Merge tag 'mm-nonmm-stable-2025-08-03-12-47' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull non-MM updates from Andrew Morton:
 "Significant patch series in this pull request:

   - "squashfs: Remove page->mapping references" (Matthew Wilcox) gets
     us closer to being able to remove page->mapping

   - "relayfs: misc changes" (Jason Xing) does some maintenance and
     minor feature addition work in relayfs

   - "kdump: crashkernel reservation from CMA" (Jiri Bohac) switches
     us from static preallocation of the kdump crashkernel's working
     memory over to dynamic allocation. So the difficulty of a-priori
     estimation of the second kernel's needs is removed and the first
     kernel obtains extra memory

   - "generalize panic_print's dump function to be used by other
     kernel parts" (Feng Tang) implements some consolidation and
     rationalization of the various ways in which a failing kernel
     splats information at the operator

* tag 'mm-nonmm-stable-2025-08-03-12-47' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (80 commits)
  tools/getdelays: add backward compatibility for taskstats version
  kho: add test for kexec handover
  delaytop: enhance error logging and add PSI feature description
  samples: Kconfig: fix spelling mistake "instancess" -> "instances"
  fat: fix too many log in fat_chain_add()
  scripts/spelling.txt: add notifer||notifier to spelling.txt
  xen/xenbus: fix typo "notifer"
  net: mvneta: fix typo "notifer"
  drm/xe: fix typo "notifer"
  cxl: mce: fix typo "notifer"
  KVM: x86: fix typo "notifer"
  MAINTAINERS: add maintainers for delaytop
  ucount: use atomic_long_try_cmpxchg() in atomic_long_inc_below()
  ucount: fix atomic_long_inc_below() argument type
  kexec: enable CMA based contiguous allocation
  stackdepot: make max number of pools boot-time configurable
  lib/xxhash: remove unused functions
  init/Kconfig: restore CONFIG_BROKEN help text
  lib/raid6: update recov_rvv.c zero page usage
  docs: update docs after introducing delaytop
  ...

Author: torvalds

.mailmap

@@ -673,6 +673,7 @@ Muchun Song <[email protected]> <[email protected]>
 Ross Zwisler <[email protected]> <[email protected]>
 Rudolf Marek <[email protected]>
 Rui Saraiva <[email protected]>
+Sachin Mokashi <[email protected]> <[email protected]>
 Sachin P Sant <[email protected]>
 Sai Prakash Ranjan <[email protected]> <[email protected]>
 Sakari Ailus <[email protected]> <[email protected]>

Documentation/accounting/delay-accounting.rst

@@ -131,3 +131,59 @@ Get IO accounting for pid 1, it works only with -p::
 	linuxrc: read=65536, write=0, cancelled_write=0
 
 The above command can be used with -v to get more debug information.
+
+After the system starts, use `delaytop` to get the system-wide delay information,
+which includes system-wide PSI information and Top-N high-latency tasks.
+
+`delaytop` supports sorting by CPU latency in descending order by default,
+displays the top 20 high-latency tasks by default, and refreshes the latency
+data every 2 seconds by default.
+
+Get PSI information and Top-N tasks delay, since system boot::
+
+	bash# ./delaytop
+	System Pressure Information: (avg10/avg60/avg300/total)
+	CPU some:       0.0%/   0.0%/   0.0%/     345(ms)
+	CPU full:       0.0%/   0.0%/   0.0%/       0(ms)
+	Memory full:    0.0%/   0.0%/   0.0%/       0(ms)
+	Memory some:    0.0%/   0.0%/   0.0%/       0(ms)
+	IO full:        0.0%/   0.0%/   0.0%/      65(ms)
+	IO some:        0.0%/   0.0%/   0.0%/      79(ms)
+	IRQ full:       0.0%/   0.0%/   0.0%/       0(ms)
+	Top 20 processes (sorted by CPU delay):
+	  PID   TGID  COMMAND          CPU(ms)  IO(ms) SWAP(ms) RCL(ms) THR(ms) CMP(ms)  WP(ms) IRQ(ms)
+	----------------------------------------------------------------------------------------------
+	  161    161  zombie_memcg_re   1.40    0.00    0.00    0.00    0.00    0.00    0.00    0.00
+	  130    130  blkcg_punt_bio    1.37    0.00    0.00    0.00    0.00    0.00    0.00    0.00
+	  444    444  scsi_tmf_0        0.73    0.00    0.00    0.00    0.00    0.00    0.00    0.00
+	 1280   1280  rsyslogd          0.53    0.04    0.00    0.00    0.00    0.00    0.00    0.00
+	   12     12  ksoftirqd/0       0.47    0.00    0.00    0.00    0.00    0.00    0.00    0.00
+	 1277   1277  nbd-server        0.44    0.00    0.00    0.00    0.00    0.00    0.00    0.00
+	  308    308  kworker/2:2-sys   0.41    0.00    0.00    0.00    0.00    0.00    0.00    0.00
+	   55     55  netns             0.36    0.00    0.00    0.00    0.00    0.00    0.00    0.00
+	 1187   1187  acpid             0.31    0.03    0.00    0.00    0.00    0.00    0.00    0.00
+	 6184   6184  kworker/1:2-sys   0.24    0.00    0.00    0.00    0.00    0.00    0.00    0.00
+	  186    186  kaluad            0.24    0.00    0.00    0.00    0.00    0.00    0.00    0.00
+	   18     18  ksoftirqd/1       0.24    0.00    0.00    0.00    0.00    0.00    0.00    0.00
+	  185    185  kmpath_rdacd      0.23    0.00    0.00    0.00    0.00    0.00    0.00    0.00
+	  190    190  kstrp             0.23    0.00    0.00    0.00    0.00    0.00    0.00    0.00
+	 2759   2759  agetty            0.20    0.03    0.00    0.00    0.00    0.00    0.00    0.00
+	 1190   1190  kworker/0:3-sys   0.19    0.00    0.00    0.00    0.00    0.00    0.00    0.00
+	 1272   1272  sshd              0.15    0.04    0.00    0.00    0.00    0.00    0.00    0.00
+	 1156   1156  license           0.15    0.11    0.00    0.00    0.00    0.00    0.00    0.00
+	  134    134  md                0.13    0.00    0.00    0.00    0.00    0.00    0.00    0.00
+	 6142   6142  kworker/3:2-xfs   0.13    0.00    0.00    0.00    0.00    0.00    0.00    0.00
+
+Dynamic interactive interface of delaytop::
+
+	# ./delaytop -p pid
+	Print delayacct stats
+
+	# ./delaytop -P num
+	Display the top N tasks
+
+	# ./delaytop -n num
+	Set delaytop refresh frequency (num times)
+
+	# ./delaytop -d secs
+	Specify refresh interval as secs

Documentation/admin-guide/kdump/kdump.rst

@@ -311,6 +311,27 @@ crashkernel syntax
 
             crashkernel=0,low
 
+4) crashkernel=size,cma
+
+	Reserve additional crash kernel memory from CMA. This reservation is
+	usable by the first system's userspace memory and kernel movable
+	allocations (memory balloon, zswap). Pages allocated from this memory
+	range will not be included in the vmcore so this should not be used if
+	dumping of userspace memory is intended and it has to be expected that
+	some movable kernel pages may be missing from the dump.
+
+	A standard crashkernel reservation, as described above, is still needed
+	to hold the crash kernel and initrd.
+
+	This option increases the risk of a kdump failure: DMA transfers
+	configured by the first kernel may end up corrupting the second
+	kernel's memory.
+
+	This reservation method is intended for systems that can't afford to
+	sacrifice enough memory for standard crashkernel reservation and where
+	less reliable and possibly incomplete kdump is preferable to no kdump at
+	all.
+
 Boot into System Kernel
 -----------------------
 1) Update the boot loader (such as grub, yaboot, or lilo) configuration

Documentation/admin-guide/kernel-parameters.txt

@@ -994,6 +994,28 @@
 			0: to disable low allocation.
 			It will be ignored when crashkernel=X,high is not used
 			or memory reserved is below 4G.
+	crashkernel=size[KMG],cma
+			[KNL, X86] Reserve additional crash kernel memory from
+			CMA. This reservation is usable by the first system's
+			userspace memory and kernel movable allocations (memory
+			balloon, zswap). Pages allocated from this memory range
+			will not be included in the vmcore so this should not
+			be used if dumping of userspace memory is intended and
+			it has to be expected that some movable kernel pages
+			may be missing from the dump.
+
+			A standard crashkernel reservation, as described above,
+			is still needed to hold the crash kernel and initrd.
+
+			This option increases the risk of a kdump failure: DMA
+			transfers configured by the first kernel may end up
+			corrupting the second kernel's memory.
+
+			This reservation method is intended for systems that
+			can't afford to sacrifice enough memory for standard
+			crashkernel reservation and where less reliable and
+			possibly incomplete kdump is preferable to no kdump at
+			all.
 
 	cryptomgr.notests
 			[KNL] Disable crypto self-tests
@@ -4557,14 +4579,33 @@
 			bit 2: print timer info
 			bit 3: print locks info if CONFIG_LOCKDEP is on
 			bit 4: print ftrace buffer
-			bit 5: print all printk messages in buffer
+			bit 5: replay all messages on consoles at the end of panic
 			bit 6: print all CPUs backtrace (if available in the arch)
 			bit 7: print only tasks in uninterruptible (blocked) state
 			*Be aware* that this option may print a _lot_ of lines,
 			so there are risks of losing older messages in the log.
 			Use this option carefully, maybe worth to setup a
 			bigger log buffer with "log_buf_len" along with this.
 
+	panic_sys_info= A comma separated list of extra information to be dumped
+                        on panic.
+                        Format: val[,val...]
+                        Where @val can be any of the following:
+
+                        tasks:          print all tasks info
+                        mem:            print system memory info
+			timers:         print timers info
+                        locks:          print locks info if CONFIG_LOCKDEP is on
+                        ftrace:         print ftrace buffer
+                        all_bt:         print all CPUs backtrace (if available in the arch)
+                        blocked_tasks:  print only tasks in uninterruptible (blocked) state
+
+                        This is a human readable alternative to the 'panic_print' option.
+
+	panic_console_replay
+			When panic happens, replay all kernel messages on
+			consoles at the end of panic.
+
 	parkbd.port=	[HW] Parallel port number the keyboard adapter is
 			connected to, default is 0.
 			Format: <parport#>
@@ -7032,6 +7073,11 @@
 			consumed by the stack hash table. By default this is set
 			to false.
 
+	stack_depot_max_pools= [KNL,EARLY]
+			Specify the maximum number of pools to use for storing
+			stack traces. Pools are allocated on-demand up to this
+			limit. Default value is 8191 pools.
+
 	stacktrace	[FTRACE]
 			Enabled the stack tracer on boot up.
 

Documentation/admin-guide/sysctl/kernel.rst

@@ -890,7 +890,7 @@ bit 1  print system memory info
 bit 2  print timer info
 bit 3  print locks info if ``CONFIG_LOCKDEP`` is on
 bit 4  print ftrace buffer
-bit 5  print all printk messages in buffer
+bit 5  replay all messages on consoles at the end of panic
 bit 6  print all CPUs backtrace (if available in the arch)
 bit 7  print only tasks in uninterruptible (blocked) state
 =====  ============================================
@@ -900,6 +900,24 @@ So for example to print tasks and memory info on panic, user can::
   echo 3 > /proc/sys/kernel/panic_print
 
 
+panic_sys_info
+==============
+
+A comma separated list of extra information to be dumped on panic,
+for example, "tasks,mem,timers,...".  It is a human readable alternative
+to 'panic_print'. Possible values are:
+
+=============   ===================================================
+tasks           print all tasks info
+mem             print system memory info
+timer           print timers info
+lock            print locks info if CONFIG_LOCKDEP is on
+ftrace          print ftrace buffer
+all_bt          print all CPUs backtrace (if available in the arch)
+blocked_tasks   print only tasks in uninterruptible (blocked) state
+=============   ===================================================
+
+
 panic_on_rcu_stall
 ==================
 

MAINTAINERS

@@ -13544,6 +13544,7 @@ F:	Documentation/admin-guide/mm/kho.rst
 F:	Documentation/core-api/kho/*
 F:	include/linux/kexec_handover.h
 F:	kernel/kexec_handover.c
+F:	tools/testing/selftests/kho/
 
 KEYS-ENCRYPTED
 M:	Mimi Zohar <[email protected]>
@@ -19741,6 +19742,16 @@ S:	Maintained
 F:	include/linux/delayacct.h
 F:	kernel/delayacct.c
 
+TASK DELAY MONITORING TOOLS
+M:	Andrew Morton <[email protected]>
+M:	Wang Yaxin <[email protected]>
+M:	Fan Yu <[email protected]>
+L:	[email protected]
+S:	Maintained
+F:	Documentation/accounting/delay-accounting.rst
+F:	tools/accounting/delaytop.c
+F:	tools/accounting/getdelays.c
+
 PERFORMANCE EVENTS SUBSYSTEM
 M:	Peter Zijlstra <[email protected]>
 M:	Ingo Molnar <[email protected]>
@@ -23382,6 +23393,7 @@ F:	drivers/md/md*
 F:	drivers/md/raid*
 F:	include/linux/raid/
 F:	include/uapi/linux/raid/
+F:	lib/raid6/
 
 SOLIDRUN CLEARFOG SUPPORT
 M:	Russell King <[email protected]>

arch/alpha/kernel/core_marvel.c

@@ -17,6 +17,7 @@
 #include <linux/vmalloc.h>
 #include <linux/mc146818rtc.h>
 #include <linux/rtc.h>
+#include <linux/string.h>
 #include <linux/module.h>
 #include <linux/memblock.h>
 
@@ -79,10 +80,12 @@ mk_resource_name(int pe, int port, char *str)
 {
 	char tmp[80];
 	char *name;
-	
-	sprintf(tmp, "PCI %s PE %d PORT %d", str, pe, port);
-	name = memblock_alloc_or_panic(strlen(tmp) + 1, SMP_CACHE_BYTES);
-	strcpy(name, tmp);
+	size_t sz;
+
+	sz = scnprintf(tmp, sizeof(tmp), "PCI %s PE %d PORT %d", str, pe, port);
+	sz += 1; /* NUL terminator */
+	name = memblock_alloc_or_panic(sz, SMP_CACHE_BYTES);
+	strscpy(name, tmp, sz);
 
 	return name;
 }

arch/arm/kernel/setup.c

@@ -1004,7 +1004,7 @@ static void __init reserve_crashkernel(void)
 	total_mem = get_total_mem();
 	ret = parse_crashkernel(boot_command_line, total_mem,
 				&crash_size, &crash_base,
-				NULL, NULL);
+				NULL, NULL, NULL);
 	/* invalid value specified or crashkernel=0 */
 	if (ret || !crash_size)
 		return;

arch/arm64/mm/init.c

@@ -106,7 +106,7 @@ static void __init arch_reserve_crashkernel(void)
 
 	ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
 				&crash_size, &crash_base,
-				&low_size, &high);
+				&low_size, NULL, &high);
 	if (ret)
 		return;
 

arch/loongarch/kernel/setup.c

@@ -265,7 +265,7 @@ static void __init arch_reserve_crashkernel(void)
 		return;
 
 	ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
-				&crash_size, &crash_base, &low_size, &high);
+				&crash_size, &crash_base, &low_size, NULL, &high);
 	if (ret)
 		return;