Re: [PATCH -mmotm 3/3] memcg: dirty pages instrumentation

From: Vivek Goyal
Date: Mon Mar 01 2010 - 17:03:41 EST

On Mon, Mar 01, 2010 at 10:23:40PM +0100, Andrea Righi wrote:
> Apply the cgroup dirty pages accounting and limiting infrastructure to
> the opportune kernel functions.
>
> Signed-off-by: Andrea Righi <arighi@xxxxxxxxxxx>
> ---
> fs/fuse/file.c | 5 +++
> fs/nfs/write.c | 4 ++
> fs/nilfs2/segment.c | 10 +++++-
> mm/filemap.c | 1 +
> mm/page-writeback.c | 84 ++++++++++++++++++++++++++++++++------------------
> mm/rmap.c | 4 +-
> mm/truncate.c | 2 +
> 7 files changed, 76 insertions(+), 34 deletions(-)
>
> diff --git a/fs/fuse/file.c b/fs/fuse/file.c
> index a9f5e13..dbbdd53 100644
> --- a/fs/fuse/file.c
> +++ b/fs/fuse/file.c
> @@ -11,6 +11,7 @@
> #include <linux/pagemap.h>
> #include <linux/slab.h>
> #include <linux/kernel.h>
> +#include <linux/memcontrol.h>
> #include <linux/sched.h>
> #include <linux/module.h>
>
> @@ -1129,6 +1130,8 @@ static void fuse_writepage_finish(struct fuse_conn *fc, struct fuse_req *req)
>
> list_del(&req->writepages_entry);
> dec_bdi_stat(bdi, BDI_WRITEBACK);
> + mem_cgroup_update_stat(req->pages[0],
> + MEM_CGROUP_STAT_WRITEBACK_TEMP, -1);
> dec_zone_page_state(req->pages[0], NR_WRITEBACK_TEMP);
> bdi_writeout_inc(bdi);
> wake_up(&fi->page_waitq);
> @@ -1240,6 +1243,8 @@ static int fuse_writepage_locked(struct page *page)
> req->inode = inode;
>
> inc_bdi_stat(mapping->backing_dev_info, BDI_WRITEBACK);
> + mem_cgroup_update_stat(tmp_page,
> + MEM_CGROUP_STAT_WRITEBACK_TEMP, 1);
> inc_zone_page_state(tmp_page, NR_WRITEBACK_TEMP);
> end_page_writeback(page);
>
> diff --git a/fs/nfs/write.c b/fs/nfs/write.c
> index b753242..7316f7a 100644
> --- a/fs/nfs/write.c
> +++ b/fs/nfs/write.c
> @@ -439,6 +439,7 @@ nfs_mark_request_commit(struct nfs_page *req)
> req->wb_index,
> NFS_PAGE_TAG_COMMIT);
> spin_unlock(&inode->i_lock);
> + mem_cgroup_update_stat(req->wb_page, MEM_CGROUP_STAT_UNSTABLE_NFS, 1);
> inc_zone_page_state(req->wb_page, NR_UNSTABLE_NFS);
> inc_bdi_stat(req->wb_page->mapping->backing_dev_info, BDI_UNSTABLE);
> __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
> @@ -450,6 +451,7 @@ nfs_clear_request_commit(struct nfs_page *req)
> struct page *page = req->wb_page;
>
> if (test_and_clear_bit(PG_CLEAN, &(req)->wb_flags)) {
> + mem_cgroup_update_stat(page, MEM_CGROUP_STAT_UNSTABLE_NFS, -1);
> dec_zone_page_state(page, NR_UNSTABLE_NFS);
> dec_bdi_stat(page->mapping->backing_dev_info, BDI_UNSTABLE);
> return 1;
> @@ -1273,6 +1275,8 @@ nfs_commit_list(struct inode *inode, struct list_head *head, int how)
> req = nfs_list_entry(head->next);
> nfs_list_remove_request(req);
> nfs_mark_request_commit(req);
> + mem_cgroup_update_stat(req->wb_page,
> + MEM_CGROUP_STAT_UNSTABLE_NFS, -1);
> dec_zone_page_state(req->wb_page, NR_UNSTABLE_NFS);
> dec_bdi_stat(req->wb_page->mapping->backing_dev_info,
> BDI_UNSTABLE);
> diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c
> index ada2f1b..aef6d13 100644
> --- a/fs/nilfs2/segment.c
> +++ b/fs/nilfs2/segment.c
> @@ -1660,8 +1660,11 @@ nilfs_copy_replace_page_buffers(struct page *page, struct list_head *out)
> } while (bh = bh->b_this_page, bh2 = bh2->b_this_page, bh != head);
> kunmap_atomic(kaddr, KM_USER0);
>
> - if (!TestSetPageWriteback(clone_page))
> + if (!TestSetPageWriteback(clone_page)) {
> + mem_cgroup_update_stat(clone_page,
> + MEM_CGROUP_STAT_WRITEBACK, 1);
> inc_zone_page_state(clone_page, NR_WRITEBACK);
> + }
> unlock_page(clone_page);
>
> return 0;
> @@ -1783,8 +1786,11 @@ static void __nilfs_end_page_io(struct page *page, int err)
> }
>
> if (buffer_nilfs_allocated(page_buffers(page))) {
> - if (TestClearPageWriteback(page))
> + if (TestClearPageWriteback(page)) {
> + mem_cgroup_update_stat(clone_page,
> + MEM_CGROUP_STAT_WRITEBACK, -1);
> dec_zone_page_state(page, NR_WRITEBACK);
> + }
> } else
> end_page_writeback(page);
> }
> diff --git a/mm/filemap.c b/mm/filemap.c
> index fe09e51..f85acae 100644
> --- a/mm/filemap.c
> +++ b/mm/filemap.c
> @@ -135,6 +135,7 @@ void __remove_from_page_cache(struct page *page)
> * having removed the page entirely.
> */
> if (PageDirty(page) && mapping_cap_account_dirty(mapping)) {
> + mem_cgroup_update_stat(page, MEM_CGROUP_STAT_FILE_DIRTY, -1);
> dec_zone_page_state(page, NR_FILE_DIRTY);
> dec_bdi_stat(mapping->backing_dev_info, BDI_DIRTY);
> }
> diff --git a/mm/page-writeback.c b/mm/page-writeback.c
> index 5a0f8f3..d83f41c 100644
> --- a/mm/page-writeback.c
> +++ b/mm/page-writeback.c
> @@ -137,13 +137,14 @@ static struct prop_descriptor vm_dirties;
> */
> static int calc_period_shift(void)
> {
> - unsigned long dirty_total;
> + unsigned long dirty_total, dirty_bytes;
>
> - if (vm_dirty_bytes)
> - dirty_total = vm_dirty_bytes / PAGE_SIZE;
> + dirty_bytes = mem_cgroup_dirty_bytes();
> + if (dirty_bytes)
> + dirty_total = dirty_bytes / PAGE_SIZE;
> else
> - dirty_total = (vm_dirty_ratio * determine_dirtyable_memory()) /
> - 100;
> + dirty_total = (mem_cgroup_dirty_ratio() *
> + determine_dirtyable_memory()) / 100;
> return 2 + ilog2(dirty_total - 1);
> }
>
> @@ -408,14 +409,16 @@ static unsigned long highmem_dirtyable_memory(unsigned long total)
> */
> unsigned long determine_dirtyable_memory(void)
> {
> - unsigned long x;
> -
> - x = global_page_state(NR_FREE_PAGES) + global_reclaimable_pages();
> + unsigned long memory;
> + s64 memcg_memory;
>
> + memory = global_page_state(NR_FREE_PAGES) + global_reclaimable_pages();
> if (!vm_highmem_is_dirtyable)
> - x -= highmem_dirtyable_memory(x);
> -
> - return x + 1; /* Ensure that we never return 0 */
> + memory -= highmem_dirtyable_memory(memory);
> + memcg_memory = mem_cgroup_page_stat(MEMCG_NR_DIRTYABLE_PAGES);
> + if (memcg_memory < 0)
> + return memory + 1;
> + return min((unsigned long)memcg_memory, memory + 1);
> }
>
> void
> @@ -423,26 +426,28 @@ get_dirty_limits(unsigned long *pbackground, unsigned long *pdirty,
> unsigned long *pbdi_dirty, struct backing_dev_info *bdi)
> {
> unsigned long background;
> - unsigned long dirty;
> + unsigned long dirty, dirty_bytes, dirty_background;
> unsigned long available_memory = determine_dirtyable_memory();
> struct task_struct *tsk;
>
> - if (vm_dirty_bytes)
> - dirty = DIV_ROUND_UP(vm_dirty_bytes, PAGE_SIZE);
> + dirty_bytes = mem_cgroup_dirty_bytes();
> + if (dirty_bytes)
> + dirty = DIV_ROUND_UP(dirty_bytes, PAGE_SIZE);
> else {
> int dirty_ratio;
>
> - dirty_ratio = vm_dirty_ratio;
> + dirty_ratio = mem_cgroup_dirty_ratio();
> if (dirty_ratio < 5)
> dirty_ratio = 5;
> dirty = (dirty_ratio * available_memory) / 100;
> }
>
> - if (dirty_background_bytes)
> - background = DIV_ROUND_UP(dirty_background_bytes, PAGE_SIZE);
> + dirty_background = mem_cgroup_dirty_background_bytes();
> + if (dirty_background)
> + background = DIV_ROUND_UP(dirty_background, PAGE_SIZE);
> else
> - background = (dirty_background_ratio * available_memory) / 100;
> -
> + background = (mem_cgroup_dirty_background_ratio() *
> + available_memory) / 100;
> if (background >= dirty)
> background = dirty / 2;
> tsk = current;
> @@ -508,9 +513,13 @@ static void balance_dirty_pages(struct address_space *mapping,
> get_dirty_limits(&background_thresh, &dirty_thresh,
> &bdi_thresh, bdi);
>
> - nr_reclaimable = global_page_state(NR_FILE_DIRTY) +
> + nr_reclaimable = mem_cgroup_page_stat(MEMCG_NR_RECLAIM_PAGES);
> + nr_writeback = mem_cgroup_page_stat(MEMCG_NR_WRITEBACK);
> + if ((nr_reclaimable < 0) || (nr_writeback < 0)) {
> + nr_reclaimable = global_page_state(NR_FILE_DIRTY) +
> global_page_state(NR_UNSTABLE_NFS);
> - nr_writeback = global_page_state(NR_WRITEBACK);
> + nr_writeback = global_page_state(NR_WRITEBACK);
> + }
>
> bdi_nr_reclaimable = bdi_stat(bdi, BDI_DIRTY);
> if (bdi_cap_account_unstable(bdi)) {
> @@ -611,10 +620,12 @@ static void balance_dirty_pages(struct address_space *mapping,
> * In normal mode, we start background writeout at the lower
> * background_thresh, to keep the amount of dirty memory low.
> */
> + nr_reclaimable = mem_cgroup_page_stat(MEMCG_NR_RECLAIM_PAGES);
> + if (nr_reclaimable < 0)
> + nr_reclaimable = global_page_state(NR_FILE_DIRTY) +
> + global_page_state(NR_UNSTABLE_NFS);
> if ((laptop_mode && pages_written) ||
> - (!laptop_mode && ((global_page_state(NR_FILE_DIRTY)
> - + global_page_state(NR_UNSTABLE_NFS))
> - > background_thresh)))
> + (!laptop_mode && (nr_reclaimable > background_thresh)))
> bdi_start_writeback(bdi, NULL, 0);
> }
>
> @@ -678,6 +689,8 @@ void throttle_vm_writeout(gfp_t gfp_mask)
> unsigned long dirty_thresh;
>
> for ( ; ; ) {
> + unsigned long dirty;
> +
> get_dirty_limits(&background_thresh, &dirty_thresh, NULL, NULL);
>
> /*
> @@ -686,10 +699,14 @@ void throttle_vm_writeout(gfp_t gfp_mask)
> */
> dirty_thresh += dirty_thresh / 10; /* wheeee... */
>
> - if (global_page_state(NR_UNSTABLE_NFS) +
> - global_page_state(NR_WRITEBACK) <= dirty_thresh)
> - break;
> - congestion_wait(BLK_RW_ASYNC, HZ/10);
> +
> + dirty = mem_cgroup_page_stat(MEMCG_NR_DIRTY_WRITEBACK_PAGES);
> + if (dirty < 0)
> + dirty = global_page_state(NR_UNSTABLE_NFS) +
> + global_page_state(NR_WRITEBACK);

dirty is unsigned long. As mentioned last time, above will never be true?
In general these patches look ok to me. I will do some testing with these.

Vivek
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