diff mbox series

[13/16] iommu: observability of the IOMMU allocations

Message ID 20231128204938.1453583-14-pasha.tatashin@soleen.com
State Superseded
Headers show
Series IOMMU memory observability | expand

Commit Message

Pasha Tatashin Nov. 28, 2023, 8:49 p.m. UTC
Add NR_IOMMU_PAGES into node_stat_item that counts number of pages
that are allocated by the IOMMU subsystem.

The allocations can be view per-node via:
/sys/devices/system/node/nodeN/vmstat.

For example:

$ grep iommu /sys/devices/system/node/node*/vmstat
/sys/devices/system/node/node0/vmstat:nr_iommu_pages 106025
/sys/devices/system/node/node1/vmstat:nr_iommu_pages 3464

The value is in page-count, therefore, in the above example
the iommu allocations amount to ~428M.

Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
---
 drivers/iommu/iommu-pages.h | 30 ++++++++++++++++++++++++++++++
 include/linux/mmzone.h      |  3 +++
 mm/vmstat.c                 |  3 +++
 3 files changed, 36 insertions(+)

Comments

kernel test robot Nov. 30, 2023, 2:03 p.m. UTC | #1
Hi Pasha,

kernel test robot noticed the following build errors:

[auto build test ERROR on akpm-mm/mm-everything]
[also build test ERROR on awilliam-vfio/for-linus linus/master v6.7-rc3]
[cannot apply to joro-iommu/next awilliam-vfio/next next-20231130]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Pasha-Tatashin/iommu-vt-d-add-wrapper-functions-for-page-allocations/20231129-054908
base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link:    https://lore.kernel.org/r/20231128204938.1453583-14-pasha.tatashin%40soleen.com
patch subject: [PATCH 13/16] iommu: observability of the IOMMU allocations
config: sparc64-randconfig-r054-20231130 (https://download.01.org/0day-ci/archive/20231130/202311302108.WERv9oSO-lkp@intel.com/config)
compiler: sparc64-linux-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231130/202311302108.WERv9oSO-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202311302108.WERv9oSO-lkp@intel.com/

All errors (new ones prefixed by >>):

   In file included from drivers/iommu/iommufd/iova_bitmap.c:11:
   drivers/iommu/iommufd/../iommu-pages.h: In function '__iommu_alloc_account':
>> drivers/iommu/iommufd/../iommu-pages.h:29:48: error: 'NR_IOMMU_PAGES' undeclared (first use in this function)
      29 |         mod_node_page_state(page_pgdat(pages), NR_IOMMU_PAGES, pgcnt);
         |                                                ^~~~~~~~~~~~~~
   drivers/iommu/iommufd/../iommu-pages.h:29:48: note: each undeclared identifier is reported only once for each function it appears in
   drivers/iommu/iommufd/../iommu-pages.h: In function '__iommu_free_account':
   drivers/iommu/iommufd/../iommu-pages.h:41:48: error: 'NR_IOMMU_PAGES' undeclared (first use in this function)
      41 |         mod_node_page_state(page_pgdat(pages), NR_IOMMU_PAGES, -pgcnt);
         |                                                ^~~~~~~~~~~~~~


vim +/NR_IOMMU_PAGES +29 drivers/iommu/iommufd/../iommu-pages.h

    13	
    14	/*
    15	 * All page allocation that are performed in the IOMMU subsystem must use one of
    16	 * the functions below.  This is necessary for the proper accounting as IOMMU
    17	 * state can be rather large, i.e. multiple gigabytes in size.
    18	 */
    19	
    20	/**
    21	 * __iommu_alloc_account - account for newly allocated page.
    22	 * @pages: head struct page of the page.
    23	 * @order: order of the page
    24	 */
    25	static inline void __iommu_alloc_account(struct page *pages, int order)
    26	{
    27		const long pgcnt = 1l << order;
    28	
  > 29		mod_node_page_state(page_pgdat(pages), NR_IOMMU_PAGES, pgcnt);
    30	}
    31
diff mbox series

Patch

diff --git a/drivers/iommu/iommu-pages.h b/drivers/iommu/iommu-pages.h
index 2332f807d514..69895a355c0c 100644
--- a/drivers/iommu/iommu-pages.h
+++ b/drivers/iommu/iommu-pages.h
@@ -17,6 +17,30 @@ 
  * state can be rather large, i.e. multiple gigabytes in size.
  */
 
+/**
+ * __iommu_alloc_account - account for newly allocated page.
+ * @pages: head struct page of the page.
+ * @order: order of the page
+ */
+static inline void __iommu_alloc_account(struct page *pages, int order)
+{
+	const long pgcnt = 1l << order;
+
+	mod_node_page_state(page_pgdat(pages), NR_IOMMU_PAGES, pgcnt);
+}
+
+/**
+ * __iommu_free_account - account a page that is about to be freed.
+ * @pages: head struct page of the page.
+ * @order: order of the page
+ */
+static inline void __iommu_free_account(struct page *pages, int order)
+{
+	const long pgcnt = 1l << order;
+
+	mod_node_page_state(page_pgdat(pages), NR_IOMMU_PAGES, -pgcnt);
+}
+
 /**
  * __iommu_alloc_pages_node - allocate a zeroed page of a given order from
  * specific NUMA node.
@@ -35,6 +59,8 @@  static inline struct page *__iommu_alloc_pages_node(int nid, gfp_t gfp,
 	if (!pages)
 		return NULL;
 
+	__iommu_alloc_account(pages, order);
+
 	return pages;
 }
 
@@ -53,6 +79,8 @@  static inline struct page *__iommu_alloc_pages(gfp_t gfp, int order)
 	if (!pages)
 		return NULL;
 
+	__iommu_alloc_account(pages, order);
+
 	return pages;
 }
 
@@ -89,6 +117,7 @@  static inline void __iommu_free_pages(struct page *pages, int order)
 	if (!pages)
 		return;
 
+	__iommu_free_account(pages, order);
 	__free_pages(pages, order);
 }
 
@@ -192,6 +221,7 @@  static inline void iommu_free_pages_list(struct list_head *pages)
 		struct page *p = list_entry(pages->prev, struct page, lru);
 
 		list_del(&p->lru);
+		__iommu_free_account(p, 0);
 		put_page(p);
 	}
 }
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 3c25226beeed..1a4d0bba3e8b 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -200,6 +200,9 @@  enum node_stat_item {
 #endif
 	NR_PAGETABLE,		/* used for pagetables */
 	NR_SECONDARY_PAGETABLE, /* secondary pagetables, e.g. KVM pagetables */
+#ifdef CONFIG_IOMMU_SUPPORT
+	NR_IOMMU_PAGES,		/* # of pages allocated by IOMMU */
+#endif
 #ifdef CONFIG_SWAP
 	NR_SWAPCACHE,
 #endif
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 359460deb377..801b58890b6c 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1242,6 +1242,9 @@  const char * const vmstat_text[] = {
 #endif
 	"nr_page_table_pages",
 	"nr_sec_page_table_pages",
+#ifdef CONFIG_IOMMU_SUPPORT
+	"nr_iommu_pages",
+#endif
 #ifdef CONFIG_SWAP
 	"nr_swapcached",
 #endif