On 2022/08/12 10:17, John Garry wrote: > On 12/08/2022 16:41, Damien Le Moal wrote: >>>> we noticed the commit is already in mainline now, and in our tests, there is >>>> still similar regression and also on other platforms. >>>> could you guide us how to check "which host driver is being used for this >>>> test"? hope to supply some useful information. >>>> >>> For me, a complete kernel log may help. >> I had a look yesterday with my test rig. I did not see any difference in the >> default max_sectors_kb values for various drives between 5.18 and 5.19 (current >> linus tree). The test machine has 2 AHCI adapters: Intel and Marvell. Both use >> the regular AHCI driver. I have another rig with different ATA adapters but it >> is powered down and I am traveling... So cannot test that right now. >> > > FWIW, on QEMU I get a difference for IDE disk for ata_piix host. > > Interestingly ata dev max_sectors kb also gets capped from 32MB (LBA48) > -> 256KB due to swiotlb max mapping size. (It would be capped by shost > default max sectors 512KB without that swiotlb limit). I assume capping > due to swiotlb limit is not occuring on Oliver's machine. Yes, I was suspecting that we may be seeing a difference for anything that is not AHCI, e.g. with other drivers. But that seems to be the correct thing to do, no ? How was this working before without applying the swiotlb limit ? > > thanks, > John > > [ 1.497233] ata7: found unknown device (class 0) > [ 1.498341] ata7.00: ATA-7: QEMU HARDDISK, 2.5+, max UDMA/100 > [ 1.499030] ata7.00: 209716 sectors, multi 16: LBA48 > [ 1.623795] ata2: SATA link down (SStatus 0 SControl 300) > [ 1.624633] ata1: SATA link down (SStatus 0 SControl 300) > [ 1.633395] ata6: SATA link down (SStatus 0 SControl 300) > [ 1.634200] ata5: SATA link down (SStatus 0 SControl 300) > [ 1.635094] ata4: SATA link down (SStatus 0 SControl 300) > [ 1.635887] ata3: SATA link down (SStatus 0 SControl 300) > [ 1.636748] scsi 6:0:0:0: Direct-Access ATA QEMU HARDDISK > 2.5+ PQ: 0 ANSI: 5 > [ 1.641298] sd 6:0:0:0: [sda] 209716 512-byte logical blocks: (107 > MB/102 MiB) > [ 1.642188] sd 6:0:0:0: [sda] Write Protect is off > [ 1.642770] sd 6:0:0:0: [sda] Mode Sense: 00 3a 00 00 > [ 1.642783] sd 6:0:0:0: [sda] Write cache: enabled, read cache: > enabled, doesn't support DPO or FUA > [ 1.644149] sd 6:0:0:0: [sda] Preferred minimum I/O size 512 bytes > [ 1.645142] sd 6:0:0:0: Attached scsi generic sg0 type 0 > [ 1.655145] sd 6:0:0:0: [sda] Attached SCSI disk -- Damien Le Moal Western Digital Research