Patch "mm: cma: split cma-reserved in dmesg log" has been added to the 3.18-stable tree

This is a note to let you know that I've just added the patch titled

mm: cma: split cma-reserved in dmesg log

to the 3.18-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
mm-cma-split-cma-reserved-in-dmesg-log.patch
and it can be found in the queue-3.18 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Pintu Kumar <[email protected]>
Date: Thu, 18 Dec 2014 16:17:15 -0800
Subject: mm: cma: split cma-reserved in dmesg log

From: Pintu Kumar <[email protected]>

commit e48322abb061d75096fe52d71886b237e7ae7bfb upstream.

When the system boots up, in the dmesg logs we can see the memory statistics along with total reserved as below. Memory: 458840k/458840k available, 65448k reserved, 0K highmem

When CMA is enabled, still the total reserved memory remains the same. However, the CMA memory is not considered as reserved. But, when we see /proc/meminfo, the CMA memory is part of free memory. This creates confusion. This patch corrects the problem by properly subtracting the CMA reserved memory from the total reserved memory in dmesg logs.

Below is the dmesg snapshot from an arm based device with 512MB RAM and 12MB single CMA region.

Before this change:
Memory: 458840k/458840k available, 65448k reserved, 0K highmem

After this change:
Memory: 458840k/458840k available, 53160k reserved, 12288k cma-reserved, 0K highmem

---
 include/linux/cma.h |    1 +
 mm/cma.c            |    1 +
 mm/page_alloc.c     |    6 ++++--
 3 files changed, 6 insertions(+), 2 deletions(-)

@@ -15,6 +15,7 @@
 
 struct cma;
 
+extern unsigned long totalcma_pages;
 extern phys_addr_t cma_get_base(struct cma *cma);
 extern unsigned long cma_get_size(struct cma *cma);
 

@@ -338,6 +338,7 @@ int __init cma_declare_contiguous(phys_a
 	if (ret)
 		goto err;
 
+	totalcma_pages += (size / PAGE_SIZE);
 	pr_info("Reserved %ld MiB at %pa\n", (unsigned long)size / SZ_1M,
 		&base);
 	return 0;

@@ -110,6 +110,7 @@ static DEFINE_SPINLOCK(managed_page_coun
 
 unsigned long totalram_pages __read_mostly;
 unsigned long totalreserve_pages __read_mostly;
+unsigned long totalcma_pages __read_mostly;
 /*
  * When calculating the number of globally allowed dirty pages, there
  * is a certain number of per-zone reserves that should not be

@@ -5522,7 +5523,7 @@ void __init mem_init_print_info(const ch
 
 	printk("Memory: %luK/%luK available "
 	       "(%luK kernel code, %luK rwdata, %luK rodata, "
-	       "%luK init, %luK bss, %luK reserved"
+	       "%luK init, %luK bss, %luK reserved, %luK cma-reserved"
 #ifdef	CONFIG_HIGHMEM
 	       ", %luK highmem"
 #endif

@@ -5530,7 +5531,8 @@ void __init mem_init_print_info(const ch
 	       nr_free_pages() << (PAGE_SHIFT-10), physpages << (PAGE_SHIFT-10),
 	       codesize >> 10, datasize >> 10, rosize >> 10,
 	       (init_data_size + init_code_size) >> 10, bss_size >> 10,
-	       (physpages - totalram_pages) << (PAGE_SHIFT-10),
+	       (physpages - totalram_pages - totalcma_pages) << (PAGE_SHIFT-10),
+	       totalcma_pages << (PAGE_SHIFT-10),
 #ifdef	CONFIG_HIGHMEM
 	       totalhigh_pages << (PAGE_SHIFT-10),
 #endif

Patches currently in stable-queue which might be from [email protected] are

queue-3.18/mm-cma-split-cma-reserved-in-dmesg-log.patch queue-3.18/mm-cma-constify-and-use-correct-signness-in-mm-cma.c.patch