversial, > I will not deal with it in this patch. Sure, but feel free to send a patch to make that consistent. It's been bugging me already (having to always remember if to pass in nr_pages or end).
diff --git a/include/linux/cma.h b/include/linux/cma.h index 217999c8a762..a873edc20ca2 100644 --- a/include/linux/cma.h +++ b/include/linux/cma.h @@ -44,7 +44,7 @@ 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 int count, unsigned int align, bool no_warn); extern bool cma_release(struct cma *cma, const struct page *pages, unsigned int count); diff --git a/mm/cma.c b/mm/cma.c index 08c45157911a..24dc01e26d45 100644 --- a/mm/cma.c +++ b/mm/cma.c @@ -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, +struct page *cma_alloc(struct cma *cma, unsigned int 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 int 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 %u, align %d)\n", __func__, (void *)cma, count, align); if (!count) @@ -500,7 +500,7 @@ 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: %u pages, ret: %d\n", __func__, cma->name, count, ret); cma_debug_show_areas(cma); }
size_t in cma_alloc is confusing since it makes people think it's byte count, not pages. Fix it. Link: https://lore.kernel.org/linux-mm/20210324043434.GP1719932@casper.infradead.org/ Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Minchan Kim <minchan@kernel.org> --- include/linux/cma.h | 2 +- mm/cma.c | 8 ++++---- 2 files changed, 5 insertions(+), 5 deletions(-)