The patch titled
Subject: mm: vmalloc: refactor vm_area_alloc_pages() function
has been added to the -mm mm-unstable branch. Its filename is
mm-vmalloc-refactor-vm_area_alloc_pages-function.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-vmalloc-refactor-vm_area_alloc_pages-function.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: "Uladzislau Rezki (Sony)" <urezki@xxxxxxxxx>
Subject: mm: vmalloc: refactor vm_area_alloc_pages() function
Date: Tue, 27 Aug 2024 21:09:16 +0200
The aim is to simplify and making the vm_area_alloc_pages()
function less confusing as it became more clogged nowadays:
- eliminate a "bulk_gfp" variable and do not overwrite a gfp
flag for bulk allocator;
- drop __GFP_NOFAIL flag for high-order-page requests on upper
layer. It becomes less spread between levels when it comes to
__GFP_NOFAIL allocations;
- add a comment about a fallback path if high-order attempt is
unsuccessful because for such cases __GFP_NOFAIL is dropped;
- fix a typo in a commit message.
Link: https://lkml.kernel.org/r/20240827190916.34242-1-urezki@xxxxxxxxx
Signed-off-by: Uladzislau Rezki (Sony) <urezki@xxxxxxxxx>
Cc: Baoquan He <bhe@xxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@xxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/vmalloc.c | 37 +++++++++++++++++--------------------
1 file changed, 17 insertions(+), 20 deletions(-)
--- a/mm/vmalloc.c~mm-vmalloc-refactor-vm_area_alloc_pages-function
+++ a/mm/vmalloc.c
@@ -3531,8 +3531,6 @@ vm_area_alloc_pages(gfp_t gfp, int nid,
unsigned int order, unsigned int nr_pages, struct page **pages)
{
unsigned int nr_allocated = 0;
- gfp_t alloc_gfp = gfp;
- bool nofail = gfp & __GFP_NOFAIL;
struct page *page;
int i;
@@ -3543,9 +3541,6 @@ vm_area_alloc_pages(gfp_t gfp, int nid,
* more permissive.
*/
if (!order) {
- /* bulk allocator doesn't support nofail req. officially */
- gfp_t bulk_gfp = gfp & ~__GFP_NOFAIL;
-
while (nr_allocated < nr_pages) {
unsigned int nr, nr_pages_request;
@@ -3563,12 +3558,11 @@ vm_area_alloc_pages(gfp_t gfp, int nid,
* but mempolicy wants to alloc memory by interleaving.
*/
if (IS_ENABLED(CONFIG_NUMA) && nid == NUMA_NO_NODE)
- nr = alloc_pages_bulk_array_mempolicy_noprof(bulk_gfp,
+ nr = alloc_pages_bulk_array_mempolicy_noprof(gfp,
nr_pages_request,
pages + nr_allocated);
-
else
- nr = alloc_pages_bulk_array_node_noprof(bulk_gfp, nid,
+ nr = alloc_pages_bulk_array_node_noprof(gfp, nid,
nr_pages_request,
pages + nr_allocated);
@@ -3582,30 +3576,24 @@ vm_area_alloc_pages(gfp_t gfp, int nid,
if (nr != nr_pages_request)
break;
}
- } else if (gfp & __GFP_NOFAIL) {
- /*
- * Higher order nofail allocations are really expensive and
- * potentially dangerous (pre-mature OOM, disruptive reclaim
- * and compaction etc.
- */
- alloc_gfp &= ~__GFP_NOFAIL;
}
/* High-order pages or fallback path if "bulk" fails. */
while (nr_allocated < nr_pages) {
- if (!nofail && fatal_signal_pending(current))
+ if (!(gfp & __GFP_NOFAIL) && fatal_signal_pending(current))
break;
if (nid == NUMA_NO_NODE)
- page = alloc_pages_noprof(alloc_gfp, order);
+ page = alloc_pages_noprof(gfp, order);
else
- page = alloc_pages_node_noprof(nid, alloc_gfp, order);
+ page = alloc_pages_node_noprof(nid, gfp, order);
+
if (unlikely(!page))
break;
/*
* Higher order allocations must be able to be treated as
- * indepdenent small pages by callers (as they can with
+ * independent small pages by callers (as they can with
* small-page vmallocs). Some drivers do their own refcounting
* on vmalloc_to_page() pages, some use page->mapping,
* page->lru, etc.
@@ -3666,7 +3654,16 @@ static void *__vmalloc_area_node(struct
set_vm_area_page_order(area, page_shift - PAGE_SHIFT);
page_order = vm_area_page_order(area);
- area->nr_pages = vm_area_alloc_pages(gfp_mask | __GFP_NOWARN,
+ /*
+ * Higher order nofail allocations are really expensive and
+ * potentially dangerous (pre-mature OOM, disruptive reclaim
+ * and compaction etc.
+ *
+ * Please note, the __vmalloc_node_range_noprof() falls-back
+ * to order-0 pages if high-order attempt is unsuccessful.
+ */
+ area->nr_pages = vm_area_alloc_pages((page_order ?
+ gfp_mask & ~__GFP_NOFAIL : gfp_mask) | __GFP_NOWARN,
node, page_order, nr_small_pages, area->pages);
atomic_long_add(area->nr_pages, &nr_vmalloc_pages);
_
Patches currently in -mm which might be from urezki@xxxxxxxxx are
mm-vmalloc-refactor-vm_area_alloc_pages-function.patch
