(6/22/12 10:35 AM), Nathan Zimmer wrote:
> When tmpfs has the memory policy interleaved it always starts allocating at each
> file at node 0. When there are many small files the lower nodes fill up
> disproportionately.
> This patch attempts to spread out node usage by starting files at nodes other
> then 0. I disturbed the addr parameter since alloc_pages_vma will only use it
> when the policy is MPOL_INTERLEAVE. A files preferred node is selected by
> the cpu_mem_spread_node rotor.
>
> v2: passed preferred node via addr
> v3: using current->cpuset_mem_spread_rotor instead of random_node
>
> Cc: Christoph Lameter <cl@xxxxxxxxx>
> Cc: Nick Piggin <npiggin@xxxxxxxxx>
> Cc: Hugh Dickins <hughd@xxxxxxxxxx>
> Cc: Lee Schermerhorn <lee.schermerhorn@xxxxxx>
> Cc: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
> Acked-by: Rik van Riel <riel@xxxxxxxxxx>
> Signed-off-by: Nathan T Zimmer <nzimmer@xxxxxxx>
> ---
>
> include/linux/shmem_fs.h | 1 +
> mm/shmem.c | 9 +++++++--
> 2 files changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h
> index bef2cf0..cfe8a34 100644
> --- a/include/linux/shmem_fs.h
> +++ b/include/linux/shmem_fs.h
> @@ -17,6 +17,7 @@ struct shmem_inode_info {
> char *symlink; /* unswappable short symlink */
> };
> struct shared_policy policy; /* NUMA memory alloc policy */
> + unsigned long node_offset; /* bias for interleaved nodes */
> struct list_head swaplist; /* chain of maybes on swap */
> struct list_head xattr_list; /* list of shmem_xattr */
> struct inode vfs_inode;
> diff --git a/mm/shmem.c b/mm/shmem.c
> index a15a466..93801b3 100644
> --- a/mm/shmem.c
> +++ b/mm/shmem.c
> @@ -64,6 +64,7 @@ static struct vfsmount *shm_mnt;
> #include <linux/highmem.h>
> #include <linux/seq_file.h>
> #include <linux/magic.h>
> +#include <linux/cpuset.h>
>
> #include <asm/uaccess.h>
> #include <asm/pgtable.h>
> @@ -938,9 +939,12 @@ static struct page *shmem_alloc_page(gfp_t gfp,
> pvma.vm_policy = mpol_shared_policy_lookup(&info->policy, index);
>
> /*
> - * alloc_page_vma() will drop the shared policy reference
> + * alloc_page_vma() will drop the shared policy reference.
> + *
> + * To avoid allocating all tmpfs pages on node 0, we fake up a virtual
> + * address based on this file's predetermined preferred node.
> */
> - return alloc_page_vma(gfp, &pvma, 0);
> + return alloc_page_vma(gfp, &pvma, info->node_offset << PAGE_SHIFT);
Still unacceptable. Please stop to pass hacky fake address.
> }
> #else /* !CONFIG_NUMA */
> #ifdef CONFIG_TMPFS
> @@ -1374,6 +1378,7 @@ static struct inode *shmem_get_inode(struct super_block *sb, const struct inode
> inode->i_fop = &shmem_file_operations;
> mpol_shared_policy_init(&info->policy,
> shmem_get_sbmpol(sbinfo));
> + info->node_offset = cpuset_mem_spread_node();
cpuset_mem_spread_node is designed for using allocation time.
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>