sys-fs/bees: Add memory fragmentation work-around

Signed-off-by: Kai Krakow <kai@kaishome.de>
Signed-off-by: Sam James <sam@gentoo.org>

2 files changed, 48 insertions, 0 deletions

diff --git a/sys-fs/bees/bees-9999.ebuild b/sys-fs/bees/bees-9999.ebuild
index 65c3cbecea85..1b164eb56b08 100644
--- a/sys-fs/bees/bees-9999.ebuild
+++ b/sys-fs/bees/bees-9999.ebuild
@@ -29,6 +29,10 @@ RDEPEND="${DEPEND}"
 CONFIG_CHECK="~BTRFS_FS"
 ERROR_BTRFS_FS="CONFIG_BTRFS_FS: bees does currently only work with btrfs"
 
+PATCHES=(
+	"${FILESDIR}/0001-HACK-crucible-Work-around-kernel-memory-fragmentatio.patch"
+)
+
 pkg_pretend() {
 	if [[ ${MERGE_TYPE} != buildonly ]]; then
 		if kernel_is -lt 4 11; then
@@ -66,6 +70,16 @@ pkg_pretend() {
 			ewarn "https://github.com/Zygo/bees/blob/master/docs/btrfs-kernel.md"
 			ewarn
 		fi
+		if kernel_is -gt 5 15 106; then
+			if kernel_is -lt 6 3 10; then
+				ewarn "With kernel versions 5.15.107 or later, there is a memory fragmentation"
+				ewarn "issue with LOGICAL_INO which can lead to cache thrashing and cause IO"
+				ewarn "latency spikes. This version ships with a work-around at the cost of not"
+				ewarn "handling highly duplicated filesystems that well. More details:"
+				ewarn "https://github.com/Zygo/bees/issues/260"
+				ewarn
+			fi
+		fi
 
 		elog "Bees recommends running the latest current kernel for performance and"
 		elog "reliability reasons, see README.md."
diff --git a/sys-fs/bees/files/0001-HACK-crucible-Work-around-kernel-memory-fragmentatio.patch b/sys-fs/bees/files/0001-HACK-crucible-Work-around-kernel-memory-fragmentatio.patch
new file mode 100644
index 000000000000..0ceb5cbfc79e
--- /dev/null
+++ b/sys-fs/bees/files/0001-HACK-crucible-Work-around-kernel-memory-fragmentatio.patch
@@ -0,0 +1,34 @@
+From 10c2006e627b5bda74f9f8aca1a574aa0e0e1eaa Mon Sep 17 00:00:00 2001
+From: Kai Krakow <kai@kaishome.de>
+Date: Sun, 9 Jul 2023 12:24:40 +0200
+Subject: [PATCH] HACK: crucible: Work around kernel memory fragmentation
+
+According to @Zygo:
+
+> This will drastically reduce the number of reflinks bees can handle
+> to a single extent, but that size is beyond more than enough for most
+> filesystems. Making the buffer smaller may also reduce the size of
+> vmallocs which might be aggravating the kernel's memory manager.
+
+Link: https://github.com/Zygo/bees/issues/260#issuecomment-1627586574
+Signed-off-by: Kai Krakow <kai@kaishome.de>
+---
+ include/crucible/fs.h | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/include/crucible/fs.h b/include/crucible/fs.h
+index 6d1780b..5da7da0 100644
+--- a/include/crucible/fs.h
++++ b/include/crucible/fs.h
+@@ -65,7 +65,7 @@ namespace crucible {
+ 	};
+ 
+ 	struct BtrfsIoctlLogicalInoArgs {
+-		BtrfsIoctlLogicalInoArgs(uint64_t logical, size_t buf_size = 16 * 1024 * 1024);
++		BtrfsIoctlLogicalInoArgs(uint64_t logical, size_t buf_size = 64 * 1024);
+ 
+ 		uint64_t get_flags() const;
+ 		void set_flags(uint64_t new_flags);
+-- 
+2.39.3
+