The branch main has been updated by olce:
URL:
https://cgit.FreeBSD.org/src/commit/?id=4ca9190251bbd00c928a3cba54712c3ec25e9e26
commit 4ca9190251bbd00c928a3cba54712c3ec25e9e26
Author: Olivier Certner <o...@freebsd.org>
AuthorDate: 2025-07-07 12:27:48 +0000
Commit: Olivier Certner <o...@freebsd.org>
CommitDate: 2025-07-13 06:41:19 +0000
LinuxKPI: alloc_pages(): Don't reclaim on __GFP_NORETRY
Pass VM_ALLOC_NORECLAIM to vm_page_alloc_noobj_contig() so that it
avoids reclaiming (currently, calling vm_reserv_reclaim_contig()).
According to Linux's documentation, __GFP_NORETRY should not cause any
"disruptive reclaim". alloc_pages() is called a lot from the amdgpu DRM
driver via ttm_pool_alloc(), which tries to allocate pages of the
highest order first and fallback to lower order pages (as allocating
contiguous physical pages is in fact not a requirement). This process
relies on failing fast, as requested by __GFP_NORETRY. See also related
commit 718d1928f874 ("LinuxKPI: make linux_alloc_pages() honor
__GFP_NORETRY").
Reviewed by: jeffpc_josefsipek.net, bz
MFC after: 10 days
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D51246
---
sys/compat/linuxkpi/common/src/linux_page.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/sys/compat/linuxkpi/common/src/linux_page.c
b/sys/compat/linuxkpi/common/src/linux_page.c
index ebb92eacbf9a..628af17df853 100644
--- a/sys/compat/linuxkpi/common/src/linux_page.c
+++ b/sys/compat/linuxkpi/common/src/linux_page.c
@@ -106,6 +106,7 @@ linux_alloc_pages(gfp_t flags, unsigned int order)
if ((flags & M_ZERO) != 0)
req |= VM_ALLOC_ZERO;
+
if (order == 0 && (flags & GFP_DMA32) == 0) {
page = vm_page_alloc_noobj(req);
if (page == NULL)
@@ -113,6 +114,10 @@ linux_alloc_pages(gfp_t flags, unsigned int order)
} else {
vm_paddr_t pmax = (flags & GFP_DMA32) ?
BUS_SPACE_MAXADDR_32BIT : BUS_SPACE_MAXADDR;
+
+ if ((flags & __GFP_NORETRY) != 0)
+ req |= VM_ALLOC_NORECLAIM;
+
retry:
page = vm_page_alloc_noobj_contig(req, npages, 0, pmax,
PAGE_SIZE, 0, VM_MEMATTR_DEFAULT);
