Re: [PATCH 2/2] memcg: dirty pages instrumentation
From: KAMEZAWA Hiroyuki
Date: Sun Feb 21 2010 - 19:36:08 EST
On Sun, 21 Feb 2010 16:18:45 +0100
Andrea Righi <arighi@xxxxxxxxxxx> wrote:
> Apply the cgroup dirty pages accounting and limiting infrastructure to
> the opportune kernel functions.
>
> Signed-off-by: Andrea Righi <arighi@xxxxxxxxxxx>
I think there are design confusion with 1st patch.
> ---
> fs/fuse/file.c | 3 ++
> fs/nfs/write.c | 3 ++
> fs/nilfs2/segment.c | 8 ++++-
> mm/filemap.c | 1 +
> mm/page-writeback.c | 69 ++++++++++++++++++++++++++++++++++++--------------
> mm/truncate.c | 1 +
> 6 files changed, 63 insertions(+), 22 deletions(-)
>
> diff --git a/fs/fuse/file.c b/fs/fuse/file.c
> index a9f5e13..357632a 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 +1130,7 @@ 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_charge_dirty(req->pages[0], NR_WRITEBACK_TEMP, -1);
Here, you account dirty pages to the memcg which page_cgroup belongs to.
Not to the root cgroup of hierarchical accouning.
> dec_zone_page_state(req->pages[0], NR_WRITEBACK_TEMP);
> bdi_writeout_inc(bdi);
> wake_up(&fi->page_waitq);
> @@ -1240,6 +1242,7 @@ static int fuse_writepage_locked(struct page *page)
> req->inode = inode;
>
> inc_bdi_stat(mapping->backing_dev_info, BDI_WRITEBACK);
> + mem_cgroup_charge_dirty(tmp_page, NR_WRITEBACK_TEMP, 1);
here too....
> 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 d63d964..3d9de01 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_charge_dirty(req->wb_page, NR_UNSTABLE_NFS, 1);
> inc_zone_page_state(req->wb_page, NR_UNSTABLE_NFS);
> inc_bdi_stat(req->wb_page->mapping->backing_dev_info, BDI_RECLAIMABLE);
> __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_charge_dirty(page, NR_UNSTABLE_NFS, -1);
> dec_zone_page_state(page, NR_UNSTABLE_NFS);
> dec_bdi_stat(page->mapping->backing_dev_info, BDI_RECLAIMABLE);
> return 1;
> @@ -1320,6 +1322,7 @@ 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_charge_dirty(req->wb_page, NR_UNSTABLE_NFS, -1);
> dec_zone_page_state(req->wb_page, NR_UNSTABLE_NFS);
> dec_bdi_stat(req->wb_page->mapping->backing_dev_info,
> BDI_RECLAIMABLE);
> diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c
> index 105b508..b9ffac5 100644
> --- a/fs/nilfs2/segment.c
> +++ b/fs/nilfs2/segment.c
> @@ -1660,8 +1660,10 @@ 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_charge_dirty(clone_page, NR_WRITEBACK, 1);
> inc_zone_page_state(clone_page, NR_WRITEBACK);
> + }
> unlock_page(clone_page);
>
> return 0;
> @@ -1788,8 +1790,10 @@ 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_charge_dirty(clone_page, NR_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 698ea80..c19d809 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_charge_dirty(page, NR_FILE_DIRTY, -1);
> dec_zone_page_state(page, NR_FILE_DIRTY);
> dec_bdi_stat(mapping->backing_dev_info, BDI_RECLAIMABLE);
> }
> diff --git a/mm/page-writeback.c b/mm/page-writeback.c
> index 0b19943..c9ff1cd 100644
> --- a/mm/page-writeback.c
> +++ b/mm/page-writeback.c
> @@ -137,10 +137,11 @@ 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();
Here, you get dirty pages of a memcg which the task belongs to.
Not from root memcg of the memcg-hierarchy which task belogns to.
> + if (dirty_bytes)
> + dirty_total = dirty_bytes / PAGE_SIZE;
> else
> dirty_total = (vm_dirty_ratio * determine_dirtyable_memory()) /
> 100;
> @@ -406,14 +407,20 @@ 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 memcg_memory, memory;
> +
> + memory = global_page_state(NR_FREE_PAGES) + global_reclaimable_pages();
> + memcg_memory = mem_cgroup_page_state(MEMCG_NR_FREE_PAGES);
> + if (memcg_memory > 0) {
> + memcg_memory +=
> + mem_cgroup_page_state(MEMCG_NR_RECLAIMABLE_PAGES);
> + if (memcg_memory < memory)
> + return memcg_memory;
> + }
Here, you get local usage.
> if (!vm_highmem_is_dirtyable)
> - x -= highmem_dirtyable_memory(x);
> + memory -= highmem_dirtyable_memory(memory);
>
> - return x + 1; /* Ensure that we never return 0 */
> + return memory + 1; /* Ensure that we never return 0 */
> }
>
> void
> @@ -421,12 +428,13 @@ 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;
> 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;
you use local value. But, if hierarchila accounting used, memcg->dirty_bytes
should be got from root-of-hierarchy memcg.
I have no objection if you add a pointer as
memcg->subhierarchy_root
to get root of hierarchical accounting. But please check problem of hierarchy, again.
Thanks,
-Kame
>
> @@ -505,9 +513,17 @@ 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_state(MEMCG_NR_FILE_DIRTY);
> + if (nr_reclaimable == 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);
> + } else {
> + nr_reclaimable +=
> + mem_cgroup_page_state(MEMCG_NR_UNSTABLE_NFS);
> + nr_writeback =
> + mem_cgroup_page_state(MEMCG_NR_WRITEBACK);
> + }
>
> bdi_nr_reclaimable = bdi_stat(bdi, BDI_RECLAIMABLE);
> bdi_nr_writeback = bdi_stat(bdi, BDI_WRITEBACK);
> @@ -660,6 +676,8 @@ 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);
>
> /*
> @@ -668,10 +686,15 @@ 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_state(MEMCG_NR_WRITEBACK);
> + if (dirty < 0)
> + dirty = global_page_state(NR_UNSTABLE_NFS) +
> + global_page_state(NR_WRITEBACK);
> + else
> + dirty += mem_cgroup_page_state(MEMCG_NR_UNSTABLE_NFS);
> + if (dirty <= dirty_thresh)
> + break;
> + congestion_wait(BLK_RW_ASYNC, HZ/10);
>
> /*
> * The caller might hold locks which can prevent IO completion
> @@ -1078,6 +1101,7 @@ int __set_page_dirty_no_writeback(struct page *page)
> void account_page_dirtied(struct page *page, struct address_space *mapping)
> {
> if (mapping_cap_account_dirty(mapping)) {
> + mem_cgroup_charge_dirty(page, NR_FILE_DIRTY, 1);
> __inc_zone_page_state(page, NR_FILE_DIRTY);
> __inc_bdi_stat(mapping->backing_dev_info, BDI_RECLAIMABLE);
> task_dirty_inc(current);
> @@ -1253,6 +1277,7 @@ int clear_page_dirty_for_io(struct page *page)
> * for more comments.
> */
> if (TestClearPageDirty(page)) {
> + mem_cgroup_charge_dirty(page, NR_FILE_DIRTY, -1);
> dec_zone_page_state(page, NR_FILE_DIRTY);
> dec_bdi_stat(mapping->backing_dev_info,
> BDI_RECLAIMABLE);
> @@ -1288,8 +1313,10 @@ int test_clear_page_writeback(struct page *page)
> } else {
> ret = TestClearPageWriteback(page);
> }
> - if (ret)
> + if (ret) {
> + mem_cgroup_charge_dirty(page, NR_WRITEBACK, -1);
> dec_zone_page_state(page, NR_WRITEBACK);
> + }
> return ret;
> }
>
> @@ -1319,8 +1346,10 @@ int test_set_page_writeback(struct page *page)
> } else {
> ret = TestSetPageWriteback(page);
> }
> - if (!ret)
> + if (!ret) {
> + mem_cgroup_charge_dirty(page, NR_WRITEBACK, 1);
> inc_zone_page_state(page, NR_WRITEBACK);
> + }
> return ret;
>
> }
> diff --git a/mm/truncate.c b/mm/truncate.c
> index e87e372..f44e370 100644
> --- a/mm/truncate.c
> +++ b/mm/truncate.c
> @@ -73,6 +73,7 @@ void cancel_dirty_page(struct page *page, unsigned int account_size)
> if (TestClearPageDirty(page)) {
> struct address_space *mapping = page->mapping;
> if (mapping && mapping_cap_account_dirty(mapping)) {
> + mem_cgroup_charge_dirty(page, NR_FILE_DIRTY, -1);
> dec_zone_page_state(page, NR_FILE_DIRTY);
> dec_bdi_stat(mapping->backing_dev_info,
> BDI_RECLAIMABLE);
> --
> 1.6.3.3
>
>
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