Re: [PATCH 0/3] mdraid sb and bitmap write alignment on 512e drives

2020-11-03 Thread Xiao Ni
On 11/03/2020 02:59 AM, Chris Unkel wrote: Hi Xiao, That particular array is super1.2. The block trace was captured on the disk underlying the partition device on which the md array member resides, not on the partition device itself. The partition starts 2048 sectors into the disk (1MB). S

Re: [PATCH 0/3] mdraid sb and bitmap write alignment on 512e drives

2020-11-02 Thread Chris Unkel
Hi Xiao, That particular array is super1.2. The block trace was captured on the disk underlying the partition device on which the md array member resides, not on the partition device itself. The partition starts 2048 sectors into the disk (1MB). So the 2048 sectors offset to the beginning of th

Re: [PATCH 0/3] mdraid sb and bitmap write alignment on 512e drives

2020-11-01 Thread Xiao Ni
On 10/23/2020 11:31 AM, Christopher Unkel wrote: Hello all, While investigating some performance issues on mdraid 10 volumes formed with "512e" disks (4k native/physical sector size but with 512 byte sector emulation), I've found two cases where mdraid will needlessly issue writes that start

Re: [PATCH 0/3] mdraid sb and bitmap write alignment on 512e drives

2020-10-23 Thread Chris Unkel
I don't offhand, but point well taken. I suspect that showing a difference in a benchmark is dependent on finding one where the metadata has been evicted from the drive cache. Let me think about it a bit. Thanks, --Chris On Thu, Oct 22, 2020 at 10:42 PM Song Liu wrote: > > On Thu, Oct 22,

Re: [PATCH 0/3] mdraid sb and bitmap write alignment on 512e drives

2020-10-22 Thread Song Liu
On Thu, Oct 22, 2020 at 8:31 PM Christopher Unkel wrote: > > Hello all, > > While investigating some performance issues on mdraid 10 volumes > formed with "512e" disks (4k native/physical sector size but with 512 > byte sector emulation), I've found two cases where mdraid will > needlessly issue w

[PATCH 0/3] mdraid sb and bitmap write alignment on 512e drives

2020-10-22 Thread Christopher Unkel
Hello all, While investigating some performance issues on mdraid 10 volumes formed with "512e" disks (4k native/physical sector size but with 512 byte sector emulation), I've found two cases where mdraid will needlessly issue writes that start on 4k byte boundary, but are are shorter than 4k: 1.