Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1162907 > unrolled thread

Re: [PATCH v4 01/11] block: make generic_make_request handle arbitrarily sized bios

Started byMing Lin <mlin@kernel.org>
First post2015-06-10 23:30 +0200
Last post2015-06-18 07:30 +0200
Articles 4 — 2 participants

Back to article view | Back to linux.kernel

This discussion starts older than the indexed window; earlier articles aren't shown. The article labeled Started by below is the oldest one visible, not the original post.


Contents

  Re: [PATCH v4 01/11] block: make generic_make_request handle  arbitrarily sized bios Ming Lin <mlin@kernel.org> - 2015-06-10 23:30 +0200
    Re: [PATCH v4 01/11] block: make generic_make_request handle  arbitrarily sized bios Mike Snitzer <snitzer@redhat.com> - 2015-06-10 23:50 +0200
      Re: [PATCH v4 01/11] block: make generic_make_request handle  arbitrarily sized bios Ming Lin <mlin@kernel.org> - 2015-06-11 00:10 +0200
      Re: [PATCH v4 01/11] block: make generic_make_request handle  arbitrarily sized bios Ming Lin <mlin@kernel.org> - 2015-06-18 07:30 +0200

#1162907 — Re: [PATCH v4 01/11] block: make generic_make_request handle arbitrarily sized bios

FromMing Lin <mlin@kernel.org>
Date2015-06-10 23:30 +0200
SubjectRe: [PATCH v4 01/11] block: make generic_make_request handle arbitrarily sized bios
Message-ID<pzVJn-1HN-7@gated-at.bofh.it>
On Mon, Jun 8, 2015 at 11:09 PM, Ming Lin <mlin@kernel.org> wrote:
> On Thu, 2015-06-04 at 17:06 -0400, Mike Snitzer wrote:
>> We need to test on large HW raid setups like a Netapp filer (or even
>> local SAS drives connected via some SAS controller).  Like a 8+2 drive
>> RAID6 or 8+1 RAID5 setup.  Testing with MD raid on JBOD setups with 8
>> devices is also useful.  It is larger RAID setups that will be more
>> sensitive to IO sizes being properly aligned on RAID stripe and/or chunk
>> size boundaries.
>
> Here are tests results of xfs/ext4/btrfs read/write on HW RAID6/MD RAID6/DM stripe target.
> Each case run 0.5 hour, so it took 36 hours to finish all the tests on 4.1-rc4 and 4.1-rc4-patched kernels.
>
> No performance regressions were introduced.
>
> Test server: Dell R730xd(2 sockets/48 logical cpus/264G memory)
> HW RAID6/MD RAID6/DM stripe target were configured with 10 HDDs, each 280G
> Stripe size 64k and 128k were tested.
>
> devs="/dev/sdb /dev/sdc /dev/sdd /dev/sde /dev/sdf /dev/sdg /dev/sdh /dev/sdi /dev/sdj /dev/sdk"
> spare_devs="/dev/sdl /dev/sdm"
> stripe_size=64 (or 128)
>
> MD RAID6 was created by:
> mdadm --create --verbose /dev/md0 --level=6 --raid-devices=10 $devs --spare-devices=2 $spare_devs -c $stripe_size
>
> DM stripe target was created by:
> pvcreate $devs
> vgcreate striped_vol_group $devs
> lvcreate -i10 -I${stripe_size} -L2T -nstriped_logical_volume striped_vol_group
>
> Here is an example of fio script for stripe size 128k:
> [global]
> ioengine=libaio
> iodepth=64
> direct=1
> runtime=1800
> time_based
> group_reporting
> numjobs=48
> gtod_reduce=0
> norandommap
> write_iops_log=fs
>
> [job1]
> bs=1280K
> directory=/mnt
> size=5G
> rw=read
>
> All results here: http://minggr.net/pub/20150608/fio_results/
>
> Results summary:
>
> 1. HW RAID6: stripe size 64k
>                 4.1-rc4         4.1-rc4-patched
>                 -------         ---------------
>                 (MB/s)          (MB/s)
> xfs read:       821.23          812.20  -1.09%
> xfs write:      753.16          754.42  +0.16%
> ext4 read:      827.80          834.82  +0.84%
> ext4 write:     783.08          777.58  -0.70%
> btrfs read:     859.26          871.68  +1.44%
> btrfs write:    815.63          844.40  +3.52%
>
> 2. HW RAID6: stripe size 128k
>                 4.1-rc4         4.1-rc4-patched
>                 -------         ---------------
>                 (MB/s)          (MB/s)
> xfs read:       948.27          979.11  +3.25%
> xfs write:      820.78          819.94  -0.10%
> ext4 read:      978.35          997.92  +2.00%
> ext4 write:     853.51          847.97  -0.64%
> btrfs read:     1013.1          1015.6  +0.24%
> btrfs write:    854.43          850.42  -0.46%
>
> 3. MD RAID6: stripe size 64k
>                 4.1-rc4         4.1-rc4-patched
>                 -------         ---------------
>                 (MB/s)          (MB/s)
> xfs read:       847.34          869.43  +2.60%
> xfs write:      198.67          199.03  +0.18%
> ext4 read:      763.89          767.79  +0.51%
> ext4 write:     281.44          282.83  +0.49%
> btrfs read:     756.02          743.69  -1.63%
> btrfs write:    268.37          265.93  -0.90%
>
> 4. MD RAID6: stripe size 128k
>                 4.1-rc4         4.1-rc4-patched
>                 -------         ---------------
>                 (MB/s)          (MB/s)
> xfs read:       993.04          1014.1  +2.12%
> xfs write:      293.06          298.95  +2.00%
> ext4 read:      1019.6          1020.9  +0.12%
> ext4 write:     371.51          371.47  -0.01%
> btrfs read:     1000.4          1020.8  +2.03%
> btrfs write:    241.08          246.77  +2.36%
>
> 5. DM: stripe size 64k
>                 4.1-rc4         4.1-rc4-patched
>                 -------         ---------------
>                 (MB/s)          (MB/s)
> xfs read:       1084.4          1080.1  -0.39%
> xfs write:      1071.1          1063.4  -0.71%
> ext4 read:      991.54          1003.7  +1.22%
> ext4 write:     1069.7          1052.2  -1.63%
> btrfs read:     1076.1          1082.1  +0.55%
> btrfs write:    968.98          965.07  -0.40%
>
> 6. DM: stripe size 128k
>                 4.1-rc4         4.1-rc4-patched
>                 -------         ---------------
>                 (MB/s)          (MB/s)
> xfs read:       1020.4          1066.1  +4.47%
> xfs write:      1058.2          1066.6  +0.79%
> ext4 read:      990.72          988.19  -0.25%
> ext4 write:     1050.4          1070.2  +1.88%
> btrfs read:     1080.9          1074.7  -0.57%
> btrfs write:    975.10          972.76  -0.23%

Hi Mike,

How about these numbers?

I'm also happy to run other fio jobs your team used.

Thanks.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[toc] | [next] | [standalone]


#1162909

FromMike Snitzer <snitzer@redhat.com>
Date2015-06-10 23:50 +0200
Message-ID<pzW2K-24N-23@gated-at.bofh.it>
In reply to#1162907
On Wed, Jun 10 2015 at  5:20pm -0400,
Ming Lin <mlin@kernel.org> wrote:

> On Mon, Jun 8, 2015 at 11:09 PM, Ming Lin <mlin@kernel.org> wrote:
> > On Thu, 2015-06-04 at 17:06 -0400, Mike Snitzer wrote:
> >> We need to test on large HW raid setups like a Netapp filer (or even
> >> local SAS drives connected via some SAS controller).  Like a 8+2 drive
> >> RAID6 or 8+1 RAID5 setup.  Testing with MD raid on JBOD setups with 8
> >> devices is also useful.  It is larger RAID setups that will be more
> >> sensitive to IO sizes being properly aligned on RAID stripe and/or chunk
> >> size boundaries.
> >
> > Here are tests results of xfs/ext4/btrfs read/write on HW RAID6/MD RAID6/DM stripe target.
> > Each case run 0.5 hour, so it took 36 hours to finish all the tests on 4.1-rc4 and 4.1-rc4-patched kernels.
> >
> > No performance regressions were introduced.
> >
> > Test server: Dell R730xd(2 sockets/48 logical cpus/264G memory)
> > HW RAID6/MD RAID6/DM stripe target were configured with 10 HDDs, each 280G
> > Stripe size 64k and 128k were tested.
> >
> > devs="/dev/sdb /dev/sdc /dev/sdd /dev/sde /dev/sdf /dev/sdg /dev/sdh /dev/sdi /dev/sdj /dev/sdk"
> > spare_devs="/dev/sdl /dev/sdm"
> > stripe_size=64 (or 128)
> >
> > MD RAID6 was created by:
> > mdadm --create --verbose /dev/md0 --level=6 --raid-devices=10 $devs --spare-devices=2 $spare_devs -c $stripe_size
> >
> > DM stripe target was created by:
> > pvcreate $devs
> > vgcreate striped_vol_group $devs
> > lvcreate -i10 -I${stripe_size} -L2T -nstriped_logical_volume striped_vol_group

DM had a regression relative to merge_bvec that wasn't fixed until
recently (it wasn't in 4.1-rc4), see commit 1c220c69ce0 ("dm: fix
casting bug in dm_merge_bvec()").  It was introduced in 4.1.

So your 4.1-rc4 DM stripe testing may have effectively been with
merge_bvec disabled.

> > Here is an example of fio script for stripe size 128k:
> > [global]
> > ioengine=libaio
> > iodepth=64
> > direct=1
> > runtime=1800
> > time_based
> > group_reporting
> > numjobs=48
> > gtod_reduce=0
> > norandommap
> > write_iops_log=fs
> >
> > [job1]
> > bs=1280K
> > directory=/mnt
> > size=5G
> > rw=read
> >
> > All results here: http://minggr.net/pub/20150608/fio_results/
> >
> > Results summary:
> >
> > 1. HW RAID6: stripe size 64k
> >                 4.1-rc4         4.1-rc4-patched
> >                 -------         ---------------
> >                 (MB/s)          (MB/s)
> > xfs read:       821.23          812.20  -1.09%
> > xfs write:      753.16          754.42  +0.16%
> > ext4 read:      827.80          834.82  +0.84%
> > ext4 write:     783.08          777.58  -0.70%
> > btrfs read:     859.26          871.68  +1.44%
> > btrfs write:    815.63          844.40  +3.52%
> >
> > 2. HW RAID6: stripe size 128k
> >                 4.1-rc4         4.1-rc4-patched
> >                 -------         ---------------
> >                 (MB/s)          (MB/s)
> > xfs read:       948.27          979.11  +3.25%
> > xfs write:      820.78          819.94  -0.10%
> > ext4 read:      978.35          997.92  +2.00%
> > ext4 write:     853.51          847.97  -0.64%
> > btrfs read:     1013.1          1015.6  +0.24%
> > btrfs write:    854.43          850.42  -0.46%
> >
> > 3. MD RAID6: stripe size 64k
> >                 4.1-rc4         4.1-rc4-patched
> >                 -------         ---------------
> >                 (MB/s)          (MB/s)
> > xfs read:       847.34          869.43  +2.60%
> > xfs write:      198.67          199.03  +0.18%
> > ext4 read:      763.89          767.79  +0.51%
> > ext4 write:     281.44          282.83  +0.49%
> > btrfs read:     756.02          743.69  -1.63%
> > btrfs write:    268.37          265.93  -0.90%
> >
> > 4. MD RAID6: stripe size 128k
> >                 4.1-rc4         4.1-rc4-patched
> >                 -------         ---------------
> >                 (MB/s)          (MB/s)
> > xfs read:       993.04          1014.1  +2.12%
> > xfs write:      293.06          298.95  +2.00%
> > ext4 read:      1019.6          1020.9  +0.12%
> > ext4 write:     371.51          371.47  -0.01%
> > btrfs read:     1000.4          1020.8  +2.03%
> > btrfs write:    241.08          246.77  +2.36%
> >
> > 5. DM: stripe size 64k
> >                 4.1-rc4         4.1-rc4-patched
> >                 -------         ---------------
> >                 (MB/s)          (MB/s)
> > xfs read:       1084.4          1080.1  -0.39%
> > xfs write:      1071.1          1063.4  -0.71%
> > ext4 read:      991.54          1003.7  +1.22%
> > ext4 write:     1069.7          1052.2  -1.63%
> > btrfs read:     1076.1          1082.1  +0.55%
> > btrfs write:    968.98          965.07  -0.40%
> >
> > 6. DM: stripe size 128k
> >                 4.1-rc4         4.1-rc4-patched
> >                 -------         ---------------
> >                 (MB/s)          (MB/s)
> > xfs read:       1020.4          1066.1  +4.47%
> > xfs write:      1058.2          1066.6  +0.79%
> > ext4 read:      990.72          988.19  -0.25%
> > ext4 write:     1050.4          1070.2  +1.88%
> > btrfs read:     1080.9          1074.7  -0.57%
> > btrfs write:    975.10          972.76  -0.23%
> 
> Hi Mike,
> 
> How about these numbers?

Looks fairly good.  I just am not sure the workload is going to test the
code paths in question like we'd hope.  I'll have to set aside some time
to think through scenarios to test.

My concern still remains that at some point it the future we'll regret
not having merge_bvec but it'll be too late.  That is just my own FUD at
this point...

> I'm also happy to run other fio jobs your team used.

I've been busy getting DM changes for the 4.2 merge window finalized.
As such I haven't connected with others on the team to discuss this
issue.

I'll see if we can make time in the next 2 days.  But I also have
RHEL-specific kernel deadlines I'm coming up against.

Seems late to be staging this extensive a change for 4.2... are you
pushing for this code to land in the 4.2 merge window?  Or do we have
time to work this further and target the 4.3 merge?

Mike
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[toc] | [prev] | [next] | [standalone]


#1162912

FromMing Lin <mlin@kernel.org>
Date2015-06-11 00:10 +0200
Message-ID<pzWm7-2Hg-39@gated-at.bofh.it>
In reply to#1162909
On Wed, Jun 10, 2015 at 2:46 PM, Mike Snitzer <snitzer@redhat.com> wrote:
> On Wed, Jun 10 2015 at  5:20pm -0400,
> Ming Lin <mlin@kernel.org> wrote:
>
>> On Mon, Jun 8, 2015 at 11:09 PM, Ming Lin <mlin@kernel.org> wrote:
>> > On Thu, 2015-06-04 at 17:06 -0400, Mike Snitzer wrote:
>> >> We need to test on large HW raid setups like a Netapp filer (or even
>> >> local SAS drives connected via some SAS controller).  Like a 8+2 drive
>> >> RAID6 or 8+1 RAID5 setup.  Testing with MD raid on JBOD setups with 8
>> >> devices is also useful.  It is larger RAID setups that will be more
>> >> sensitive to IO sizes being properly aligned on RAID stripe and/or chunk
>> >> size boundaries.
>> >
>> > Here are tests results of xfs/ext4/btrfs read/write on HW RAID6/MD RAID6/DM stripe target.
>> > Each case run 0.5 hour, so it took 36 hours to finish all the tests on 4.1-rc4 and 4.1-rc4-patched kernels.
>> >
>> > No performance regressions were introduced.
>> >
>> > Test server: Dell R730xd(2 sockets/48 logical cpus/264G memory)
>> > HW RAID6/MD RAID6/DM stripe target were configured with 10 HDDs, each 280G
>> > Stripe size 64k and 128k were tested.
>> >
>> > devs="/dev/sdb /dev/sdc /dev/sdd /dev/sde /dev/sdf /dev/sdg /dev/sdh /dev/sdi /dev/sdj /dev/sdk"
>> > spare_devs="/dev/sdl /dev/sdm"
>> > stripe_size=64 (or 128)
>> >
>> > MD RAID6 was created by:
>> > mdadm --create --verbose /dev/md0 --level=6 --raid-devices=10 $devs --spare-devices=2 $spare_devs -c $stripe_size
>> >
>> > DM stripe target was created by:
>> > pvcreate $devs
>> > vgcreate striped_vol_group $devs
>> > lvcreate -i10 -I${stripe_size} -L2T -nstriped_logical_volume striped_vol_group
>
> DM had a regression relative to merge_bvec that wasn't fixed until
> recently (it wasn't in 4.1-rc4), see commit 1c220c69ce0 ("dm: fix
> casting bug in dm_merge_bvec()").  It was introduced in 4.1.
>
> So your 4.1-rc4 DM stripe testing may have effectively been with
> merge_bvec disabled.

I'l rebase it to latest Linus tree and re-run DM stripe testing.

>
>> > Here is an example of fio script for stripe size 128k:
>> > [global]
>> > ioengine=libaio
>> > iodepth=64
>> > direct=1
>> > runtime=1800
>> > time_based
>> > group_reporting
>> > numjobs=48
>> > gtod_reduce=0
>> > norandommap
>> > write_iops_log=fs
>> >
>> > [job1]
>> > bs=1280K
>> > directory=/mnt
>> > size=5G
>> > rw=read
>> >
>> > All results here: http://minggr.net/pub/20150608/fio_results/
>> >
>> > Results summary:
>> >
>> > 1. HW RAID6: stripe size 64k
>> >                 4.1-rc4         4.1-rc4-patched
>> >                 -------         ---------------
>> >                 (MB/s)          (MB/s)
>> > xfs read:       821.23          812.20  -1.09%
>> > xfs write:      753.16          754.42  +0.16%
>> > ext4 read:      827.80          834.82  +0.84%
>> > ext4 write:     783.08          777.58  -0.70%
>> > btrfs read:     859.26          871.68  +1.44%
>> > btrfs write:    815.63          844.40  +3.52%
>> >
>> > 2. HW RAID6: stripe size 128k
>> >                 4.1-rc4         4.1-rc4-patched
>> >                 -------         ---------------
>> >                 (MB/s)          (MB/s)
>> > xfs read:       948.27          979.11  +3.25%
>> > xfs write:      820.78          819.94  -0.10%
>> > ext4 read:      978.35          997.92  +2.00%
>> > ext4 write:     853.51          847.97  -0.64%
>> > btrfs read:     1013.1          1015.6  +0.24%
>> > btrfs write:    854.43          850.42  -0.46%
>> >
>> > 3. MD RAID6: stripe size 64k
>> >                 4.1-rc4         4.1-rc4-patched
>> >                 -------         ---------------
>> >                 (MB/s)          (MB/s)
>> > xfs read:       847.34          869.43  +2.60%
>> > xfs write:      198.67          199.03  +0.18%
>> > ext4 read:      763.89          767.79  +0.51%
>> > ext4 write:     281.44          282.83  +0.49%
>> > btrfs read:     756.02          743.69  -1.63%
>> > btrfs write:    268.37          265.93  -0.90%
>> >
>> > 4. MD RAID6: stripe size 128k
>> >                 4.1-rc4         4.1-rc4-patched
>> >                 -------         ---------------
>> >                 (MB/s)          (MB/s)
>> > xfs read:       993.04          1014.1  +2.12%
>> > xfs write:      293.06          298.95  +2.00%
>> > ext4 read:      1019.6          1020.9  +0.12%
>> > ext4 write:     371.51          371.47  -0.01%
>> > btrfs read:     1000.4          1020.8  +2.03%
>> > btrfs write:    241.08          246.77  +2.36%
>> >
>> > 5. DM: stripe size 64k
>> >                 4.1-rc4         4.1-rc4-patched
>> >                 -------         ---------------
>> >                 (MB/s)          (MB/s)
>> > xfs read:       1084.4          1080.1  -0.39%
>> > xfs write:      1071.1          1063.4  -0.71%
>> > ext4 read:      991.54          1003.7  +1.22%
>> > ext4 write:     1069.7          1052.2  -1.63%
>> > btrfs read:     1076.1          1082.1  +0.55%
>> > btrfs write:    968.98          965.07  -0.40%
>> >
>> > 6. DM: stripe size 128k
>> >                 4.1-rc4         4.1-rc4-patched
>> >                 -------         ---------------
>> >                 (MB/s)          (MB/s)
>> > xfs read:       1020.4          1066.1  +4.47%
>> > xfs write:      1058.2          1066.6  +0.79%
>> > ext4 read:      990.72          988.19  -0.25%
>> > ext4 write:     1050.4          1070.2  +1.88%
>> > btrfs read:     1080.9          1074.7  -0.57%
>> > btrfs write:    975.10          972.76  -0.23%
>>
>> Hi Mike,
>>
>> How about these numbers?
>
> Looks fairly good.  I just am not sure the workload is going to test the
> code paths in question like we'd hope.  I'll have to set aside some time

How about adding some counters to record, for example, how many time
->merge_bvec is called in old kernel and how many time bio splitting is called
in patched kernel?

> to think through scenarios to test.

Great.

>
> My concern still remains that at some point it the future we'll regret
> not having merge_bvec but it'll be too late.  That is just my own FUD at
> this point...
>
>> I'm also happy to run other fio jobs your team used.
>
> I've been busy getting DM changes for the 4.2 merge window finalized.
> As such I haven't connected with others on the team to discuss this
> issue.
>
> I'll see if we can make time in the next 2 days.  But I also have
> RHEL-specific kernel deadlines I'm coming up against.
>
> Seems late to be staging this extensive a change for 4.2... are you
> pushing for this code to land in the 4.2 merge window?  Or do we have
> time to work this further and target the 4.3 merge?

I'm OK to target the 4.3 merge.
But hope we can get it into linux-next tree ASAP for more wide tests.

>
> Mike
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[toc] | [prev] | [next] | [standalone]


#1167590

FromMing Lin <mlin@kernel.org>
Date2015-06-18 07:30 +0200
Message-ID<pCAyJ-7oA-1@gated-at.bofh.it>
In reply to#1162909
On Wed, Jun 10, 2015 at 2:46 PM, Mike Snitzer <snitzer@redhat.com> wrote:
> On Wed, Jun 10 2015 at  5:20pm -0400,
> Ming Lin <mlin@kernel.org> wrote:
>
>> On Mon, Jun 8, 2015 at 11:09 PM, Ming Lin <mlin@kernel.org> wrote:
>> > On Thu, 2015-06-04 at 17:06 -0400, Mike Snitzer wrote:
>> >> We need to test on large HW raid setups like a Netapp filer (or even
>> >> local SAS drives connected via some SAS controller).  Like a 8+2 drive
>> >> RAID6 or 8+1 RAID5 setup.  Testing with MD raid on JBOD setups with 8
>> >> devices is also useful.  It is larger RAID setups that will be more
>> >> sensitive to IO sizes being properly aligned on RAID stripe and/or chunk
>> >> size boundaries.
>> >
>> > Here are tests results of xfs/ext4/btrfs read/write on HW RAID6/MD RAID6/DM stripe target.
>> > Each case run 0.5 hour, so it took 36 hours to finish all the tests on 4.1-rc4 and 4.1-rc4-patched kernels.
>> >
>> > No performance regressions were introduced.
>> >
>> > Test server: Dell R730xd(2 sockets/48 logical cpus/264G memory)
>> > HW RAID6/MD RAID6/DM stripe target were configured with 10 HDDs, each 280G
>> > Stripe size 64k and 128k were tested.
>> >
>> > devs="/dev/sdb /dev/sdc /dev/sdd /dev/sde /dev/sdf /dev/sdg /dev/sdh /dev/sdi /dev/sdj /dev/sdk"
>> > spare_devs="/dev/sdl /dev/sdm"
>> > stripe_size=64 (or 128)
>> >
>> > MD RAID6 was created by:
>> > mdadm --create --verbose /dev/md0 --level=6 --raid-devices=10 $devs --spare-devices=2 $spare_devs -c $stripe_size
>> >
>> > DM stripe target was created by:
>> > pvcreate $devs
>> > vgcreate striped_vol_group $devs
>> > lvcreate -i10 -I${stripe_size} -L2T -nstriped_logical_volume striped_vol_group
>
> DM had a regression relative to merge_bvec that wasn't fixed until
> recently (it wasn't in 4.1-rc4), see commit 1c220c69ce0 ("dm: fix
> casting bug in dm_merge_bvec()").  It was introduced in 4.1.
>
> So your 4.1-rc4 DM stripe testing may have effectively been with
> merge_bvec disabled.
>
>> > Here is an example of fio script for stripe size 128k:
>> > [global]
>> > ioengine=libaio
>> > iodepth=64
>> > direct=1
>> > runtime=1800
>> > time_based
>> > group_reporting
>> > numjobs=48
>> > gtod_reduce=0
>> > norandommap
>> > write_iops_log=fs
>> >
>> > [job1]
>> > bs=1280K
>> > directory=/mnt
>> > size=5G
>> > rw=read
>> >
>> > All results here: http://minggr.net/pub/20150608/fio_results/
>> >
>> > Results summary:
>> >
>> > 1. HW RAID6: stripe size 64k
>> >                 4.1-rc4         4.1-rc4-patched
>> >                 -------         ---------------
>> >                 (MB/s)          (MB/s)
>> > xfs read:       821.23          812.20  -1.09%
>> > xfs write:      753.16          754.42  +0.16%
>> > ext4 read:      827.80          834.82  +0.84%
>> > ext4 write:     783.08          777.58  -0.70%
>> > btrfs read:     859.26          871.68  +1.44%
>> > btrfs write:    815.63          844.40  +3.52%
>> >
>> > 2. HW RAID6: stripe size 128k
>> >                 4.1-rc4         4.1-rc4-patched
>> >                 -------         ---------------
>> >                 (MB/s)          (MB/s)
>> > xfs read:       948.27          979.11  +3.25%
>> > xfs write:      820.78          819.94  -0.10%
>> > ext4 read:      978.35          997.92  +2.00%
>> > ext4 write:     853.51          847.97  -0.64%
>> > btrfs read:     1013.1          1015.6  +0.24%
>> > btrfs write:    854.43          850.42  -0.46%
>> >
>> > 3. MD RAID6: stripe size 64k
>> >                 4.1-rc4         4.1-rc4-patched
>> >                 -------         ---------------
>> >                 (MB/s)          (MB/s)
>> > xfs read:       847.34          869.43  +2.60%
>> > xfs write:      198.67          199.03  +0.18%
>> > ext4 read:      763.89          767.79  +0.51%
>> > ext4 write:     281.44          282.83  +0.49%
>> > btrfs read:     756.02          743.69  -1.63%
>> > btrfs write:    268.37          265.93  -0.90%
>> >
>> > 4. MD RAID6: stripe size 128k
>> >                 4.1-rc4         4.1-rc4-patched
>> >                 -------         ---------------
>> >                 (MB/s)          (MB/s)
>> > xfs read:       993.04          1014.1  +2.12%
>> > xfs write:      293.06          298.95  +2.00%
>> > ext4 read:      1019.6          1020.9  +0.12%
>> > ext4 write:     371.51          371.47  -0.01%
>> > btrfs read:     1000.4          1020.8  +2.03%
>> > btrfs write:    241.08          246.77  +2.36%
>> >
>> > 5. DM: stripe size 64k
>> >                 4.1-rc4         4.1-rc4-patched
>> >                 -------         ---------------
>> >                 (MB/s)          (MB/s)
>> > xfs read:       1084.4          1080.1  -0.39%
>> > xfs write:      1071.1          1063.4  -0.71%
>> > ext4 read:      991.54          1003.7  +1.22%
>> > ext4 write:     1069.7          1052.2  -1.63%
>> > btrfs read:     1076.1          1082.1  +0.55%
>> > btrfs write:    968.98          965.07  -0.40%
>> >
>> > 6. DM: stripe size 128k
>> >                 4.1-rc4         4.1-rc4-patched
>> >                 -------         ---------------
>> >                 (MB/s)          (MB/s)
>> > xfs read:       1020.4          1066.1  +4.47%
>> > xfs write:      1058.2          1066.6  +0.79%
>> > ext4 read:      990.72          988.19  -0.25%
>> > ext4 write:     1050.4          1070.2  +1.88%
>> > btrfs read:     1080.9          1074.7  -0.57%
>> > btrfs write:    975.10          972.76  -0.23%
>>
>> Hi Mike,
>>
>> How about these numbers?
>
> Looks fairly good.  I just am not sure the workload is going to test the
> code paths in question like we'd hope.  I'll have to set aside some time
> to think through scenarios to test.

Hi Mike,

Will you get a chance to think about it?

Thanks.

>
> My concern still remains that at some point it the future we'll regret
> not having merge_bvec but it'll be too late.  That is just my own FUD at
> this point...
>
>> I'm also happy to run other fio jobs your team used.
>
> I've been busy getting DM changes for the 4.2 merge window finalized.
> As such I haven't connected with others on the team to discuss this
> issue.
>
> I'll see if we can make time in the next 2 days.  But I also have
> RHEL-specific kernel deadlines I'm coming up against.
>
> Seems late to be staging this extensive a change for 4.2... are you
> pushing for this code to land in the 4.2 merge window?  Or do we have
> time to work this further and target the 4.3 merge?
>
> Mike
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[toc] | [prev] | [standalone]


Back to top | Article view | linux.kernel


csiph-web