We had a test-report where, under memory pressure, adding LUNs to the
systems would fail (the tests add LUNs strictly in sequence):
[ 5525.853432] scsi 0:0:1:1088045124: Direct-Access IBM 2107900
.148 PQ: 0 ANSI: 5
[ 5525.853826] scsi 0:0:1:1088045124: alua: supports implicit TPGS
[ 5525.853830] scsi 0:0:1:1088045124: alua: device
naa.6005076303ffd32700000000000044da port group 0 rel port 43
[ 5525.853931] sd 0:0:1:1088045124: Attached scsi generic sg10 type 0
[ 5525.854075] sd 0:0:1:1088045124: [sdk] Disabling DIF Type 1 protection
[ 5525.855495] sd 0:0:1:1088045124: [sdk] 2097152 512-byte logical blocks:
(1.07 GB/1.00 GiB)
[ 5525.855606] sd 0:0:1:1088045124: [sdk] Write Protect is off
[ 5525.855609] sd 0:0:1:1088045124: [sdk] Mode Sense: ed 00 00 08
[ 5525.855795] sd 0:0:1:1088045124: [sdk] Write cache: enabled, read cache:
enabled, doesn't support DPO or FUA
[ 5525.857838] sdk: sdk1
[ 5525.859468] sd 0:0:1:1088045124: [sdk] Attached SCSI disk
[ 5525.865073] sd 0:0:1:1088045124: alua: transition timeout set to 60 seconds
[ 5525.865078] sd 0:0:1:1088045124: alua: port group 00 state A preferred
supports tolusnA
[ 5526.015070] sd 0:0:1:1088045124: alua: port group 00 state A preferred
supports tolusnA
[ 5526.015213] sd 0:0:1:1088045124: alua: port group 00 state A preferred
supports tolusnA
[ 5526.587439] scsi_alloc_sdev: Allocation failure during SCSI scanning, some
SCSI devices might not be configured
[ 5526.588562] scsi_alloc_sdev: Allocation failure during SCSI scanning, some
SCSI devices might not be configured
Looking at the code of scsi_alloc_sdev(), and all the calling contexts,
there seems to be no reason to use GFP_ATMOIC here. All the different
call-contexts use a mutex at some point, and nothing in between that
requires no sleeping, as far as I could see. Additionally, the code that
allocates the block queue for the device later (scsi_mq_alloc_queue())
already uses GFP_KERNEL.
So replace it, and give the allocation a bit of a better chance to succeed,
with more ways of reclaim.
Signed-off-by: Benjamin Block <bbl...@linux.ibm.com>
---
drivers/scsi/scsi_scan.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index dd0d516f65e2..e49e6099b852 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -220,7 +220,7 @@ static struct scsi_device *scsi_alloc_sdev(struct
scsi_target *starget,
struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
sdev = kzalloc(sizeof(*sdev) + shost->transportt->device_size,
- GFP_ATOMIC);
+ GFP_KERNEL);
if (!sdev)
goto out;
--
2.20.1
