| Message ID | 20220112193340.149020-2-hbathini@linux.ibm.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | powerpc/fadump: handle CMA activation failure appropriately | expand |
> +{ > + if (!cma) > + return; Do we really need that check for NULL? > + > + cma->reserve_pages_on_error = true; > +} > + > /** > * cma_init_reserved_mem() - create custom contiguous area from reserved memory > * @base: Base address of the reserved area > @@ -204,6 +214,7 @@ int __init cma_init_reserved_mem(phys_addr_t base, phys_addr_t size, > cma->base_pfn = PFN_DOWN(base); > cma->count = size >> PAGE_SHIFT; > cma->order_per_bit = order_per_bit; > + cma->reserve_pages_on_error = false; I think you can drop that; should already be initialized to 0. Apart from that Reviewed-by: David Hildenbrand <david@redhat.com>
On 13/01/22 2:00 pm, David Hildenbrand wrote: >> +{ >> + if (!cma) >> + return; > > Do we really need that check for NULL? Probably not. > >> + >> + cma->reserve_pages_on_error = true; >> +} >> + >> /** >> * cma_init_reserved_mem() - create custom contiguous area from reserved memory >> * @base: Base address of the reserved area >> @@ -204,6 +214,7 @@ int __init cma_init_reserved_mem(phys_addr_t base, phys_addr_t size, >> cma->base_pfn = PFN_DOWN(base); >> cma->count = size >> PAGE_SHIFT; >> cma->order_per_bit = order_per_bit; >> + cma->reserve_pages_on_error = false; > > I think you can drop that; should already be initialized to 0. > > > Apart from that > > Reviewed-by: David Hildenbrand <david@redhat.com> > Thanks for the review, David. Posted v3 with the changes suggested above. - Hari
diff --git a/include/linux/cma.h b/include/linux/cma.h index bd801023504b..51d540eee18a 100644 --- a/include/linux/cma.h +++ b/include/linux/cma.h @@ -50,4 +50,6 @@ extern bool cma_pages_valid(struct cma *cma, const struct page *pages, unsigned 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); + +extern void cma_reserve_pages_on_error(struct cma *cma); #endif diff --git a/mm/cma.c b/mm/cma.c index bc9ca8f3c487..20626321f87f 100644 --- a/mm/cma.c +++ b/mm/cma.c @@ -131,8 +131,10 @@ static void __init cma_activate_area(struct cma *cma) bitmap_free(cma->bitmap); out_error: /* Expose all pages to the buddy, they are useless for CMA. */ - for (pfn = base_pfn; pfn < base_pfn + cma->count; pfn++) - free_reserved_page(pfn_to_page(pfn)); + if (!cma->reserve_pages_on_error) { + for (pfn = base_pfn; pfn < base_pfn + cma->count; pfn++) + free_reserved_page(pfn_to_page(pfn)); + } totalcma_pages -= cma->count; cma->count = 0; pr_err("CMA area %s could not be activated\n", cma->name); @@ -150,6 +152,14 @@ static int __init cma_init_reserved_areas(void) } core_initcall(cma_init_reserved_areas); +void __init cma_reserve_pages_on_error(struct cma *cma) +{ + if (!cma) + return; + + cma->reserve_pages_on_error = true; +} + /** * cma_init_reserved_mem() - create custom contiguous area from reserved memory * @base: Base address of the reserved area @@ -204,6 +214,7 @@ int __init cma_init_reserved_mem(phys_addr_t base, phys_addr_t size, cma->base_pfn = PFN_DOWN(base); cma->count = size >> PAGE_SHIFT; cma->order_per_bit = order_per_bit; + cma->reserve_pages_on_error = false; *res_cma = cma; cma_area_count++; totalcma_pages += (size / PAGE_SIZE); diff --git a/mm/cma.h b/mm/cma.h index 2c775877eae2..88a0595670b7 100644 --- a/mm/cma.h +++ b/mm/cma.h @@ -30,6 +30,7 @@ struct cma { /* kobject requires dynamic object */ struct cma_kobject *cma_kobj; #endif + bool reserve_pages_on_error; }; extern struct cma cma_areas[MAX_CMA_AREAS];
Commit 072355c1cf2d ("mm/cma: expose all pages to the buddy if activation of an area fails") started exposing all pages to buddy allocator on CMA activation failure. But there can be CMA users that want to handle the reserved memory differently on CMA allocation failure. Provide an option to opt out from exposing pages to buddy for such cases. Signed-off-by: Hari Bathini <hbathini@linux.ibm.com> --- Changes in v2: * Changed cma->free_pages_on_error to cma->reserve_pages_on_error and cma_dont_free_pages_on_error() to cma_reserve_pages_on_error() to avoid cofusion. include/linux/cma.h | 2 ++ mm/cma.c | 15 +++++++++++++-- mm/cma.h | 1 + 3 files changed, 16 insertions(+), 2 deletions(-)