The patch titled
Subject: mm: replace xa_get_order with xas_get_order where appropriate
has been added to the -mm mm-unstable branch. Its filename is
mm-replace-xa_get_order-with-xas_get_order-where-appropriate.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-replace-xa_get_order-with-xas_get_order-where-appropriate.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Shakeel Butt <shakeel.butt@xxxxxxxxx>
Subject: mm: replace xa_get_order with xas_get_order where appropriate
Date: Fri, 6 Sep 2024 16:05:12 -0700
The tracing of invalidation and truncation operations on large files
showed that xa_get_order() is among the top functions where kernel spends
a lot of CPUs. xa_get_order() needs to traverse the tree to reach the
right node for a given index and then extract the order of the entry.
However it seems like at many places it is being called within an already
happening tree traversal where there is no need to do another traversal.
Just use xas_get_order() at those places.
Link: https://lkml.kernel.org/r/20240906230512.124643-1-shakeel.butt@xxxxxxxxx
Signed-off-by: Shakeel Butt <shakeel.butt@xxxxxxxxx>
Cc: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Nhat Pham <nphamcs@xxxxxxxxx>
Cc: Liam Howlett <liam.howlett@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/filemap.c | 6 +++---
mm/shmem.c | 2 +-
2 files changed, 4 insertions(+), 4 deletions(-)
--- a/mm/filemap.c~mm-replace-xa_get_order-with-xas_get_order-where-appropriate
+++ a/mm/filemap.c
@@ -2112,7 +2112,7 @@ unsigned find_lock_entries(struct addres
VM_BUG_ON_FOLIO(!folio_contains(folio, xas.xa_index),
folio);
} else {
- nr = 1 << xa_get_order(&mapping->i_pages, xas.xa_index);
+ nr = 1 << xas_get_order(&xas);
base = xas.xa_index & ~(nr - 1);
/* Omit order>0 value which begins before the start */
if (base < *start)
@@ -3005,7 +3005,7 @@ unlock:
static inline size_t seek_folio_size(struct xa_state *xas, struct folio *folio)
{
if (xa_is_value(folio))
- return PAGE_SIZE << xa_get_order(xas->xa, xas->xa_index);
+ return PAGE_SIZE << xas_get_order(xas);
return folio_size(folio);
}
@@ -4301,7 +4301,7 @@ static void filemap_cachestat(struct add
if (xas_retry(&xas, folio))
continue;
- order = xa_get_order(xas.xa, xas.xa_index);
+ order = xas_get_order(&xas);
nr_pages = 1 << order;
folio_first_index = round_down(xas.xa_index, 1 << order);
folio_last_index = folio_first_index + nr_pages - 1;
--- a/mm/shmem.c~mm-replace-xa_get_order-with-xas_get_order-where-appropriate
+++ a/mm/shmem.c
@@ -890,7 +890,7 @@ unsigned long shmem_partial_swap_usage(s
if (xas_retry(&xas, page))
continue;
if (xa_is_value(page))
- swapped += 1 << xa_get_order(xas.xa, xas.xa_index);
+ swapped += 1 << xas_get_order(&xas);
if (xas.xa_index == max)
break;
if (need_resched()) {
_
Patches currently in -mm which might be from shakeel.butt@xxxxxxxxx are
mm-replace-xa_get_order-with-xas_get_order-where-appropriate.patch
