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

2015-06-17 Thread Ming Lin
On Wed, Jun 10, 2015 at 2:46 PM, Mike Snitzer wrote: > On Wed, Jun 10 2015 at 5:20pm -0400, > Ming Lin wrote: > >> On Mon, Jun 8, 2015 at 11:09 PM, Ming Lin 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

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

2015-06-17 Thread Ming Lin
On Wed, Jun 10, 2015 at 2:46 PM, Mike Snitzer snit...@redhat.com wrote: On Wed, Jun 10 2015 at 5:20pm -0400, Ming Lin m...@kernel.org wrote: On Mon, Jun 8, 2015 at 11:09 PM, Ming Lin m...@kernel.org wrote: On Thu, 2015-06-04 at 17:06 -0400, Mike Snitzer wrote: We need to test on large HW

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

2015-06-11 Thread Ming Lin
On Wed, 2015-06-10 at 15:06 -0700, Ming Lin wrote: > On Wed, Jun 10, 2015 at 2:46 PM, Mike Snitzer wrote: > > On Wed, Jun 10 2015 at 5:20pm -0400, > > Ming Lin wrote: > > > >> On Mon, Jun 8, 2015 at 11:09 PM, Ming Lin wrote: > >> > On Thu, 2015-06-04 at 17:06 -0400, Mike Snitzer wrote: > >> >>

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

2015-06-11 Thread Ming Lin
On Wed, 2015-06-10 at 15:06 -0700, Ming Lin wrote: On Wed, Jun 10, 2015 at 2:46 PM, Mike Snitzer snit...@redhat.com wrote: On Wed, Jun 10 2015 at 5:20pm -0400, Ming Lin m...@kernel.org wrote: On Mon, Jun 8, 2015 at 11:09 PM, Ming Lin m...@kernel.org wrote: On Thu, 2015-06-04 at 17:06

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

2015-06-10 Thread Ming Lin
On Wed, Jun 10, 2015 at 2:46 PM, Mike Snitzer wrote: > On Wed, Jun 10 2015 at 5:20pm -0400, > Ming Lin wrote: > >> On Mon, Jun 8, 2015 at 11:09 PM, Ming Lin 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

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

2015-06-10 Thread Mike Snitzer
On Wed, Jun 10 2015 at 5:20pm -0400, Ming Lin wrote: > On Mon, Jun 8, 2015 at 11:09 PM, Ming Lin 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).

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

2015-06-10 Thread Ming Lin
On Mon, Jun 8, 2015 at 11:09 PM, Ming Lin 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

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

2015-06-10 Thread Ming Lin
On Mon, Jun 8, 2015 at 11:09 PM, Ming Lin m...@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

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

2015-06-10 Thread Mike Snitzer
On Wed, Jun 10 2015 at 5:20pm -0400, Ming Lin m...@kernel.org wrote: On Mon, Jun 8, 2015 at 11:09 PM, Ming Lin m...@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

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

2015-06-10 Thread Ming Lin
On Wed, Jun 10, 2015 at 2:46 PM, Mike Snitzer snit...@redhat.com wrote: On Wed, Jun 10 2015 at 5:20pm -0400, Ming Lin m...@kernel.org wrote: On Mon, Jun 8, 2015 at 11:09 PM, Ming Lin m...@kernel.org wrote: On Thu, 2015-06-04 at 17:06 -0400, Mike Snitzer wrote: We need to test on large HW

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

2015-06-09 Thread Ming Lin
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.

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

2015-06-09 Thread Ming Lin
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

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

2015-06-04 Thread Ming Lin
On Thu, Jun 4, 2015 at 5:06 PM, Mike Snitzer wrote: > On Thu, Jun 04 2015 at 6:21pm -0400, > Ming Lin wrote: > >> On Thu, Jun 4, 2015 at 2:06 PM, 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

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

2015-06-04 Thread Mike Snitzer
On Thu, Jun 04 2015 at 6:21pm -0400, Ming Lin wrote: > On Thu, Jun 4, 2015 at 2:06 PM, 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.

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

2015-06-04 Thread Ming Lin
On Thu, Jun 4, 2015 at 2:06 PM, Mike Snitzer wrote: > On Tue, Jun 02 2015 at 4:59pm -0400, > Ming Lin wrote: > >> On Sun, May 31, 2015 at 11:02 PM, Ming Lin wrote: >> > On Thu, 2015-05-28 at 01:36 +0100, Alasdair G Kergon wrote: >> >> On Wed, May 27, 2015 at 04:42:44PM -0700, Ming Lin wrote:

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

2015-06-04 Thread Mike Snitzer
On Tue, Jun 02 2015 at 4:59pm -0400, Ming Lin wrote: > On Sun, May 31, 2015 at 11:02 PM, Ming Lin wrote: > > On Thu, 2015-05-28 at 01:36 +0100, Alasdair G Kergon wrote: > >> On Wed, May 27, 2015 at 04:42:44PM -0700, Ming Lin wrote: > >> > Here are fio results of XFS on a DM stripped target

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

2015-06-04 Thread Ming Lin
On Thu, Jun 4, 2015 at 5:06 PM, Mike Snitzer snit...@redhat.com wrote: On Thu, Jun 04 2015 at 6:21pm -0400, Ming Lin m...@kernel.org wrote: On Thu, Jun 4, 2015 at 2:06 PM, Mike Snitzer snit...@redhat.com wrote: We need to test on large HW raid setups like a Netapp filer (or even local

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

2015-06-04 Thread Mike Snitzer
On Tue, Jun 02 2015 at 4:59pm -0400, Ming Lin m...@kernel.org wrote: On Sun, May 31, 2015 at 11:02 PM, Ming Lin m...@kernel.org wrote: On Thu, 2015-05-28 at 01:36 +0100, Alasdair G Kergon wrote: On Wed, May 27, 2015 at 04:42:44PM -0700, Ming Lin wrote: Here are fio results of XFS on a DM

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

2015-06-04 Thread Mike Snitzer
On Thu, Jun 04 2015 at 6:21pm -0400, Ming Lin m...@kernel.org wrote: On Thu, Jun 4, 2015 at 2:06 PM, Mike Snitzer snit...@redhat.com 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

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

2015-06-04 Thread Ming Lin
On Thu, Jun 4, 2015 at 2:06 PM, Mike Snitzer snit...@redhat.com wrote: On Tue, Jun 02 2015 at 4:59pm -0400, Ming Lin m...@kernel.org wrote: On Sun, May 31, 2015 at 11:02 PM, Ming Lin m...@kernel.org wrote: On Thu, 2015-05-28 at 01:36 +0100, Alasdair G Kergon wrote: On Wed, May 27, 2015 at

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

2015-06-02 Thread NeilBrown
On Tue, 26 May 2015 16:34:14 +0100 Alasdair G Kergon wrote: > On Tue, May 26, 2015 at 08:02:08AM -0700, Ming Lin wrote: > > Now bio_add_page() can build lager bios. > > And blk_queue_split() can split the bios in ->make_request() if needed. > > But why not try to make the bio the right size in

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

2015-06-02 Thread Ming Lin
On Sun, May 31, 2015 at 11:02 PM, Ming Lin wrote: > On Thu, 2015-05-28 at 01:36 +0100, Alasdair G Kergon wrote: >> On Wed, May 27, 2015 at 04:42:44PM -0700, Ming Lin wrote: >> > Here are fio results of XFS on a DM stripped target with 2 SSDs + 1 HDD. >> > Does it make sense? >> >> To stripe

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

2015-06-02 Thread Ming Lin
On Sun, May 31, 2015 at 11:02 PM, Ming Lin m...@kernel.org wrote: On Thu, 2015-05-28 at 01:36 +0100, Alasdair G Kergon wrote: On Wed, May 27, 2015 at 04:42:44PM -0700, Ming Lin wrote: Here are fio results of XFS on a DM stripped target with 2 SSDs + 1 HDD. Does it make sense? To stripe

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

2015-06-02 Thread NeilBrown
On Tue, 26 May 2015 16:34:14 +0100 Alasdair G Kergon a...@redhat.com wrote: On Tue, May 26, 2015 at 08:02:08AM -0700, Ming Lin wrote: Now bio_add_page() can build lager bios. And blk_queue_split() can split the bios in -make_request() if needed. But why not try to make the bio the right

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

2015-06-01 Thread Ming Lin
On Thu, 2015-05-28 at 01:36 +0100, Alasdair G Kergon wrote: > On Wed, May 27, 2015 at 04:42:44PM -0700, Ming Lin wrote: > > Here are fio results of XFS on a DM stripped target with 2 SSDs + 1 HDD. > > Does it make sense? > > To stripe across devices with different characteristics? > > Some

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

2015-06-01 Thread Ming Lin
On Thu, 2015-05-28 at 01:36 +0100, Alasdair G Kergon wrote: On Wed, May 27, 2015 at 04:42:44PM -0700, Ming Lin wrote: Here are fio results of XFS on a DM stripped target with 2 SSDs + 1 HDD. Does it make sense? To stripe across devices with different characteristics? Some suggestions.

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

2015-05-29 Thread Mike Snitzer
On Fri, May 29 2015 at 3:05P -0400, Ming Lin wrote: > On Wed, May 27, 2015 at 5:36 PM, Alasdair G Kergon wrote: > > On Wed, May 27, 2015 at 04:42:44PM -0700, Ming Lin wrote: > >> Here are fio results of XFS on a DM stripped target with 2 SSDs + 1 HDD. > >> Does it make sense? > > > > To stripe

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

2015-05-29 Thread Ming Lin
On Wed, May 27, 2015 at 5:36 PM, Alasdair G Kergon wrote: > On Wed, May 27, 2015 at 04:42:44PM -0700, Ming Lin wrote: >> Here are fio results of XFS on a DM stripped target with 2 SSDs + 1 HDD. >> Does it make sense? > > To stripe across devices with different characteristics? > > Some

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

2015-05-29 Thread Ming Lin
On Wed, May 27, 2015 at 5:36 PM, Alasdair G Kergon a...@redhat.com wrote: On Wed, May 27, 2015 at 04:42:44PM -0700, Ming Lin wrote: Here are fio results of XFS on a DM stripped target with 2 SSDs + 1 HDD. Does it make sense? To stripe across devices with different characteristics? Some

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

2015-05-29 Thread Mike Snitzer
On Fri, May 29 2015 at 3:05P -0400, Ming Lin m...@kernel.org wrote: On Wed, May 27, 2015 at 5:36 PM, Alasdair G Kergon a...@redhat.com wrote: On Wed, May 27, 2015 at 04:42:44PM -0700, Ming Lin wrote: Here are fio results of XFS on a DM stripped target with 2 SSDs + 1 HDD. Does it make

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

2015-05-27 Thread Ming Lin
On Wed, May 27, 2015 at 5:36 PM, Alasdair G Kergon wrote: > On Wed, May 27, 2015 at 04:42:44PM -0700, Ming Lin wrote: >> Here are fio results of XFS on a DM stripped target with 2 SSDs + 1 HDD. >> Does it make sense? > > To stripe across devices with different characteristics? I intended to test

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

2015-05-27 Thread Alasdair G Kergon
On Wed, May 27, 2015 at 04:42:44PM -0700, Ming Lin wrote: > Here are fio results of XFS on a DM stripped target with 2 SSDs + 1 HDD. > Does it make sense? To stripe across devices with different characteristics? Some suggestions. Prepare 3 kernels. O - Old kernel. M - Old kernel with

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

2015-05-27 Thread Ming Lin
On Tue, May 26, 2015 at 9:04 AM, Mike Snitzer wrote: > On Tue, May 26 2015 at 11:02am -0400, > Ming Lin wrote: > >> On Tue, May 26, 2015 at 7:36 AM, Mike Snitzer wrote: >> > On Fri, May 22 2015 at 2:18pm -0400, >> > Ming Lin wrote: >> > >> >> From: Kent Overstreet >> >> >> >> The way the

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

2015-05-27 Thread Christoph Hellwig
On Wed, May 27, 2015 at 01:40:22AM +0100, Alasdair G Kergon wrote: > It does sometimes make a significant difference to device-mapper stacks. > DM only uses it for performance reasons - it can already split bios when > it needs to. I tried to remove merge_bvec_fn from DM several years ago but >

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

2015-05-27 Thread Christoph Hellwig
On Wed, May 27, 2015 at 01:40:22AM +0100, Alasdair G Kergon wrote: It does sometimes make a significant difference to device-mapper stacks. DM only uses it for performance reasons - it can already split bios when it needs to. I tried to remove merge_bvec_fn from DM several years ago but

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

2015-05-27 Thread Ming Lin
On Tue, May 26, 2015 at 9:04 AM, Mike Snitzer snit...@redhat.com wrote: On Tue, May 26 2015 at 11:02am -0400, Ming Lin m...@kernel.org wrote: On Tue, May 26, 2015 at 7:36 AM, Mike Snitzer snit...@redhat.com wrote: On Fri, May 22 2015 at 2:18pm -0400, Ming Lin m...@kernel.org wrote:

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

2015-05-27 Thread Alasdair G Kergon
On Wed, May 27, 2015 at 04:42:44PM -0700, Ming Lin wrote: Here are fio results of XFS on a DM stripped target with 2 SSDs + 1 HDD. Does it make sense? To stripe across devices with different characteristics? Some suggestions. Prepare 3 kernels. O - Old kernel. M - Old kernel with

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

2015-05-27 Thread Ming Lin
On Wed, May 27, 2015 at 5:36 PM, Alasdair G Kergon a...@redhat.com wrote: On Wed, May 27, 2015 at 04:42:44PM -0700, Ming Lin wrote: Here are fio results of XFS on a DM stripped target with 2 SSDs + 1 HDD. Does it make sense? To stripe across devices with different characteristics? I intended

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

2015-05-26 Thread Alasdair G Kergon
On Wed, May 27, 2015 at 09:06:40AM +1000, Neil Brown wrote: > Because we don't know what the "right" size is. And the "right" size can > change when array reconfiguration happens. In certain configurations today, device-mapper does report back a sensible maximum bio size smaller than would

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

2015-05-26 Thread NeilBrown
On Tue, 26 May 2015 16:34:14 +0100 Alasdair G Kergon wrote: > On Tue, May 26, 2015 at 08:02:08AM -0700, Ming Lin wrote: > > Now bio_add_page() can build lager bios. > > And blk_queue_split() can split the bios in ->make_request() if needed. > > But why not try to make the bio the right size in

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

2015-05-26 Thread Ming Lin
On Tue, May 26, 2015 at 9:04 AM, Mike Snitzer wrote: > On Tue, May 26 2015 at 11:02am -0400, > Ming Lin wrote: > >> On Tue, May 26, 2015 at 7:36 AM, Mike Snitzer wrote: >> > On Fri, May 22 2015 at 2:18pm -0400, >> > Ming Lin wrote: >> > >> >> From: Kent Overstreet >> >> >> >> The way the

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

2015-05-26 Thread Mike Snitzer
On Tue, May 26 2015 at 11:02am -0400, Ming Lin wrote: > On Tue, May 26, 2015 at 7:36 AM, Mike Snitzer wrote: > > On Fri, May 22 2015 at 2:18pm -0400, > > Ming Lin wrote: > > > >> From: Kent Overstreet > >> > >> The way the block layer is currently written, it goes to great lengths > >> to

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

2015-05-26 Thread Alasdair G Kergon
On Tue, May 26, 2015 at 08:02:08AM -0700, Ming Lin wrote: > Now bio_add_page() can build lager bios. > And blk_queue_split() can split the bios in ->make_request() if needed. But why not try to make the bio the right size in the first place so you don't have to incur the performance impact of

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

2015-05-26 Thread Ming Lin
On Tue, May 26, 2015 at 7:36 AM, Mike Snitzer wrote: > On Fri, May 22 2015 at 2:18pm -0400, > Ming Lin wrote: > >> From: Kent Overstreet >> >> The way the block layer is currently written, it goes to great lengths >> to avoid having to split bios; upper layer code (such as bio_add_page()) >>

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

2015-05-26 Thread Mike Snitzer
On Fri, May 22 2015 at 2:18pm -0400, Ming Lin wrote: > From: Kent Overstreet > > The way the block layer is currently written, it goes to great lengths > to avoid having to split bios; upper layer code (such as bio_add_page()) > checks what the underlying device can handle and tries to always

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

2015-05-26 Thread Alasdair G Kergon
On Wed, May 27, 2015 at 09:06:40AM +1000, Neil Brown wrote: Because we don't know what the right size is. And the right size can change when array reconfiguration happens. In certain configurations today, device-mapper does report back a sensible maximum bio size smaller than would otherwise

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

2015-05-26 Thread Alasdair G Kergon
On Tue, May 26, 2015 at 08:02:08AM -0700, Ming Lin wrote: Now bio_add_page() can build lager bios. And blk_queue_split() can split the bios in -make_request() if needed. But why not try to make the bio the right size in the first place so you don't have to incur the performance impact of

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

2015-05-26 Thread Ming Lin
On Tue, May 26, 2015 at 7:36 AM, Mike Snitzer snit...@redhat.com wrote: On Fri, May 22 2015 at 2:18pm -0400, Ming Lin m...@kernel.org wrote: From: Kent Overstreet kent.overstr...@gmail.com The way the block layer is currently written, it goes to great lengths to avoid having to split bios;

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

2015-05-26 Thread Mike Snitzer
On Fri, May 22 2015 at 2:18pm -0400, Ming Lin m...@kernel.org wrote: From: Kent Overstreet kent.overstr...@gmail.com The way the block layer is currently written, it goes to great lengths to avoid having to split bios; upper layer code (such as bio_add_page()) checks what the underlying

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

2015-05-26 Thread NeilBrown
On Tue, 26 May 2015 16:34:14 +0100 Alasdair G Kergon a...@redhat.com wrote: On Tue, May 26, 2015 at 08:02:08AM -0700, Ming Lin wrote: Now bio_add_page() can build lager bios. And blk_queue_split() can split the bios in -make_request() if needed. But why not try to make the bio the right

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

2015-05-26 Thread Mike Snitzer
On Tue, May 26 2015 at 11:02am -0400, Ming Lin m...@kernel.org wrote: On Tue, May 26, 2015 at 7:36 AM, Mike Snitzer snit...@redhat.com wrote: On Fri, May 22 2015 at 2:18pm -0400, Ming Lin m...@kernel.org wrote: From: Kent Overstreet kent.overstr...@gmail.com The way the block layer

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

2015-05-26 Thread Ming Lin
On Tue, May 26, 2015 at 9:04 AM, Mike Snitzer snit...@redhat.com wrote: On Tue, May 26 2015 at 11:02am -0400, Ming Lin m...@kernel.org wrote: On Tue, May 26, 2015 at 7:36 AM, Mike Snitzer snit...@redhat.com wrote: On Fri, May 22 2015 at 2:18pm -0400, Ming Lin m...@kernel.org wrote:

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

2015-05-24 Thread NeilBrown
On Fri, 22 May 2015 11:18:33 -0700 Ming Lin wrote: > From: Kent Overstreet > > The way the block layer is currently written, it goes to great lengths > to avoid having to split bios; upper layer code (such as bio_add_page()) > checks what the underlying device can handle and tries to always

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

2015-05-24 Thread NeilBrown
On Fri, 22 May 2015 11:18:33 -0700 Ming Lin m...@kernel.org wrote: From: Kent Overstreet kent.overstr...@gmail.com The way the block layer is currently written, it goes to great lengths to avoid having to split bios; upper layer code (such as bio_add_page()) checks what the underlying

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

2015-05-22 Thread Ming Lin
From: Kent Overstreet The way the block layer is currently written, it goes to great lengths to avoid having to split bios; upper layer code (such as bio_add_page()) checks what the underlying device can handle and tries to always create bios that don't need to be split. But this approach

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

2015-05-22 Thread Ming Lin
From: Kent Overstreet kent.overstr...@gmail.com The way the block layer is currently written, it goes to great lengths to avoid having to split bios; upper layer code (such as bio_add_page()) checks what the underlying device can handle and tries to always create bios that don't need to be split.