On Tue, 1 Nov 2022, at 00:18, John Thomson wrote: > I may have got lucky. it appears as though this is all I need to boot: > (against 6.1-rc3), and with the Bootlin toolchain. Will test my other > build system as well. > > --- a/mm/slub.c > +++ b/mm/slub.c > @@ -3276,7 +3276,7 @@ static void *__slab_alloc(struct kmem_cache *s, > gfp_t gfpflags, int node, > c = slub_get_cpu_ptr(s->cpu_slab); > #endif > > - p = ___slab_alloc(s, gfpflags, node, addr, c, orig_size); > + p = ___slab_alloc(s, gfpflags, node, addr, c, 0); > #ifdef CONFIG_PREEMPT_COUNT > slub_put_cpu_ptr(s->cpu_slab); > #endif Tested that with and without SLUB_DEBUG Testing without SLUB_DEBUG below: With this change on 6.1-rc3: diff --git a/mm/slub.c b/mm/slub.c index 157527d7101b..5fdb7609bb9e 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -3410,6 +3410,8 @@ static __always_inline void *__kmem_cache_alloc_lru(struct kmem_cache *s, struct list_lru *lru, gfp_t gfpflags) { + + pr_warn("SLUB: __slab_alloc from slab_alloc s->object_size=%d\n", s->object_size); void *ret = slab_alloc(s, lru, gfpflags, _RET_IP_, s->object_size); trace_kmem_cache_alloc(_RET_IP_, ret, s, gfpflags, NUMA_NO_NODE); UART & boot stops here: transfer started ......................................... transfer ok, time=2.00s setting up elf image... OK jumping to kernel code zimage at: 80B842A0 810B4BE4 Uncompressing Linux at load address 80001000 Copy device tree to address 80B80EE0 Now, booting the kernel... [ 0.000000] Linux version 6.1.0-rc3+ (john@john) (mipsel-buildroot-linux-gnu-gcc.br_real (Buildroot 2021.11-4428-g6b6741b) 12.2.0, GNU ld (GNU Binutils) 2.39) #34 SMP Tue Nov 1 12:33:10 AEST 2022 [ 0.000000] Overriding previously set SMP ops [ 0.000000] SoC Type: MediaTek MT7621 ver:1 eco:3 [ 0.000000] printk: bootconsole [early0] enabled [ 0.000000] CPU0 revision is: 0001992f (MIPS 1004Kc) [ 0.000000] MIPS: machine is MikroTik RouterBOARD 760iGS [ 0.000000] Initrd not found or empty - disabling initrd [ 0.000000] VPE topology {2,2} total 4 [ 0.000000] Primary instruction cache 32kB, VIPT, 4-way, linesize 32 bytes. [ 0.000000] Primary data cache 32kB, 4-way, PIPT, no aliases, linesize 32 bytes [ 0.000000] MIPS secondary cache 256kB, 8-way, linesize 32 bytes. [ 0.000000] Zone ranges: [ 0.000000] Normal [mem 0x0000000000000000-0x000000000fffffff] [ 0.000000] HighMem empty [ 0.000000] Movable zone start for each node [ 0.000000] Early memory node ranges [ 0.000000] node 0: [mem 0x0000000000000000-0x000000000fffffff] [ 0.000000] Initmem setup node 0 [mem 0x0000000000000000-0x000000000fffffff] [ 0.000000] percpu: Embedded 11 pages/cpu s16064 r8192 d20800 u45056 [ 0.000000] Built 1 zonelists, mobility grouping on. Total pages: 64960 [ 0.000000] Kernel command line: earlyprintk=ttyS0,115200 console=ttyS0,115200 rootfstype=squashfs,jffs2 [ 0.000000] Unknown kernel command line parameters "earlyprintk=ttyS0,115200", will be passed to user space. [ 0.000000] Dentry cache hash table entries: 32768 (order: 5, 131072 bytes, linear) [ 0.000000] Inode-cache hash table entries: 16384 (order: 4, 65536 bytes, linear) [ 0.000000] Writing ErrCtl register=00011146 [ 0.000000] Readback ErrCtl register=00011146 [ 0.000000] mem auto-init: stack:off, heap alloc:off, heap free:off [ 0.000000] Memory: 246284K/262144K available (7417K kernel code, 630K rwdata, 1304K rodata, 3500K init, 245K bss, 15860K reserved, 0K cma-reserved, 0K highmem) [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=132 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=132 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=132 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=132 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=132 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=132 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=132 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=132 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=132 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=132 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=132 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=132 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=132 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=132 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=132 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=132 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=132 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=132 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=132 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=132 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=132 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=132 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=132 [ 0.000000] SLUB: HWalign=32, Order=0-3, MinObjects=0, CPUs=4, Nodes=1 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=132 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=32 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=132 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=128 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=132 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=132 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=128 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=128 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=300 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=128 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=128 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=128 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=128 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=128 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=128 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=128 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=128 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=128 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=128 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=128 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=128 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=128 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=128 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=128 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=128 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=128 [ 0.000000] rcu: Hierarchical RCU implementation. [ 0.000000] Tracing variant of Tasks RCU enabled. [ 0.000000] rcu: RCU calculated value of scheduler-enlistment delay is 10 jiffies. [ 0.000000] NR_IRQS: 256 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=128 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=128 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=128 [ 0.000000] rcu: srcu_init: Setting srcu_struct sizes based on contention. [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=128 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=128 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=128 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=128 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=128 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=128 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=512 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=128 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=128 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=128 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=512 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=128 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=128 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=256 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=128 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=256 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=128 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=256 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=128 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=128 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=128 [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=128 [ 0.000000] clocksource: GIC: mask: 0xffffffffffffffff max_cycles: 0xcaf478abb4, max_idle_ns: 440795247997 ns [ 0.000000] SLUB: __slab_alloc from slab_alloc s->object_size=256 [ 0.000004] sched_clock: 64 bits at 880MHz, resolution 1ns, wraps every 4398046511103ns This change, and kernel boots fine: diff --git a/mm/slub.c b/mm/slub.c index 157527d7101b..e9677c04d19c 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -3410,7 +3410,11 @@ static __always_inline void *__kmem_cache_alloc_lru(struct kmem_cache *s, struct list_lru *lru, gfp_t gfpflags) { - void *ret = slab_alloc(s, lru, gfpflags, _RET_IP_, s->object_size); + + /* + pr_warn("SLUB: __slab_alloc from slab_alloc s->object_size=%d\n", s->object_size); + void *ret = slab_alloc(s, lru, gfpflags, _RET_IP_, s->object_size);*/ + void *ret = slab_alloc(s, lru, gfpflags, _RET_IP_, 0); trace_kmem_cache_alloc(_RET_IP_, ret, s, gfpflags, NUMA_NO_NODE); Cheers, -- John Thomson