[PATCH] misc/genwqe: get rid of atomic allocations

From: Sebastian Ott
Date: Tue Sep 29 2015 - 12:24:09 EST


Hi,

we received reports of failed allocations in genwqe code:

[ 733.550955] genwqe_gzip: page allocation failure: order:1, mode:0x20
[ 733.550964] CPU: 2 PID: 1846 Comm: genwqe_gzip Not tainted 4.3.0-rc3-00042-g3225031 #78
[ 733.550968] 000000002782b830 000000002782b8c0 0000000000000002 0000000000000000
000000002782b960 000000002782b8d8 000000002782b8d8 00000000001134a0
0000000000000000 0000000000892b2a 0000000000871d0a 000000000000000b
000000002782b920 000000002782b8c0 0000000000000000 0000000000000000
0000000000000000 00000000001134a0 000000002782b8c0 000000002782b920
[ 733.551003] Call Trace:
[ 733.551013] ([<0000000000113388>] show_trace+0xf8/0x158)
[ 733.551018] [<0000000000113452>] show_stack+0x6a/0xe8
[ 733.551024] [<00000000004611d4>] dump_stack+0x7c/0xd8
[ 733.551031] [<000000000024dc22>] warn_alloc_failed+0xda/0x150
[ 733.551036] [<000000000025268e>] __alloc_pages_nodemask+0x94e/0xbc0
[ 733.551041] [<000000000012bcd8>] s390_dma_alloc+0x70/0x1a0
[ 733.551054] [<000003ff804d8e8c>] __genwqe_alloc_consistent+0x84/0xd0 [genwqe_card]
[ 733.551063] [<000003ff804d90c2>] genwqe_alloc_sync_sgl+0x13a/0x328 [genwqe_card]
[ 733.551066] [<000003ff804d41a0>] do_execute_ddcb+0x1f8/0x388 [genwqe_card]
[ 733.551069] [<000003ff804d48c8>] genwqe_ioctl+0x598/0xd50 [genwqe_card]
[ 733.551072] [<00000000002cc90c>] do_vfs_ioctl+0x3f4/0x590
[ 733.551074] [<00000000002ccb46>] SyS_ioctl+0x9e/0xb0
[ 733.551078] [<00000000006c8166>] system_call+0xd6/0x258
[ 733.551080] [<000003fffd25819a>] 0x3fffd25819a
[ 733.551082] no locks held by genwqe_gzip/1846.

This specific allocation and some others in genwqe are unnecessary flagged
as atomic.

Regards,
Sebastian
---->8
misc/genwqe: get rid of atomic allocations

All of genwqe's atomic allocations happen in a context where it's allowed
to sleep. Change these to use GFP_KERNEL.

Signed-off-by: Sebastian Ott <sebott@xxxxxxxxxxxxxxxxxx>
---
drivers/misc/genwqe/card_ddcb.c | 2 +-
drivers/misc/genwqe/card_dev.c | 4 ++--
drivers/misc/genwqe/card_utils.c | 5 +++--
3 files changed, 6 insertions(+), 5 deletions(-)

--- a/drivers/misc/genwqe/card_ddcb.c
+++ b/drivers/misc/genwqe/card_ddcb.c
@@ -203,7 +203,7 @@ struct genwqe_ddcb_cmd *ddcb_requ_alloc(
{
struct ddcb_requ *req;

- req = kzalloc(sizeof(*req), GFP_ATOMIC);
+ req = kzalloc(sizeof(*req), GFP_KERNEL);
if (!req)
return NULL;

--- a/drivers/misc/genwqe/card_dev.c
+++ b/drivers/misc/genwqe/card_dev.c
@@ -449,7 +449,7 @@ static int genwqe_mmap(struct file *filp
if (get_order(vsize) > MAX_ORDER)
return -ENOMEM;

- dma_map = kzalloc(sizeof(struct dma_mapping), GFP_ATOMIC);
+ dma_map = kzalloc(sizeof(struct dma_mapping), GFP_KERNEL);
if (dma_map == NULL)
return -ENOMEM;

@@ -785,7 +785,7 @@ static int genwqe_pin_mem(struct genwqe_
map_addr = (m->addr & PAGE_MASK);
map_size = round_up(m->size + (m->addr & ~PAGE_MASK), PAGE_SIZE);

- dma_map = kzalloc(sizeof(struct dma_mapping), GFP_ATOMIC);
+ dma_map = kzalloc(sizeof(struct dma_mapping), GFP_KERNEL);
if (dma_map == NULL)
return -ENOMEM;

--- a/drivers/misc/genwqe/card_utils.c
+++ b/drivers/misc/genwqe/card_utils.c
@@ -220,7 +220,8 @@ void *__genwqe_alloc_consistent(struct g
if (get_order(size) > MAX_ORDER)
return NULL;

- return pci_alloc_consistent(cd->pci_dev, size, dma_handle);
+ return dma_alloc_coherent(&cd->pci_dev->dev, size, dma_handle,
+ GFP_KERNEL);
}

void __genwqe_free_consistent(struct genwqe_dev *cd, size_t size,
@@ -229,7 +230,7 @@ void __genwqe_free_consistent(struct gen
if (vaddr == NULL)
return;

- pci_free_consistent(cd->pci_dev, size, vaddr, dma_handle);
+ dma_free_coherent(&cd->pci_dev->dev, size, vaddr, dma_handle);
}

static void genwqe_unmap_pages(struct genwqe_dev *cd, dma_addr_t *dma_list,

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