kevin/linux
1
Fork 0
Code

iommu: account IOMMU allocated memory

Browse Source 
In order to be able to limit the amount of memory that is allocated
by IOMMU subsystem, the memory must be accounted.

Account IOMMU as part of the secondary pagetables as it was discussed
at LPC.

The value of SecPageTables now contains mmeory allocation by IOMMU
and KVM.

There is a difference between GFP_ACCOUNT and what NR_IOMMU_PAGES shows.
GFP_ACCOUNT is set only where it makes sense to charge to user
processes, i.e. IOMMU Page Tables, but there more IOMMU shared data
that should not really be charged to a specific process.

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/20240413002522.1101315-12-pasha.tatashin@soleen.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
This commit is contained in:
Pasha Tatashin 2024-04-13 00:25:22 +00:00 committed by Joerg Roedel
parent bd3520a93a
commit 212c5c078d
4 changed files with 6 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
Documentation/admin-guide/cgroup-v2.rst
View File

@ -1432,7 +1432,7 @@ PAGE_SIZE multiple when read back.
sec_pagetables
Amount of memory allocated for secondary page tables,
this currently includes KVM mmu allocations on x86
and arm64.
and arm64 and IOMMU page tables.
percpu (npn)
Amount of memory used for storing per-cpu kernel

4
Documentation/filesystems/proc.rst
View File

@ -1110,8 +1110,8 @@ KernelStack
PageTables
Memory consumed by userspace page tables
SecPageTables
Memory consumed by secondary page tables, this currently
currently includes KVM mmu allocations on x86 and arm64.
Memory consumed by secondary page tables, this currently includes
KVM mmu and IOMMU allocations on x86 and arm64.
NFS_Unstable
Always zero. Previous counted pages which had been written to
the server, but has not been committed to stable storage.

2
drivers/iommu/iommu-pages.h
View File

@ -30,6 +30,7 @@ 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);
mod_lruvec_page_state(page, NR_SECONDARY_PAGETABLE, pgcnt);
}
/**
@ -42,6 +43,7 @@ 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);
mod_lruvec_page_state(page, NR_SECONDARY_PAGETABLE, -pgcnt);
}
/**

2
include/linux/mmzone.h
View File

@ -205,7 +205,7 @@ enum node_stat_item {
NR_KERNEL_SCS_KB, /* measured in KiB */
#endif
NR_PAGETABLE, /* used for pagetables */
NR_SECONDARY_PAGETABLE, /* secondary pagetables, e.g. KVM pagetables */
NR_SECONDARY_PAGETABLE, /* secondary pagetables, KVM & IOMMU */
#ifdef CONFIG_IOMMU_SUPPORT
NR_IOMMU_PAGES, /* # of pages allocated by IOMMU */
#endif