Re: PATCH v4 0/6] mm, drm/ttm, drm/xe: Avoid reclaim/eviction loops under fragmentation

[Kenneth Crudup <kenny@panix.com>]

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Perhaps this issue actually lies elsewhere?

I've been working with this patchset for a few days now and while it 
does seem to fix my "runaway kswapd" issue, every now and then I'd get a 
hard panic while seeking in large-format video files (using the "mpv" 
video player, FWIW). Suspecting it had to do with the shrinker path in 
this patch, I'd started looking at ways to burn thru memory to verify 
that hypothesis and found the following one-liner:

echo {1..1000000000}

It works perfectly- eats thru all it can, until it gets OOMed. Thing 
was, after this would run, kswapd would go runaway again, even if this 
was run on a freshly-booted system (I'd also have a few Chrome tabs open).

As I run Linus' master on my LunarLake box I tried running this again on 
the stock ((K)ubuntu 7.0.0-15-generic) kernel, and once the oom_reaper 
killed off the bash, the system settled down to normal again with no 
runaway kswapd as before. So I recompiled back to 7.0 with my preferred 
config options (minimal modules, a bigger log_buf, that kind of thing) 
and the runaway kswapd issue persisted after the bash was OOMed.

I then built 7.0.0 again, using the basic kernel.org source version (as 
I know sometimes Ubuntu special-sauces their kernels) BUT using the 
config from Ubuntu's stock generic 7.0, and huh- the problem didn't 
occur. I went all the way to 7.0.3 with the same result, so the problem 
had to have been in the config options I'd used.

It took some doing and some trial-and-error but I was able to generate a 
custom defconfig for my machine that has the right config options so 
that now after the bash gets killed off, kswapd quiets down. I've 
attached a diff of the savedefconfig'ed defconfig for reference (So is 
it CMA? PSI? CGROUP? ?? ... maybe someone here can tell me which option 
made the difference, I'm kind of over fine-graining it any longer :) )

But now here's the thing- since fixing the defconfig options, I'm now 
back to running Linus' master kernel (which has the drm-next Xe memory 
changes/fixes that presumably warrant the patchset in this thread) and 
no matter what I do to reproduce the reclaim/eviction loops (and I could 
easily before in the 7.1-rcX series- making a kernel, running bonnie++ , 
the bash one-liner above), I haven't been able to, and WITHOUT this patch.

-Kenny

On 5/1/26 12:08, Kenneth Crudup wrote:
> 
> On 4/30/26 12:18, Matthew Brost wrote:
> 
>> Introduce zone_maybe_fragmented_in_shrinker() as a lightweight helper to
>> allow subsystems to make coarse decisions about reclaim behavior in the
>> presence of likely fragmentation
> 
> I'm running Linus' master on my LunarLake (258v) laptop, and sometimes 
> after compiling a kernel (of all things) I'd see kswapd0 thrash despite 
> having quite a bit of free memory.
> 
> I finally traced it to the xe driver after seeing the "GPUActive" field 
> in /proc/meminfo suddenly start rising, eventually growing larger than 
> real memory by several times (see below).
> 
> This patchset fixes the issue, and I'm sure there'll be a fix going into 
> Linus' master soon, but what I'M wondering is how could building a 
> kernel (which is just in a KDE Konsole running on Wayland) make the 
> GPActive grow from ~1.6G to > 30G (and continue to rise, RN I'm seeing 
> 91839848 kBs and still growing).
> 
> -Kenny


-- 
Kenneth R. Crudup / Sr. SW Engineer, Scott County Consulting, Orange 
County CA

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From 8da53fa9d1741a3fcfd9a54fae9ca5cdcb5c0d0c Mon Sep 17 00:00:00 2001
From: "Kenneth R. Crudup" <kenny@panix.com>
Date: Thu, 7 May 2026 03:08:29 -0700
Subject: [PATCH] x86: Yoga9i: Fix memory-pressure issues, refine defconfig
 further

---
 arch/x86/configs/yoga9i_defconfig | 91 +++++++++++++------------------
 1 file changed, 38 insertions(+), 53 deletions(-)

diff --git a/arch/x86/configs/yoga9i_defconfig b/arch/x86/configs/yoga9i_defconfig
index d0afb050bdfb..d6dc42e89a9b 100644
--- a/arch/x86/configs/yoga9i_defconfig
+++ b/arch/x86/configs/yoga9i_defconfig
@@ -1,13 +1,15 @@
 CONFIG_LOCALVERSION="-kenny"
 # CONFIG_LOCALVERSION_AUTO is not set
 CONFIG_KERNEL_ZSTD=y
-CONFIG_DEFAULT_HOSTNAME="xps-9320"
+CONFIG_DEFAULT_HOSTNAME="yoga-9i"
 CONFIG_SYSVIPC=y
 CONFIG_POSIX_MQUEUE=y
 CONFIG_WATCH_QUEUE=y
 CONFIG_AUDIT=y
+CONFIG_NO_HZ_FULL=y
 CONFIG_NO_HZ=y
 CONFIG_HIGH_RES_TIMERS=y
+CONFIG_POSIX_AUX_CLOCKS=y
 CONFIG_BPF_SYSCALL=y
 CONFIG_BPF_JIT=y
 CONFIG_BPF_JIT_ALWAYS_ON=y
@@ -20,6 +22,7 @@ CONFIG_TASKSTATS=y
 CONFIG_TASK_DELAY_ACCT=y
 CONFIG_TASK_XACCT=y
 CONFIG_TASK_IO_ACCOUNTING=y
+CONFIG_PSI=y
 CONFIG_IKCONFIG=y
 CONFIG_IKCONFIG_PROC=y
 CONFIG_IKHEADERS=y
@@ -31,6 +34,7 @@ CONFIG_CFS_BANDWIDTH=y
 CONFIG_UCLAMP_TASK_GROUP=y
 CONFIG_CGROUP_PIDS=y
 CONFIG_CGROUP_RDMA=y
+CONFIG_CGROUP_DMEM=y
 CONFIG_CGROUP_FREEZER=y
 CONFIG_CGROUP_HUGETLB=y
 CONFIG_CPUSETS=y
@@ -75,12 +79,12 @@ CONFIG_EFI=y
 CONFIG_EFI_STUB=y
 CONFIG_EFI_MIXED=y
 CONFIG_HZ_1000=y
-CONFIG_RANDOMIZE_MEMORY_PHYSICAL_PADDING=0xa
 # CONFIG_CPU_MITIGATIONS is not set
 CONFIG_HIBERNATION=y
 # CONFIG_HIBERNATION_SNAPSHOT_DEV is not set
 CONFIG_PM_STD_PARTITION="/swapfile"
 CONFIG_PM_WAKELOCKS=y
+CONFIG_PM_QOS_CPU_SYSTEM_WAKEUP=y
 CONFIG_PM_DEBUG=y
 CONFIG_PM_ADVANCED_DEBUG=y
 CONFIG_PM_TRACE_RTC=y
@@ -144,21 +148,29 @@ CONFIG_ZSWAP_DEFAULT_ON=y
 CONFIG_ZSWAP_SHRINKER_DEFAULT_ON=y
 CONFIG_ZSWAP_COMPRESSOR_DEFAULT_LZ4=y
 CONFIG_SLAB_FREELIST_RANDOM=y
-CONFIG_SLAB_FREELIST_HARDENED=y
+CONFIG_SLAB_BUCKETS=y
+CONFIG_RANDOM_KMALLOC_CACHES=y
 CONFIG_SHUFFLE_PAGE_ALLOCATOR=y
 # CONFIG_COMPAT_BRK is not set
+CONFIG_MEMORY_HOTPLUG=y
+CONFIG_MHP_DEFAULT_ONLINE_TYPE_ONLINE_AUTO=y
+CONFIG_MEMORY_HOTREMOVE=y
 CONFIG_PAGE_REPORTING=y
 CONFIG_KSM=y
 CONFIG_DEFAULT_MMAP_MIN_ADDR=65536
 CONFIG_MEMORY_FAILURE=y
-CONFIG_PERSISTENT_HUGE_ZERO_FOLIO=y
 CONFIG_TRANSPARENT_HUGEPAGE=y
 CONFIG_TRANSPARENT_HUGEPAGE_MADVISE=y
-CONFIG_TRANSPARENT_HUGEPAGE_SHMEM_HUGE_ADVISE=y
-CONFIG_TRANSPARENT_HUGEPAGE_TMPFS_HUGE_ADVISE=y
+CONFIG_CMA=y
+CONFIG_CMA_DEBUGFS=y
+CONFIG_CMA_SYSFS=y
 CONFIG_MEM_SOFT_DIRTY=y
 CONFIG_IDLE_PAGE_TRACKING=y
+CONFIG_ZONE_DEVICE=y
+CONFIG_ANON_VMA_NAME=y
 CONFIG_USERFAULTFD=y
+CONFIG_LRU_GEN=y
+CONFIG_LRU_GEN_ENABLED=y
 CONFIG_NET=y
 CONFIG_PACKET=y
 CONFIG_PACKET_DIAG=y
@@ -387,10 +399,6 @@ CONFIG_BT_HIDP=y
 CONFIG_BT_LEDS=y
 CONFIG_BT_MSFTEXT=y
 CONFIG_BT_AOSPEXT=y
-CONFIG_BT_HCIBTUSB=m
-CONFIG_BT_HCIBTUSB_AUTOSUSPEND=y
-# CONFIG_BT_HCIBTUSB_BCM is not set
-# CONFIG_BT_HCIBTUSB_RTL is not set
 CONFIG_BT_INTEL_PCIE=m
 CONFIG_CFG80211=m
 CONFIG_CFG80211_DEBUGFS=y
@@ -400,6 +408,7 @@ CONFIG_MAC80211_MESH=y
 CONFIG_MAC80211_DEBUGFS=y
 CONFIG_RFKILL=y
 CONFIG_RFKILL_INPUT=y
+CONFIG_PAGE_POOL_STATS=y
 CONFIG_PCI=y
 CONFIG_PCIEAER=y
 CONFIG_PCIE_DPC=y
@@ -416,10 +425,12 @@ CONFIG_DEVTMPFS_MOUNT=y
 # CONFIG_STANDALONE is not set
 CONFIG_FW_LOADER_USER_HELPER=y
 CONFIG_FW_LOADER_COMPRESS=y
+CONFIG_FW_LOADER_COMPRESS_ZSTD=y
 CONFIG_CONNECTOR=y
 CONFIG_EDD=y
 CONFIG_EDD_OFF=y
 CONFIG_DMI_SYSFS=y
+CONFIG_SYSFB_SIMPLEFB=y
 CONFIG_EFI_BOOTLOADER_CONTROL=y
 CONFIG_RESET_ATTACK_MITIGATION=y
 CONFIG_EFI_RCI2_TABLE=y
@@ -438,8 +449,9 @@ CONFIG_SRAM=y
 CONFIG_EEPROM_AT24=y
 CONFIG_EEPROM_EE1004=y
 CONFIG_INTEL_MEI_GSC=y
+CONFIG_INTEL_MEI_CSC=y
 CONFIG_INTEL_MEI_GSC_PROXY=y
-CONFIG_VMWARE_VMCI=m
+CONFIG_VMWARE_VMCI=y
 CONFIG_SCSI=y
 CONFIG_BLK_DEV_SD=y
 CONFIG_CHR_DEV_ST=y
@@ -537,6 +549,7 @@ CONFIG_IGC=y
 # CONFIG_NET_VENDOR_XILINX is not set
 CONFIG_PHYLIB=y
 CONFIG_LED_TRIGGER_PHY=y
+CONFIG_FIXED_PHY=y
 CONFIG_AX88796B_PHY=y
 CONFIG_SMSC_PHY=y
 CONFIG_PPP=y
@@ -550,15 +563,15 @@ CONFIG_PPPOL2TP=y
 CONFIG_PPP_ASYNC=y
 CONFIG_USB_RTL8150=m
 CONFIG_USB_RTL8152=m
-CONFIG_USB_USBNET=m
+CONFIG_USB_USBNET=y
 # CONFIG_USB_NET_AX8817X is not set
-CONFIG_USB_NET_CDC_EEM=m
-CONFIG_USB_NET_CDC_MBIM=m
+CONFIG_USB_NET_AX88179_178A=m
+CONFIG_USB_NET_CDC_EEM=y
+CONFIG_USB_NET_CDC_MBIM=y
 # CONFIG_USB_NET_NET1080 is not set
 # CONFIG_USB_NET_CDC_SUBSET is not set
 # CONFIG_USB_NET_ZAURUS is not set
 CONFIG_USB_HSO=y
-CONFIG_USB_SIERRA_NET=m
 CONFIG_USB_NET_AQC111=m
 # CONFIG_WLAN_VENDOR_ADMTEK is not set
 # CONFIG_WLAN_VENDOR_ATH is not set
@@ -633,10 +646,10 @@ CONFIG_I2C_DESIGNWARE_PCI=y
 CONFIG_SPI=y
 CONFIG_SPI_MEM=y
 CONFIG_SPI_CH341=y
-CONFIG_SPI_CS42L43=m
+CONFIG_SPI_CS42L43=y
 CONFIG_SPI_INTEL_PCI=y
 # CONFIG_PTP_1588_CLOCK is not set
-CONFIG_PINCTRL_CS42L43=m
+CONFIG_PINCTRL_CS42L43=y
 CONFIG_PINCTRL_INTEL_PLATFORM=y
 CONFIG_PINCTRL_TIGERLAKE=y
 CONFIG_GPIO_SYSFS=y
@@ -670,7 +683,6 @@ CONFIG_WATCHDOG_SYSFS=y
 CONFIG_WDAT_WDT=y
 CONFIG_INTEL_OC_WATCHDOG=y
 CONFIG_ITCO_WDT=y
-CONFIG_MFD_CS42L43_SDW=y
 CONFIG_LPC_ICH=y
 CONFIG_LPC_SCH=y
 CONFIG_MFD_INTEL_LPSS_ACPI=y
@@ -687,8 +699,6 @@ CONFIG_MEDIA_USB_SUPPORT=y
 CONFIG_USB_GSPCA=y
 CONFIG_USB_VIDEO_CLASS=y
 CONFIG_MEDIA_PCI_SUPPORT=y
-CONFIG_VIDEO_INTEL_IPU6=m
-CONFIG_IPU_BRIDGE=y
 CONFIG_V4L_PLATFORM_DRIVERS=y
 CONFIG_V4L_MEM2MEM_DRIVERS=y
 CONFIG_VIDEO_MEM2MEM_DEINTERLACE=y
@@ -697,7 +707,7 @@ CONFIG_VIDEO_OV01A10=y
 CONFIG_DRM=y
 CONFIG_DRM_CLIENT_LOG=y
 CONFIG_DRM_DISPLAY_DP_AUX_CEC=y
-CONFIG_DRM_EFIDRM=y
+CONFIG_DRM_SIMPLEDRM=y
 CONFIG_DRM_UDL=y
 CONFIG_DRM_XE=m
 CONFIG_FB=y
@@ -741,7 +751,7 @@ CONFIG_SND_SOC=y
 # CONFIG_SND_SOC_INTEL_SST_TOPLEVEL is not set
 CONFIG_SND_SOC_INTEL_USER_FRIENDLY_LONG_NAMES=y
 CONFIG_SND_SOC_INTEL_SKL_HDA_DSP_GENERIC_MACH=y
-CONFIG_SND_SOC_INTEL_SOUNDWIRE_SOF_MACH=m
+CONFIG_SND_SOC_INTEL_SOUNDWIRE_SOF_MACH=y
 CONFIG_SND_SOC_SOF_TOPLEVEL=y
 CONFIG_SND_SOC_SOF_PCI=y
 CONFIG_SND_SOC_SOF_ACPI=y
@@ -760,23 +770,11 @@ CONFIG_SND_SOC_SOF_INTEL_TOPLEVEL=y
 # CONFIG_SND_SOC_SOF_ELKHARTLAKE is not set
 # CONFIG_SND_SOC_SOF_ALDERLAKE is not set
 # CONFIG_SND_SOC_SOF_METEORLAKE is not set
-CONFIG_SND_SOC_SOF_LUNARLAKE=m
+# CONFIG_SND_SOC_SOF_LUNARLAKE is not set
 # CONFIG_SND_SOC_SOF_PANTHERLAKE is not set
 CONFIG_SND_SOC_SOF_HDA_LINK=y
 CONFIG_SND_SOC_SOF_HDA_AUDIO_CODEC=y
-CONFIG_SND_SOC_CS35L56_I2C=m
 CONFIG_SND_SOC_HDA=y
-CONFIG_SND_SOC_MAX98363=y
-CONFIG_SND_SOC_MAX98373_I2C=y
-CONFIG_SND_SOC_MAX98373_SDW=y
-CONFIG_SND_SOC_RT1308_SDW=y
-CONFIG_SND_SOC_RT1316_SDW=y
-CONFIG_SND_SOC_RT5682_SDW=y
-CONFIG_SND_SOC_RT700_SDW=y
-CONFIG_SND_SOC_RT711_SDW=y
-CONFIG_SND_SOC_RT711_SDCA_SDW=y
-CONFIG_SND_SOC_RT715_SDW=y
-CONFIG_SND_SOC_RT715_SDCA_SDW=y
 # CONFIG_SND_SOC_SDW_MOCKUP is not set
 # CONFIG_SND_X86 is not set
 CONFIG_HID_BATTERY_STRENGTH=y
@@ -800,12 +798,9 @@ CONFIG_USB_LED_TRIG=y
 CONFIG_USB=y
 CONFIG_USB_ANNOUNCE_NEW_DEVICES=y
 CONFIG_USB_DYNAMIC_MINORS=y
-CONFIG_USB_LEDS_TRIGGER_USBPORT=y
-CONFIG_USB_MON=m
 CONFIG_USB_XHCI_HCD=y
 CONFIG_USB_ACM=y
 CONFIG_USB_PRINTER=y
-CONFIG_USB_WDM=y
 CONFIG_USB_STORAGE=y
 CONFIG_USB_UAS=y
 CONFIG_USB_SERIAL=y
@@ -815,13 +810,12 @@ CONFIG_USB_SERIAL_SIMPLE=y
 CONFIG_USB_SERIAL_BELKIN=y
 CONFIG_USB_SERIAL_CH341=y
 CONFIG_USB_SERIAL_CP210X=y
-CONFIG_USB_SERIAL_FTDI_SIO=m
+CONFIG_USB_SERIAL_FTDI_SIO=y
 CONFIG_USB_SERIAL_KEYSPAN_PDA=y
 CONFIG_USB_SERIAL_KEYSPAN=y
 CONFIG_USB_SERIAL_MCT_U232=y
 CONFIG_USB_SERIAL_MXUPORT=y
 CONFIG_USB_SERIAL_PL2303=y
-CONFIG_USB_SERIAL_SIERRAWIRELESS=y
 CONFIG_USB_SERIAL_OPTION=y
 CONFIG_USB_USBIO=y
 CONFIG_TYPEC=y
@@ -837,19 +831,9 @@ CONFIG_LEDS_BRIGHTNESS_HW_CHANGED=y
 CONFIG_LEDS_PWM=y
 CONFIG_LEDS_USER=y
 CONFIG_LEDS_PWM_MULTICOLOR=y
-CONFIG_LEDS_TRIGGER_TIMER=y
-CONFIG_LEDS_TRIGGER_ONESHOT=y
-CONFIG_LEDS_TRIGGER_HEARTBEAT=y
 CONFIG_LEDS_TRIGGER_BACKLIGHT=y
-CONFIG_LEDS_TRIGGER_CPU=y
-CONFIG_LEDS_TRIGGER_ACTIVITY=y
 CONFIG_LEDS_TRIGGER_DEFAULT_ON=y
-CONFIG_LEDS_TRIGGER_TRANSIENT=y
-CONFIG_LEDS_TRIGGER_CAMERA=y
 CONFIG_LEDS_TRIGGER_PANIC=y
-CONFIG_LEDS_TRIGGER_NETDEV=y
-CONFIG_LEDS_TRIGGER_PATTERN=y
-CONFIG_LEDS_TRIGGER_TTY=y
 CONFIG_EDAC=y
 CONFIG_EDAC_GHES=y
 CONFIG_EDAC_IGEN6=y
@@ -935,8 +919,7 @@ CONFIG_INTEL_RAPL_TPMI=y
 CONFIG_USB4=y
 # CONFIG_BLK_DEV_PMEM is not set
 # CONFIG_BTT is not set
-CONFIG_COUNTER=y
-CONFIG_INTERRUPT_CNT=y
+# CONFIG_NVDIMM_DAX is not set
 CONFIG_VALIDATE_FS_PARSER=y
 CONFIG_EXT4_FS=y
 CONFIG_EXT4_FS_POSIX_ACL=y
@@ -959,7 +942,6 @@ CONFIG_FS_VERITY=y
 CONFIG_FS_VERITY_BUILTIN_SIGNATURES=y
 CONFIG_FANOTIFY=y
 CONFIG_FANOTIFY_ACCESS_PERMISSIONS=y
-CONFIG_QUOTA=y
 CONFIG_QUOTA_NETLINK_INTERFACE=y
 CONFIG_AUTOFS_FS=y
 CONFIG_FUSE_FS=y
@@ -979,6 +961,7 @@ CONFIG_PROC_KCORE=y
 CONFIG_PROC_VMCORE_DEVICE_DUMP=y
 CONFIG_TMPFS_POSIX_ACL=y
 CONFIG_TMPFS_INODE64=y
+CONFIG_TMPFS_QUOTA=y
 CONFIG_HUGETLBFS=y
 CONFIG_EFIVAR_FS=y
 CONFIG_ECRYPT_FS=y
@@ -1138,6 +1121,7 @@ CONFIG_PACKING=y
 # CONFIG_XZ_DEC_SPARC is not set
 # CONFIG_XZ_DEC_RISCV is not set
 CONFIG_SWIOTLB_DYNAMIC=y
+CONFIG_DMA_CMA=y
 CONFIG_IRQ_POLL=y
 CONFIG_FONTS=y
 CONFIG_FONT_8x8=y
@@ -1168,6 +1152,7 @@ CONFIG_BOOTPARAM_HARDLOCKUP_PANIC=y
 CONFIG_WQ_WATCHDOG=y
 CONFIG_WQ_CPU_INTENSIVE_REPORT=y
 CONFIG_SCHEDSTATS=y
+CONFIG_NMI_CHECK_CPU=y
 CONFIG_STACKTRACE=y
 CONFIG_RCU_CPU_STALL_TIMEOUT=60
 # CONFIG_RCU_TRACE is not set
-- 
2.53.0