iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

iommu: observability of the IOMMU allocations

Browse Source 
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>
Acked-by: David Rientjes <rientjes@google.com>
Tested-by: Bagas Sanjaya <bagasdotme@gmail.com>
Link: https://lore.kernel.org/r/20240413002522.1101315-11-pasha.tatashin@soleen.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
This commit is contained in:
Pasha Tatashin 2024-04-13 00:25:21 +00:00 committed by Joerg Roedel
parent 8e8b4ac5b0
commit bd3520a93a
3 changed files with 36 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

30
drivers/iommu/iommu-pages.h
View File

@ -20,6 +20,30 @@
* large, i.e. multiple gigabytes in size.
*/
/**
* __iommu_alloc_account - account for newly allocated page.
* @page: head struct page of the page.
* @order: order of the page
*/
static inline void __iommu_alloc_account(struct page *page, int order)
{
const long pgcnt = 1l << order;
mod_node_page_state(page_pgdat(page), NR_IOMMU_PAGES, pgcnt);
}
/**
* __iommu_free_account - account a page that is about to be freed.
* @page: head struct page of the page.
* @order: order of the page
*/
static inline void __iommu_free_account(struct page *page, int order)
{
const long pgcnt = 1l << order;
mod_node_page_state(page_pgdat(page), NR_IOMMU_PAGES, -pgcnt);
}
/**
* __iommu_alloc_pages - allocate a zeroed page of a given order.
* @gfp: buddy allocator flags
@ -35,6 +59,8 @@ static inline struct page *__iommu_alloc_pages(gfp_t gfp, int order)
if (unlikely(!page))
return NULL;
__iommu_alloc_account(page, order);
return page;
}
@ -48,6 +74,7 @@ static inline void __iommu_free_pages(struct page *page, int order)
if (!page)
return;
__iommu_free_account(page, order);
__free_pages(page, order);
}
@ -67,6 +94,8 @@ static inline void *iommu_alloc_pages_node(int nid, gfp_t gfp, int order)
if (unlikely(!page))
return NULL;
__iommu_alloc_account(page, order);
return page_address(page);
}
@ -147,6 +176,7 @@ static inline void iommu_put_pages_list(struct list_head *page)
struct page *p = list_entry(page->prev, struct page, lru);
list_del(&p->lru);
__iommu_free_account(p, 0);
put_page(p);
}
}

3
include/linux/mmzone.h
View File

@ -206,6 +206,9 @@ 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

3
mm/vmstat.c
View File

@ -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