diff mbox series

[v2,2/3] mm: vmscan: refactor updating reclaimed pages in reclaim_state

Message ID 20230309093109.3039327-3-yosryahmed@google.com (mailing list archive)
State New
Headers show
Series Ignore non-LRU-based reclaim in memcg reclaim | expand

Commit Message

Yosry Ahmed March 9, 2023, 9:31 a.m. UTC
During reclaim, we keep track of pages reclaimed from other means than
LRU-based reclaim through scan_control->reclaim_state->reclaimed_slab,
which we stash a pointer to in current task_struct.

However, we keep track of more than just reclaimed slab pages through
this. We also use it for clean file pages dropped through pruned inodes,
and xfs buffer pages freed. Rename reclaimed_slab to reclaimed, and add
a helper function that wraps updating it through current, so that future
changes to this logic are contained within mm/vmscan.c.

Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
---
 fs/inode.c           |  3 +--
 fs/xfs/xfs_buf.c     |  3 +--
 include/linux/swap.h |  5 ++++-
 mm/slab.c            |  3 +--
 mm/slob.c            |  6 ++----
 mm/slub.c            |  5 ++---
 mm/vmscan.c          | 36 ++++++++++++++++++++++++++++++------
 7 files changed, 41 insertions(+), 20 deletions(-)

Comments

Yosry Ahmed March 9, 2023, 9:39 a.m. UTC | #1
On Thu, Mar 9, 2023 at 1:31 AM Yosry Ahmed <yosryahmed@google.com> wrote:
>
> During reclaim, we keep track of pages reclaimed from other means than
> LRU-based reclaim through scan_control->reclaim_state->reclaimed_slab,
> which we stash a pointer to in current task_struct.
>
> However, we keep track of more than just reclaimed slab pages through
> this. We also use it for clean file pages dropped through pruned inodes,
> and xfs buffer pages freed. Rename reclaimed_slab to reclaimed, and add
> a helper function that wraps updating it through current, so that future
> changes to this logic are contained within mm/vmscan.c.
>
> Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
> ---
>  fs/inode.c           |  3 +--
>  fs/xfs/xfs_buf.c     |  3 +--
>  include/linux/swap.h |  5 ++++-
>  mm/slab.c            |  3 +--
>  mm/slob.c            |  6 ++----
>  mm/slub.c            |  5 ++---
>  mm/vmscan.c          | 36 ++++++++++++++++++++++++++++++------
>  7 files changed, 41 insertions(+), 20 deletions(-)
>
> diff --git a/fs/inode.c b/fs/inode.c
> index 4558dc2f1355..e60fcc41faf1 100644
> --- a/fs/inode.c
> +++ b/fs/inode.c
> @@ -864,8 +864,7 @@ static enum lru_status inode_lru_isolate(struct list_head *item,
>                                 __count_vm_events(KSWAPD_INODESTEAL, reap);
>                         else
>                                 __count_vm_events(PGINODESTEAL, reap);
> -                       if (current->reclaim_state)
> -                               current->reclaim_state->reclaimed_slab += reap;
> +                       mm_account_reclaimed_pages(reap);
>                 }
>                 iput(inode);
>                 spin_lock(lru_lock);
> diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
> index 54c774af6e1c..060079f1e966 100644
> --- a/fs/xfs/xfs_buf.c
> +++ b/fs/xfs/xfs_buf.c
> @@ -286,8 +286,7 @@ xfs_buf_free_pages(
>                 if (bp->b_pages[i])
>                         __free_page(bp->b_pages[i]);
>         }
> -       if (current->reclaim_state)
> -               current->reclaim_state->reclaimed_slab += bp->b_page_count;
> +       report_freed_pages(bp->b_page_count);


Ugh I missed updating this one to mm_account_reclaimed_page().

This fixup needs to be squashed here. I will include it in v3 if a
respin is needed, otherwise I hope Andrew can squash it in.

diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index 060079f1e966..15d1e5a7c2d3 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -286,7 +286,7 @@ xfs_buf_free_pages(
                if (bp->b_pages[i])
                        __free_page(bp->b_pages[i]);
        }
-       report_freed_pages(bp->b_page_count);
+       mm_account_reclaimed_pages(bp->b_page_count);

        if (bp->b_pages != bp->b_page_array)
                kmem_free(bp->b_pages);

>
>
>         if (bp->b_pages != bp->b_page_array)
>                 kmem_free(bp->b_pages);
> diff --git a/include/linux/swap.h b/include/linux/swap.h
> index 209a425739a9..589ea2731931 100644
> --- a/include/linux/swap.h
> +++ b/include/linux/swap.h
> @@ -153,13 +153,16 @@ union swap_header {
>   * memory reclaim
>   */
>  struct reclaim_state {
> -       unsigned long reclaimed_slab;
> +       /* pages reclaimed outside of LRU-based reclaim */
> +       unsigned long reclaimed;
>  #ifdef CONFIG_LRU_GEN
>         /* per-thread mm walk data */
>         struct lru_gen_mm_walk *mm_walk;
>  #endif
>  };
>
> +void mm_account_reclaimed_pages(unsigned long pages);
> +
>  #ifdef __KERNEL__
>
>  struct address_space;
> diff --git a/mm/slab.c b/mm/slab.c
> index dabc2a671fc6..64bf1de817b2 100644
> --- a/mm/slab.c
> +++ b/mm/slab.c
> @@ -1392,8 +1392,7 @@ static void kmem_freepages(struct kmem_cache *cachep, struct slab *slab)
>         smp_wmb();
>         __folio_clear_slab(folio);
>
> -       if (current->reclaim_state)
> -               current->reclaim_state->reclaimed_slab += 1 << order;
> +       mm_account_reclaimed_pages(1 << order);
>         unaccount_slab(slab, order, cachep);
>         __free_pages(&folio->page, order);
>  }
> diff --git a/mm/slob.c b/mm/slob.c
> index fe567fcfa3a3..79cc8680c973 100644
> --- a/mm/slob.c
> +++ b/mm/slob.c
> @@ -61,7 +61,7 @@
>  #include <linux/slab.h>
>
>  #include <linux/mm.h>
> -#include <linux/swap.h> /* struct reclaim_state */
> +#include <linux/swap.h> /* mm_account_reclaimed_pages() */
>  #include <linux/cache.h>
>  #include <linux/init.h>
>  #include <linux/export.h>
> @@ -211,9 +211,7 @@ static void slob_free_pages(void *b, int order)
>  {
>         struct page *sp = virt_to_page(b);
>
> -       if (current->reclaim_state)
> -               current->reclaim_state->reclaimed_slab += 1 << order;
> -
> +       mm_account_reclaimed_pages(1 << order);
>         mod_node_page_state(page_pgdat(sp), NR_SLAB_UNRECLAIMABLE_B,
>                             -(PAGE_SIZE << order));
>         __free_pages(sp, order);
> diff --git a/mm/slub.c b/mm/slub.c
> index 39327e98fce3..7aa30eef8235 100644
> --- a/mm/slub.c
> +++ b/mm/slub.c
> @@ -11,7 +11,7 @@
>   */
>
>  #include <linux/mm.h>
> -#include <linux/swap.h> /* struct reclaim_state */
> +#include <linux/swap.h> /* mm_account_reclaimed_pages() */
>  #include <linux/module.h>
>  #include <linux/bit_spinlock.h>
>  #include <linux/interrupt.h>
> @@ -2063,8 +2063,7 @@ static void __free_slab(struct kmem_cache *s, struct slab *slab)
>         /* Make the mapping reset visible before clearing the flag */
>         smp_wmb();
>         __folio_clear_slab(folio);
> -       if (current->reclaim_state)
> -               current->reclaim_state->reclaimed_slab += pages;
> +       mm_account_reclaimed_pages(pages);
>         unaccount_slab(slab, order, s);
>         __free_pages(&folio->page, order);
>  }
> diff --git a/mm/vmscan.c b/mm/vmscan.c
> index fef7d1c0f82b..a3e38851b34a 100644
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -511,6 +511,34 @@ static void set_task_reclaim_state(struct task_struct *task,
>         task->reclaim_state = rs;
>  }
>
> +/*
> + * mm_account_reclaimed_pages(): account reclaimed pages outside of LRU-based
> + * reclaim
> + * @pages: number of pages reclaimed
> + *
> + * If the current process is undergoing a reclaim operation, increment the
> + * number of reclaimed pages by @pages.
> + */
> +void mm_account_reclaimed_pages(unsigned long pages)
> +{
> +       if (current->reclaim_state)
> +               current->reclaim_state->reclaimed += pages;
> +}
> +EXPORT_SYMBOL(mm_account_reclaimed_pages);
> +
> +/*
> + * flush_reclaim_state(): add pages reclaimed outside of LRU-based reclaim to
> + * scan_control->nr_reclaimed.
> + */
> +static void flush_reclaim_state(struct scan_control *sc,
> +                               struct reclaim_state *rs)
> +{
> +       if (rs) {
> +               sc->nr_reclaimed += rs->reclaimed;
> +               rs->reclaimed = 0;
> +       }
> +}
> +
>  static long xchg_nr_deferred(struct shrinker *shrinker,
>                              struct shrink_control *sc)
>  {
> @@ -5346,8 +5374,7 @@ static int shrink_one(struct lruvec *lruvec, struct scan_control *sc)
>                 vmpressure(sc->gfp_mask, memcg, false, sc->nr_scanned - scanned,
>                            sc->nr_reclaimed - reclaimed);
>
> -       sc->nr_reclaimed += current->reclaim_state->reclaimed_slab;
> -       current->reclaim_state->reclaimed_slab = 0;
> +       flush_reclaim_state(sc, current->reclaim_state);
>
>         return success ? MEMCG_LRU_YOUNG : 0;
>  }
> @@ -6472,10 +6499,7 @@ static void shrink_node(pg_data_t *pgdat, struct scan_control *sc)
>
>         shrink_node_memcgs(pgdat, sc);
>
> -       if (reclaim_state) {
> -               sc->nr_reclaimed += reclaim_state->reclaimed_slab;
> -               reclaim_state->reclaimed_slab = 0;
> -       }
> +       flush_reclaim_state(sc, reclaim_state);
>
>         /* Record the subtree's reclaim efficiency */
>         if (!sc->proactive)
> --
> 2.40.0.rc0.216.gc4246ad0f0-goog
>
kernel test robot March 10, 2023, 2:37 a.m. UTC | #2
Hi Yosry,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on xfs-linux/for-next]
[also build test ERROR on linus/master v6.3-rc1 next-20230309]
[cannot apply to akpm-mm/mm-everything vbabka-slab/for-next]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Yosry-Ahmed/mm-vmscan-move-set_task_reclaim_state-after-cgroup_reclaim/20230309-173354
base:   https://git.kernel.org/pub/scm/fs/xfs/xfs-linux.git for-next
patch link:    https://lore.kernel.org/r/20230309093109.3039327-3-yosryahmed%40google.com
patch subject: [PATCH v2 2/3] mm: vmscan: refactor updating reclaimed pages in reclaim_state
config: powerpc-g5_defconfig (https://download.01.org/0day-ci/archive/20230310/202303101037.13QFIjZH-lkp@intel.com/config)
compiler: clang version 17.0.0 (https://github.com/llvm/llvm-project 67409911353323ca5edf2049ef0df54132fa1ca7)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install powerpc cross compiling tool for clang build
        # apt-get install binutils-powerpc-linux-gnu
        # https://github.com/intel-lab-lkp/linux/commit/63df60b27250f3f7a2892f99f27258b60a6e8e13
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Yosry-Ahmed/mm-vmscan-move-set_task_reclaim_state-after-cgroup_reclaim/20230309-173354
        git checkout 63df60b27250f3f7a2892f99f27258b60a6e8e13
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=powerpc olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=powerpc SHELL=/bin/bash arch/powerpc/kernel/ drivers/net/usb/ fs/xfs/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202303101037.13QFIjZH-lkp@intel.com/

All errors (new ones prefixed by >>):

>> fs/xfs/xfs_buf.c:289:2: error: call to undeclared function 'report_freed_pages'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
           report_freed_pages(bp->b_page_count);
           ^
   fs/xfs/xfs_buf.c:289:2: note: did you mean 'mempool_free_pages'?
   include/linux/mempool.h:102:6: note: 'mempool_free_pages' declared here
   void mempool_free_pages(void *element, void *pool_data);
        ^
   1 error generated.


vim +/report_freed_pages +289 fs/xfs/xfs_buf.c

   273	
   274	static void
   275	xfs_buf_free_pages(
   276		struct xfs_buf	*bp)
   277	{
   278		uint		i;
   279	
   280		ASSERT(bp->b_flags & _XBF_PAGES);
   281	
   282		if (xfs_buf_is_vmapped(bp))
   283			vm_unmap_ram(bp->b_addr, bp->b_page_count);
   284	
   285		for (i = 0; i < bp->b_page_count; i++) {
   286			if (bp->b_pages[i])
   287				__free_page(bp->b_pages[i]);
   288		}
 > 289		report_freed_pages(bp->b_page_count);
   290	
   291		if (bp->b_pages != bp->b_page_array)
   292			kmem_free(bp->b_pages);
   293		bp->b_pages = NULL;
   294		bp->b_flags &= ~_XBF_PAGES;
   295	}
   296
diff mbox series

Patch

diff --git a/fs/inode.c b/fs/inode.c
index 4558dc2f1355..e60fcc41faf1 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -864,8 +864,7 @@  static enum lru_status inode_lru_isolate(struct list_head *item,
 				__count_vm_events(KSWAPD_INODESTEAL, reap);
 			else
 				__count_vm_events(PGINODESTEAL, reap);
-			if (current->reclaim_state)
-				current->reclaim_state->reclaimed_slab += reap;
+			mm_account_reclaimed_pages(reap);
 		}
 		iput(inode);
 		spin_lock(lru_lock);
diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index 54c774af6e1c..060079f1e966 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -286,8 +286,7 @@  xfs_buf_free_pages(
 		if (bp->b_pages[i])
 			__free_page(bp->b_pages[i]);
 	}
-	if (current->reclaim_state)
-		current->reclaim_state->reclaimed_slab += bp->b_page_count;
+	report_freed_pages(bp->b_page_count);
 
 	if (bp->b_pages != bp->b_page_array)
 		kmem_free(bp->b_pages);
diff --git a/include/linux/swap.h b/include/linux/swap.h
index 209a425739a9..589ea2731931 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -153,13 +153,16 @@  union swap_header {
  * memory reclaim
  */
 struct reclaim_state {
-	unsigned long reclaimed_slab;
+	/* pages reclaimed outside of LRU-based reclaim */
+	unsigned long reclaimed;
 #ifdef CONFIG_LRU_GEN
 	/* per-thread mm walk data */
 	struct lru_gen_mm_walk *mm_walk;
 #endif
 };
 
+void mm_account_reclaimed_pages(unsigned long pages);
+
 #ifdef __KERNEL__
 
 struct address_space;
diff --git a/mm/slab.c b/mm/slab.c
index dabc2a671fc6..64bf1de817b2 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1392,8 +1392,7 @@  static void kmem_freepages(struct kmem_cache *cachep, struct slab *slab)
 	smp_wmb();
 	__folio_clear_slab(folio);
 
-	if (current->reclaim_state)
-		current->reclaim_state->reclaimed_slab += 1 << order;
+	mm_account_reclaimed_pages(1 << order);
 	unaccount_slab(slab, order, cachep);
 	__free_pages(&folio->page, order);
 }
diff --git a/mm/slob.c b/mm/slob.c
index fe567fcfa3a3..79cc8680c973 100644
--- a/mm/slob.c
+++ b/mm/slob.c
@@ -61,7 +61,7 @@ 
 #include <linux/slab.h>
 
 #include <linux/mm.h>
-#include <linux/swap.h> /* struct reclaim_state */
+#include <linux/swap.h> /* mm_account_reclaimed_pages() */
 #include <linux/cache.h>
 #include <linux/init.h>
 #include <linux/export.h>
@@ -211,9 +211,7 @@  static void slob_free_pages(void *b, int order)
 {
 	struct page *sp = virt_to_page(b);
 
-	if (current->reclaim_state)
-		current->reclaim_state->reclaimed_slab += 1 << order;
-
+	mm_account_reclaimed_pages(1 << order);
 	mod_node_page_state(page_pgdat(sp), NR_SLAB_UNRECLAIMABLE_B,
 			    -(PAGE_SIZE << order));
 	__free_pages(sp, order);
diff --git a/mm/slub.c b/mm/slub.c
index 39327e98fce3..7aa30eef8235 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -11,7 +11,7 @@ 
  */
 
 #include <linux/mm.h>
-#include <linux/swap.h> /* struct reclaim_state */
+#include <linux/swap.h> /* mm_account_reclaimed_pages() */
 #include <linux/module.h>
 #include <linux/bit_spinlock.h>
 #include <linux/interrupt.h>
@@ -2063,8 +2063,7 @@  static void __free_slab(struct kmem_cache *s, struct slab *slab)
 	/* Make the mapping reset visible before clearing the flag */
 	smp_wmb();
 	__folio_clear_slab(folio);
-	if (current->reclaim_state)
-		current->reclaim_state->reclaimed_slab += pages;
+	mm_account_reclaimed_pages(pages);
 	unaccount_slab(slab, order, s);
 	__free_pages(&folio->page, order);
 }
diff --git a/mm/vmscan.c b/mm/vmscan.c
index fef7d1c0f82b..a3e38851b34a 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -511,6 +511,34 @@  static void set_task_reclaim_state(struct task_struct *task,
 	task->reclaim_state = rs;
 }
 
+/*
+ * mm_account_reclaimed_pages(): account reclaimed pages outside of LRU-based
+ * reclaim
+ * @pages: number of pages reclaimed
+ *
+ * If the current process is undergoing a reclaim operation, increment the
+ * number of reclaimed pages by @pages.
+ */
+void mm_account_reclaimed_pages(unsigned long pages)
+{
+	if (current->reclaim_state)
+		current->reclaim_state->reclaimed += pages;
+}
+EXPORT_SYMBOL(mm_account_reclaimed_pages);
+
+/*
+ * flush_reclaim_state(): add pages reclaimed outside of LRU-based reclaim to
+ * scan_control->nr_reclaimed.
+ */
+static void flush_reclaim_state(struct scan_control *sc,
+				struct reclaim_state *rs)
+{
+	if (rs) {
+		sc->nr_reclaimed += rs->reclaimed;
+		rs->reclaimed = 0;
+	}
+}
+
 static long xchg_nr_deferred(struct shrinker *shrinker,
 			     struct shrink_control *sc)
 {
@@ -5346,8 +5374,7 @@  static int shrink_one(struct lruvec *lruvec, struct scan_control *sc)
 		vmpressure(sc->gfp_mask, memcg, false, sc->nr_scanned - scanned,
 			   sc->nr_reclaimed - reclaimed);
 
-	sc->nr_reclaimed += current->reclaim_state->reclaimed_slab;
-	current->reclaim_state->reclaimed_slab = 0;
+	flush_reclaim_state(sc, current->reclaim_state);
 
 	return success ? MEMCG_LRU_YOUNG : 0;
 }
@@ -6472,10 +6499,7 @@  static void shrink_node(pg_data_t *pgdat, struct scan_control *sc)
 
 	shrink_node_memcgs(pgdat, sc);
 
-	if (reclaim_state) {
-		sc->nr_reclaimed += reclaim_state->reclaimed_slab;
-		reclaim_state->reclaimed_slab = 0;
-	}
+	flush_reclaim_state(sc, reclaim_state);
 
 	/* Record the subtree's reclaim efficiency */
 	if (!sc->proactive)