Hi Will,
Seems that commit a44a9791e778d9ccda50d5534028ed4057a9a45b
(iommu/arm-smmu: use mutex instead of spinlock for locking page tables)
introduced a regression.
At least I've hit
BUG: scheduling while atomic: ksoftirqd/0/3/0x00000100
and after turning on CONFIG_DEBUG_ATOMIC_SLEEP I get
BUG: sleeping function called from invalid context at
kernel/locking/mutex.c:96
in_atomic(): 1, irqs_disabled(): 128, pid: 1, name: swapper/0
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.13.0-00013-gd414667 #411
[<c0014740>] (unwind_backtrace+0x0/0xf8) from [<c00115b0>]
(show_stack+0x10/0x14)
[<c00115b0>] (show_stack+0x10/0x14) from [<c057f12c>] (dump_stack+0x74/0xa8)
[<c057f12c>] (dump_stack+0x74/0xa8) from [<c0583460>] (mutex_lock+0x18/0x64)
[<c0583460>] (mutex_lock+0x18/0x64) from [<c042a5fc>]
(arm_smmu_handle_mapping+0xfc/0x644)
[<c042a5fc>] (arm_smmu_handle_mapping+0xfc/0x644) from [<c0429674>]
(iommu_map+0xf0/0x148)
[<c0429674>] (iommu_map+0xf0/0x148) from [<c00199c8>]
(__map_sg_chunk+0x208/0x414)
[<c00199c8>] (__map_sg_chunk+0x208/0x414) from [<c0019d50>]
(__iommu_map_sg+0x17c/0x208)
[<c0019d50>] (__iommu_map_sg+0x17c/0x208) from [<c0019df8>]
(arm_iommu_map_sg+0x1c/0x24)
[<c0019df8>] (arm_iommu_map_sg+0x1c/0x24) from [<c031edb4>]
(ata_qc_issue+0x258/0x370)
[<c031edb4>] (ata_qc_issue+0x258/0x370) from [<c0323b68>]
(ata_scsi_translate+0x90/0x150)
[<c0323b68>] (ata_scsi_translate+0x90/0x150) from [<c0327368>]
(ata_scsi_queuecmd+0x84/0x248)
[<c0327368>] (ata_scsi_queuecmd+0x84/0x248) from [<c0301ed8>]
(scsi_dispatch_cmd+0x94/0x134)
[<c0301ed8>] (scsi_dispatch_cmd+0x94/0x134) from [<c0307ecc>]
(scsi_request_fn+0x3dc/0x5dc)
[<c0307ecc>] (scsi_request_fn+0x3dc/0x5dc) from [<c0250034>]
(__blk_run_queue+0x34/0x44)
[<c0250034>] (__blk_run_queue+0x34/0x44) from [<c02539e0>]
(blk_queue_bio+0x178/0x26c)
[<c02539e0>] (blk_queue_bio+0x178/0x26c) from [<c02512a0>]
(generic_make_request+0xa8/0xc8)
[<c02512a0>] (generic_make_request+0xa8/0xc8) from [<c0251348>]
(submit_bio+0x88/0x134)
[<c0251348>] (submit_bio+0x88/0x134) from [<c0113938>]
(_submit_bh+0x1a4/0x254)
[<c0113938>] (_submit_bh+0x1a4/0x254) from [<c0114210>]
(ll_rw_block+0x94/0xec)
[<c0114210>] (ll_rw_block+0x94/0xec) from [<c0116078>]
(__breadahead+0x30/0x48)
[<c0116078>] (__breadahead+0x30/0x48) from [<c0171ca4>]
(__ext4_get_inode_loc+0x3c4/0x450)
[<c0171ca4>] (__ext4_get_inode_loc+0x3c4/0x450) from [<c017409c>]
(ext4_iget+0x60/0x96c)
[<c017409c>] (ext4_iget+0x60/0x96c) from [<c017cdc0>] (ext4_lookup+0x74/0x164)
[<c017cdc0>] (ext4_lookup+0x74/0x164) from [<c00f14a4>]
(lookup_real+0x20/0x50)
[<c00f14a4>] (lookup_real+0x20/0x50) from [<c00f235c>]
(__lookup_hash+0x34/0x44)
[<c00f235c>] (__lookup_hash+0x34/0x44) from [<c00f23a4>]
(lookup_slow+0x38/0x9c)
[<c00f23a4>] (lookup_slow+0x38/0x9c) from [<c00f30d4>]
(link_path_walk+0x308/0x7f0)
[<c00f30d4>] (link_path_walk+0x308/0x7f0) from [<c00f6384>]
(path_openat+0x8c/0x63c)
[<c00f6384>] (path_openat+0x8c/0x63c) from [<c00f6c34>]
(do_filp_open+0x2c/0x80)
[<c00f6c34>] (do_filp_open+0x2c/0x80) from [<c00edce0>] (open_exec+0x2c/0xf8)
[<c00edce0>] (open_exec+0x2c/0xf8) from [<c00eee98>] (do_execve+0x1a4/0x5a4)
[<c00eee98>] (do_execve+0x1a4/0x5a4) from [<c000873c>]
(try_to_run_init_process+0x1c/0x50)
[<c000873c>] (try_to_run_init_process+0x1c/0x50) from [<c057b7a0>]
(kernel_init+0xa8/0x110)
[<c057b7a0>] (kernel_init+0xa8/0x110) from [<c000e378>]
(ret_from_fork+0x14/0x3c)
After reverting commit a44a9791e778d9ccda50d5534028ed4057a9a45b I have
fewer warnings/errors but still I've seen:
BUG: sleeping function called from invalid context at mm/page_alloc.c:2679
in_atomic(): 1, irqs_disabled(): 128, pid: 0, name: swapper/0
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.13.0-00016-g6e90346 #413
[<c0014740>] (unwind_backtrace+0x0/0xf8) from [<c00115b0>]
(show_stack+0x10/0x14)
[<c00115b0>] (show_stack+0x10/0x14) from [<c057ea24>] (dump_stack+0x74/0xa8)
[<c057ea24>] (dump_stack+0x74/0xa8) from [<c00acc1c>]
(__alloc_pages_nodemask+0x174/0x930)
[<c00acc1c>] (__alloc_pages_nodemask+0x174/0x930) from [<c042a250>]
(arm_smmu_handle_mapping+0x470/0x66c)
[<c042a250>] (arm_smmu_handle_mapping+0x470/0x66c) from [<c0428e74>]
(iommu_map+0xf0/0x148)
[<c0428e74>] (iommu_map+0xf0/0x148) from [<c001935c>]
(__map_sg_chunk+0x198/0x2d4)
[<c001935c>] (__map_sg_chunk+0x198/0x2d4) from [<c0019614>]
(__iommu_map_sg+0x17c/0x208)
[<c0019614>] (__iommu_map_sg+0x17c/0x208) from [<c00196bc>]
(arm_iommu_map_sg+0x1c/0x24)
[<c00196bc>] (arm_iommu_map_sg+0x1c/0x24) from [<c031e5b4>]
(ata_qc_issue+0x258/0x370)
[<c031e5b4>] (ata_qc_issue+0x258/0x370) from [<c0323368>]
(ata_scsi_translate+0x90/0x150)
[<c0323368>] (ata_scsi_translate+0x90/0x150) from [<c0326b68>]
(ata_scsi_queuecmd+0x84/0x248)
[<c0326b68>] (ata_scsi_queuecmd+0x84/0x248) from [<c03016d8>]
(scsi_dispatch_cmd+0x94/0x134)
[<c03016d8>] (scsi_dispatch_cmd+0x94/0x134) from [<c03076cc>]
(scsi_request_fn+0x3dc/0x5dc)
[<c03076cc>] (scsi_request_fn+0x3dc/0x5dc) from [<c024f834>]
(__blk_run_queue+0x34/0x44)
[<c024f834>] (__blk_run_queue+0x34/0x44) from [<c024fabc>]
(blk_run_queue+0x1c/0x2c)
[<c024fabc>] (blk_run_queue+0x1c/0x2c) from [<c030638c>]
(scsi_run_queue+0xc4/0x240)
[<c030638c>] (scsi_run_queue+0xc4/0x240) from [<c0307f0c>]
(scsi_next_command+0x2c/0x38)
[<c0307f0c>] (scsi_next_command+0x2c/0x38) from [<c030815c>]
(scsi_io_completion+0x1fc/0x630)
[<c030815c>] (scsi_io_completion+0x1fc/0x630) from [<c0257a94>]
(blk_done_softirq+0x74/0x8c)
[<c0257a94>] (blk_done_softirq+0x74/0x8c) from [<c002856c>]
(__do_softirq+0xe4/0x210)
[<c002856c>] (__do_softirq+0xe4/0x210) from [<c00289c4>] (irq_exit+0xa0/0xec)
[<c00289c4>] (irq_exit+0xa0/0xec) from [<c000eb98>] (handle_IRQ+0x3c/0x90)
[<c000eb98>] (handle_IRQ+0x3c/0x90) from [<c0008538>]
(gic_handle_irq+0x28/0x5c)
[<c0008538>] (gic_handle_irq+0x28/0x5c) from [<c0012040>]
(__irq_svc+0x40/0x50)
Maybe that was the reason why the offending commit was introduced(?).
I think with the current code "atomic allocations" should be used when
IO page tables are created. With below patch I've not triggered above
errors.
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 429c95e..0418d69 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -1398,7 +1398,7 @@ static int arm_smmu_alloc_init_pte(struct arm_smmu_device
*smmu, pmd_t *pmd,
if (pmd_none(*pmd)) {
/* Allocate a new set of tables */
- pgtable_t table = alloc_page(PGALLOC_GFP);
+ pgtable_t table = alloc_page(GFP_ATOMIC);
if (!table)
return -ENOMEM;
@@ -1503,7 +1503,7 @@ static int arm_smmu_alloc_init_pmd(struct arm_smmu_device
*smmu, pud_t *pud,
#ifndef __PAGETABLE_PMD_FOLDED
if (pud_none(*pud)) {
- pmd = pmd_alloc_one(NULL, addr);
+ pmd = (pmd_t *) get_zeroed_page(GFP_ATOMIC);
if (!pmd)
return -ENOMEM;
} else
@@ -1532,7 +1532,7 @@ static int arm_smmu_alloc_init_pud(struct arm_smmu_device
*smmu, pgd_t *pgd,
#ifndef __PAGETABLE_PUD_FOLDED
if (pgd_none(*pgd)) {
- pud = pud_alloc_one(NULL, addr);
+ pud = (pud_t *) get_zeroed_page(GFP_ATOMIC);
if (!pud)
return -ENOMEM;
} else
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