From: Dev Jain <dev.jain@arm.com>
To: akpm@linux-foundation.org
Cc: rppt@kernel.org, ryan.roberts@arm.com, linux-mm@kvack.org,
linux-kernel@vger.kernel.org, Dev Jain <dev.jain@arm.com>
Subject: [PATCH] mm: Remove PMD alignment constraint in execmem_vmalloc()
Date: Thu, 18 Sep 2025 15:04:53 +0530 [thread overview]
Message-ID: <20250918093453.75676-1-dev.jain@arm.com> (raw)
When using vmalloc with VM_ALLOW_HUGE_VMAP flag, it will set the alignment
to PMD_SIZE internally, if it deems huge mappings to be eligible.
Therefore, setting the alignment in execmem_vmalloc is redundant. Apart
from this, it also reduces the probability of allocation in case vmalloc
fails to allocate hugepages - in the fallback case, vmalloc tries to use
the original alignment and allocate basepages, which unfortunately will
again be PMD_SIZE passed over from execmem_vmalloc, thus constraining
the search for a free space in vmalloc region.
Therefore, remove this constraint.
Signed-off-by: Dev Jain <dev.jain@arm.com>
---
mm-selftests pass, but I am not sure if they touch execmem code, and I
have no experience with this code.
mm/execmem.c | 3 ---
1 file changed, 3 deletions(-)
diff --git a/mm/execmem.c b/mm/execmem.c
index 0822305413ec..810a4ba9c924 100644
--- a/mm/execmem.c
+++ b/mm/execmem.c
@@ -38,9 +38,6 @@ static void *execmem_vmalloc(struct execmem_range *range, size_t size,
if (kasan)
vm_flags |= VM_DEFER_KMEMLEAK;
- if (vm_flags & VM_ALLOW_HUGE_VMAP)
- align = PMD_SIZE;
-
p = __vmalloc_node_range(size, align, start, end, gfp_flags,
pgprot, vm_flags, NUMA_NO_NODE,
__builtin_return_address(0));
--
2.30.2
next reply other threads:[~2025-09-18 9:35 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-09-18 9:34 Dev Jain [this message]
2025-09-18 10:33 ` Mike Rapoport
2025-09-18 13:06 ` Ryan Roberts
2025-09-21 7:39 ` Mike Rapoport
2025-09-22 6:02 ` Anshuman Khandual
2025-09-22 6:50 ` Dev Jain
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20250918093453.75676-1-dev.jain@arm.com \
--to=dev.jain@arm.com \
--cc=akpm@linux-foundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=rppt@kernel.org \
--cc=ryan.roberts@arm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox