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);
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-googHi 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
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests
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
>
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