Messages in this thread | | | Date | Mon, 13 Dec 2021 08:24:21 -0600 | Subject | Re: [PATCH v3 5/5] mm/slub: do not create dma-kmalloc if no managed pages in DMA zone | From | john.p.donnelly@oracle ... |
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On 12/13/21 6:27 AM, Baoquan He wrote: > Dma-kmalloc will be created as long as CONFIG_ZONE_DMA is enabled. > However, it will fail if DMA zone has no managed pages. The failure > can be seen in kdump kernel of x86_64 as below: > > CPU: 0 PID: 65 Comm: kworker/u2:1 Not tainted 5.14.0-rc2+ #9 > Hardware name: Intel Corporation SandyBridge Platform/To be filled by O.E.M., BIOS RMLSDP.86I.R2.28.D690.1306271008 06/27/2013 > Workqueue: events_unbound async_run_entry_fn > Call Trace: > dump_stack_lvl+0x57/0x72 > warn_alloc.cold+0x72/0xd6 > __alloc_pages_slowpath.constprop.0+0xf56/0xf70 > __alloc_pages+0x23b/0x2b0 > allocate_slab+0x406/0x630 > ___slab_alloc+0x4b1/0x7e0 > ? sr_probe+0x200/0x600 > ? lock_acquire+0xc4/0x2e0 > ? fs_reclaim_acquire+0x4d/0xe0 > ? lock_is_held_type+0xa7/0x120 > ? sr_probe+0x200/0x600 > ? __slab_alloc+0x67/0x90 > __slab_alloc+0x67/0x90 > ? sr_probe+0x200/0x600 > ? sr_probe+0x200/0x600 > kmem_cache_alloc_trace+0x259/0x270 > sr_probe+0x200/0x600 > ...... > bus_probe_device+0x9f/0xb0 > device_add+0x3d2/0x970 > ...... > __scsi_add_device+0xea/0x100 > ata_scsi_scan_host+0x97/0x1d0 > async_run_entry_fn+0x30/0x130 > process_one_work+0x2b0/0x5c0 > worker_thread+0x55/0x3c0 > ? process_one_work+0x5c0/0x5c0 > kthread+0x149/0x170 > ? set_kthread_struct+0x40/0x40 > ret_from_fork+0x22/0x30 > Mem-Info: > ...... > > The above failure happened when calling kmalloc() to allocate buffer with > GFP_DMA. It requests to allocate slab page from DMA zone while no managed > pages in there. > sr_probe() > --> get_capabilities() > --> buffer = kmalloc(512, GFP_KERNEL | GFP_DMA); > > The DMA zone should be checked if it has managed pages, then try to create > dma-kmalloc. > > Fixes: 6f599d84231f ("x86/kdump: Always reserve the low 1M when the crashkernel option is specified") > Cc: stable@vger.kernel.org > Signed-off-by: Baoquan He <bhe@redhat.com>
Acked-by: John Donnelly <john.p.donnelly@oracle.com> Tested-by: John Donnelly <john.p.donnelly@oracle.com>
> Cc: Christoph Lameter <cl@linux.com> > Cc: Pekka Enberg <penberg@kernel.org> > Cc: David Rientjes <rientjes@google.com> > Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> > Cc: Vlastimil Babka <vbabka@suse.cz> > --- > mm/slab_common.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/mm/slab_common.c b/mm/slab_common.c > index e5d080a93009..ae4ef0f8903a 100644 > --- a/mm/slab_common.c > +++ b/mm/slab_common.c > @@ -878,6 +878,9 @@ void __init create_kmalloc_caches(slab_flags_t flags) > { > int i; > enum kmalloc_cache_type type; > +#ifdef CONFIG_ZONE_DMA > + bool managed_dma; > +#endif > > /* > * Including KMALLOC_CGROUP if CONFIG_MEMCG_KMEM defined > @@ -905,10 +908,16 @@ void __init create_kmalloc_caches(slab_flags_t flags) > slab_state = UP; > > #ifdef CONFIG_ZONE_DMA > + managed_dma = has_managed_dma(); > + > for (i = 0; i <= KMALLOC_SHIFT_HIGH; i++) { > struct kmem_cache *s = kmalloc_caches[KMALLOC_NORMAL][i]; > > if (s) { > + if (!managed_dma) { > + kmalloc_caches[KMALLOC_DMA][i] = kmalloc_caches[KMALLOC_NORMAL][i]; > + continue; > + } > kmalloc_caches[KMALLOC_DMA][i] = create_kmalloc_cache( > kmalloc_info[i].name[KMALLOC_DMA], > kmalloc_info[i].size,
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