Carlo Wood wrote:
The dmesg output of 33480a0ede8dcc7e6483054279008f972bd56fd3 (thus
"before") is:
[...]
And the dmesg output of 551c012d7eea3dc5ec063c7ff9c718d39e77634f (thus
"after") is:
[...]
Your disk configurations are quite radically different between the two
kernels (see attached diff for key highlights).
The new behavior of the more recent kernel (551c012d7...) is that it now
fully drives your hardware :) The reset problems go away, NCQ is
enabled, and if you had 3.0Gbps drives (you don't) they would be driven
at a faster speed.
Given that some drives might be better tuned for benchmarks in
non-queued mode, and that a major behavior difference is that your
drives are now NCQ-enabled, the first thing I would suggest you try is
disabling NCQ:
http://linux-ata.org/faq.html#ncq
Other indicators are the other changes in the "ahci 0000:00:1f.2:
flags:" line, which do affect other behaviors, though none so important
to RAID5 performance as NCQ, I would think.
Turning on NCQ also potentially affects barrier behavior in RAID, though
I'm guessing that is not a factor here.
Jeff
-ahci 0000:00:1f.2: AHCI 0001.0100 32 slots 6 ports ? Gbps 0x3f impl SATA mode
-ahci 0000:00:1f.2: flags: 64bit ilck stag led pmp pio
+ahci 0000:00:1f.2: AHCI 0001.0100 32 slots 6 ports 3 Gbps 0x3f impl SATA mode
+ahci 0000:00:1f.2: flags: 64bit ncq ilck stag pm led clo pmp pio slum part
scsi0 : ahci
-ata1: softreset failed (port busy but CLO unavailable)
-ata1: softreset failed, retrying in 5 secs
ata1: SATA link up 1.5 Gbps (SStatus 113 SControl 300)
-ata1.00: ATA-7, max UDMA/133, 145226112 sectors: LBA48 NCQ (depth 0/32)
+ata1.00: ATA-7, max UDMA/133, 145226112 sectors: LBA48 NCQ (depth 31/32)
ata1.00: ata1: dev 0 multi count 0
ata1.00: configured for UDMA/133
scsi1 : ahci
-ata2: softreset failed (port busy but CLO unavailable)
-ata2: softreset failed, retrying in 5 secs
ata2: SATA link up 1.5 Gbps (SStatus 113 SControl 300)
-ata2.00: ATA-7, max UDMA/133, 145226112 sectors: LBA48 NCQ (depth 0/32)
+ata2.00: ATA-7, max UDMA/133, 145226112 sectors: LBA48 NCQ (depth 31/32)
ata2.00: ata2: dev 0 multi count 0
ata2.00: configured for UDMA/133
scsi2 : ahci
ata3: SATA link up 1.5 Gbps (SStatus 113 SControl 300)
-ata3.00: ATA-7, max UDMA/133, 145226112 sectors: LBA48 NCQ (depth 0/32)
+ata3.00: ATA-7, max UDMA/133, 145226112 sectors: LBA48 NCQ (depth 31/32)
ata3.00: ata3: dev 0 multi count 0
ata3.00: configured for UDMA/133
scsi3 : ahci
ata4: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
-ata4.00: ATA-7, max UDMA/133, 625142448 sectors: LBA48 NCQ (depth 0/32)
+ata4.00: ATA-7, max UDMA/133, 625142448 sectors: LBA48 NCQ (depth 31/32)
ata4.00: configured for UDMA/133
scsi4 : ahci
ata5: SATA link up 1.5 Gbps (SStatus 113 SControl 300)
