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 include/linux/swap.h.
Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
---
fs/inode.c | 3 +--
fs/xfs/xfs_buf.c | 3 +--
include/linux/swap.h | 17 ++++++++++++++++-
mm/slab.c | 3 +--
mm/slob.c | 6 ++----
mm/slub.c | 5 ++---
6 files changed, 23 insertions(+), 14 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..15d1e5a7c2d3 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;
+ mm_account_reclaimed_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..e131ac155fb9 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -153,13 +153,28 @@ 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
};
+/*
+ * 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.
+ */
+static inline void mm_account_reclaimed_pages(unsigned long pages)
+{
+ if (current->reclaim_state)
+ current->reclaim_state->reclaimed += 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);
}
--
2.40.0.577.gac1e443424-googOn Thu 13-04-23 10:40:34, Yosry Ahmed 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 include/linux/swap.h. > > Signed-off-by: Yosry Ahmed <yosryahmed@google.com> Acked-by: Michal Hocko <mhocko@suse.com> -- Michal Hocko SUSE Labs
On 13.04.23 12:40, Yosry Ahmed 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 Would "reclaimed_non_lru" be more expressive? Then, mm_account_reclaimed_pages() -> mm_account_non_lru_reclaimed_pages() Apart from that LGTM. -- Thanks, David / dhildenb
On Thu, Apr 13, 2023 at 4:21 AM David Hildenbrand <david@redhat.com> wrote: > > On 13.04.23 12:40, Yosry Ahmed 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 > > Would "reclaimed_non_lru" be more expressive? Then, > > mm_account_reclaimed_pages() -> mm_account_non_lru_reclaimed_pages() > > > Apart from that LGTM. Thanks! I suck at naming things. If you think "reclaimed_non_lru" is better, then we can do that. FWIW mm_account_reclaimed_pages() was taken from a suggestion from Dave Chinner. My initial version had a terrible name: report_freed_pages(), so I am happy with whatever you see fit. Should I re-spin for this or can we change it in place? > > -- > Thanks, > > David / dhildenb >
On Thu, Apr 13, 2023 at 04:29:43AM -0700, Yosry Ahmed wrote: > On Thu, Apr 13, 2023 at 4:21 AM David Hildenbrand <david@redhat.com> wrote: > > > > On 13.04.23 12:40, Yosry Ahmed 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 > > > > Would "reclaimed_non_lru" be more expressive? Then, > > > > mm_account_reclaimed_pages() -> mm_account_non_lru_reclaimed_pages() > > > > > > Apart from that LGTM. > > Thanks! > > I suck at naming things. If you think "reclaimed_non_lru" is better, > then we can do that. FWIW mm_account_reclaimed_pages() was taken from > a suggestion from Dave Chinner. My initial version had a terrible > name: report_freed_pages(), so I am happy with whatever you see fit. > > Should I re-spin for this or can we change it in place? I don't care for the noise all the bikeshed painting has generated for a simple change like this. If it's a fix for a bug, and the naming is good enough, just merge it already, ok? -Dave. -- Dave Chinner david@fromorbit.com
On Thu, Apr 13, 2023 at 2:01 PM Dave Chinner <david@fromorbit.com> wrote: > > On Thu, Apr 13, 2023 at 04:29:43AM -0700, Yosry Ahmed wrote: > > On Thu, Apr 13, 2023 at 4:21 AM David Hildenbrand <david@redhat.com> wrote: > > > > > > On 13.04.23 12:40, Yosry Ahmed 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 > > > > > > Would "reclaimed_non_lru" be more expressive? Then, > > > > > > mm_account_reclaimed_pages() -> mm_account_non_lru_reclaimed_pages() > > > > > > > > > Apart from that LGTM. > > > > Thanks! > > > > I suck at naming things. If you think "reclaimed_non_lru" is better, > > then we can do that. FWIW mm_account_reclaimed_pages() was taken from > > a suggestion from Dave Chinner. My initial version had a terrible > > name: report_freed_pages(), so I am happy with whatever you see fit. > > > > Should I re-spin for this or can we change it in place? > > I don't care for the noise all the bikeshed painting has generated > for a simple change like this. If it's a fix for a bug, and the > naming is good enough, just merge it already, ok? Sorry for all the noise. I think this version is in good enough shape. Andrew, could you please replace v4 with this v6 without patch 2 as multiple people pointed out that it is unneeded? Sorry for the hassle. > > -Dave. > -- > Dave Chinner > david@fromorbit.com
On Thu, 13 Apr 2023 14:38:03 -0700 Yosry Ahmed <yosryahmed@google.com> wrote: > > > I suck at naming things. If you think "reclaimed_non_lru" is better, > > > then we can do that. FWIW mm_account_reclaimed_pages() was taken from > > > a suggestion from Dave Chinner. My initial version had a terrible > > > name: report_freed_pages(), so I am happy with whatever you see fit. > > > > > > Should I re-spin for this or can we change it in place? > > > > I don't care for the noise all the bikeshed painting has generated > > for a simple change like this. If it's a fix for a bug, and the > > naming is good enough, just merge it already, ok? > > Sorry for all the noise. I think this version is in good enough shape. > > Andrew, could you please replace v4 with this v6 without patch 2 as > multiple people pointed out that it is unneeded? Sorry for the hassle. I like patch 2! mm.git presently has the v6 series. All of it ;)
On Fri, Apr 14, 2023 at 2:47 PM Andrew Morton <akpm@linux-foundation.org> wrote: > > On Thu, 13 Apr 2023 14:38:03 -0700 Yosry Ahmed <yosryahmed@google.com> wrote: > > > > > I suck at naming things. If you think "reclaimed_non_lru" is better, > > > > then we can do that. FWIW mm_account_reclaimed_pages() was taken from > > > > a suggestion from Dave Chinner. My initial version had a terrible > > > > name: report_freed_pages(), so I am happy with whatever you see fit. > > > > > > > > Should I re-spin for this or can we change it in place? > > > > > > I don't care for the noise all the bikeshed painting has generated > > > for a simple change like this. If it's a fix for a bug, and the > > > naming is good enough, just merge it already, ok? > > > > Sorry for all the noise. I think this version is in good enough shape. > > > > Andrew, could you please replace v4 with this v6 without patch 2 as > > multiple people pointed out that it is unneeded? Sorry for the hassle. > > I like patch 2! > > mm.git presently has the v6 series. All of it ;) Thanks Andrew :)
On 13.04.23 13:29, Yosry Ahmed wrote: > On Thu, Apr 13, 2023 at 4:21 AM David Hildenbrand <david@redhat.com> wrote: >> >> On 13.04.23 12:40, Yosry Ahmed 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 >> >> Would "reclaimed_non_lru" be more expressive? Then, >> >> mm_account_reclaimed_pages() -> mm_account_non_lru_reclaimed_pages() >> >> >> Apart from that LGTM. > > Thanks! > > I suck at naming things. If you think "reclaimed_non_lru" is better, > then we can do that. FWIW mm_account_reclaimed_pages() was taken from > a suggestion from Dave Chinner. My initial version had a terrible > name: report_freed_pages(), so I am happy with whatever you see fit. > > Should I re-spin for this or can we change it in place? Respin would be good, but maybe wait a bit more on other comments. I'm bad at naming things as well :) -- Thanks, David / dhildenb
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