Re: About Intel I/OAT support in open-iscsi
Or Gerlitz wrote: > Mike Christie wrote: >> I am not sure what you are asking. Did you look at the patches? > > I gave it quick look before asking, I looked now again and I think > to understand this better - lets see if I'm in the correct direction: > > The I/OAT related kernel code serves the TCP stack for coping data > from the skb to the consumer buffer - for user space consumers this > is fairly simple and done behind the kernel cover. For kernel consumers > such as iscsi - things go a bit complex as there's richer API and some > flavors of it may not be applicable to use the dma functionality - or the > other way around - the dma functionality has to be exported/used by the > network stack consumer - namely iscsi, nfs, gfs, etc. So this patch set Something like that. However, I do not know about other code. It seems like some nfs code uses kernel_recvmsg so it would be fine. Maybe the rpc code uses recvmsg and could be fine but some data transfer code uses a tcp_read_sock and skb_copy_bits and so it would need changes like iscsi. I think gfs2 sends data over block/scsi devices so this is only applicable if it was using tcp sockets and a API that was not converted already for locking data or metadata. Something like nbd looks fine as is. > does changes both in the network internals/api and in iscsi logic. > --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "open-iscsi" group. To post to this group, send email to open-iscsi@googlegroups.com To unsubscribe from this group, send email to open-iscsi+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/open-iscsi -~--~~~~--~~--~--~---
Re: About Intel I/OAT support in open-iscsi
Mike Christie wrote: > I am not sure what you are asking. Did you look at the patches? I gave it quick look before asking, I looked now again and I think to understand this better - lets see if I'm in the correct direction: The I/OAT related kernel code serves the TCP stack for coping data from the skb to the consumer buffer - for user space consumers this is fairly simple and done behind the kernel cover. For kernel consumers such as iscsi - things go a bit complex as there's richer API and some flavors of it may not be applicable to use the dma functionality - or the other way around - the dma functionality has to be exported/used by the network stack consumer - namely iscsi, nfs, gfs, etc. So this patch set does changes both in the network internals/api and in iscsi logic. Or. --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "open-iscsi" group. To post to this group, send email to open-iscsi@googlegroups.com To unsubscribe from this group, send email to open-iscsi+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/open-iscsi -~--~~~~--~~--~--~---
Re: About Intel I/OAT support in open-iscsi
Or Gerlitz wrote: > Mike Christie wrote: >>> Does open-iscsi support I/OAT now? If so, from which version? >> No. It uses some network API that is not converted to support I/OAT. The >> intel guys have sent patches to add it, but they were a little behind >> upstream so their patches would break. I think they are working on it still. > Mike, Here's a pointer for the patches > http://www.mail-archive.com/open-iscsi@googlegroups.com/msg00388.html - > and now after saving you 5sec of work... a question comes: can you or > Supreeth help me get educated what makes the open iscsi usage of the > network API not applicable to use receive copy offload by the kernel > I/OAT engine - such that both the network stack and the iscsi code has I am not sure what you are asking. Did you look at the patches? The network api has be aware of the dma functionality. Check out tcp_recvmsg's NET_DMA ifdefs or check out the last patch for iscsi that has us use the dma helpers that Supreeth exported. The net functions we used when Supreeth made the patch did not support ioat like how tcp_recvmsg did and the function we use today also does not. Maybe Supreeth could have thought of a way for iscsi to use some new network helper or API in a way that hid if it was using ioat or not, like if we used kernel_recvmsg/tcp_recvmsg, but he did not so that is why the iscsi code had to be patched as well as the network code. Does that answer your question or were you asking something else? > to be patched? for example, does the NFS kernel code can use I/OAT as it > is now? > > thanks, > > Or. > > > > > > --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "open-iscsi" group. To post to this group, send email to open-iscsi@googlegroups.com To unsubscribe from this group, send email to open-iscsi+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/open-iscsi -~--~~~~--~~--~--~---
Re: About Intel I/OAT support in open-iscsi
Mike Christie wrote: >> Does open-iscsi support I/OAT now? If so, from which version? > No. It uses some network API that is not converted to support I/OAT. The > intel guys have sent patches to add it, but they were a little behind > upstream so their patches would break. I think they are working on it still. Mike, Here's a pointer for the patches http://www.mail-archive.com/open-iscsi@googlegroups.com/msg00388.html - and now after saving you 5sec of work... a question comes: can you or Supreeth help me get educated what makes the open iscsi usage of the network API not applicable to use receive copy offload by the kernel I/OAT engine - such that both the network stack and the iscsi code has to be patched? for example, does the NFS kernel code can use I/OAT as it is now? thanks, Or. --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "open-iscsi" group. To post to this group, send email to open-iscsi@googlegroups.com To unsubscribe from this group, send email to open-iscsi+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/open-iscsi -~--~~~~--~~--~--~---
Re: About Intel I/OAT support in open-iscsi
Simon Xu 徐浩 wrote: > Hi, > > I need Intel I/OAT support in open-iscsi. I'm now using RHEL 5.3. I cannot > tell if RHEL 5.3 kernel supports I/OAT or not by reading its source code. > It would be great help if anyone could answer the following questions for > me. > > 1) Do open-iscsi modules in RHEL 5.3 kernel support I/OAT? No. It uses some network API that is not converted to support I/OAT. > 2) Does open-iscsi support I/OAT now? If so, from which version? > Nope. The intel guys have sent patches to add it, but they were a little behind upstream so their patches would break. I think they are working on it still. You can search the list to find some of their posts (if cannot find it and really care let me know and I will try to find it). > Thank you! > > Regards, > Simon > > > > --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "open-iscsi" group. To post to this group, send email to open-iscsi@googlegroups.com To unsubscribe from this group, send email to open-iscsi+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/open-iscsi -~--~~~~--~~--~--~---
RE: About Intel I/OAT support in open-iscsi
I don't think open-iscsi needs to support that. You just load the relevant I/O AT modules. This should get automatically loaded if the system BIOS enables I/O AT (requires chipset support). Once you have done that the network has a performance boost and you can do all you want from normal network things including open-iscsi. Thanks, Shyam From: open-iscsi@googlegroups.com [mailto:open-is...@googlegroups.com] On Behalf Of Simon Xu ?? Sent: Monday, March 16, 2009 3:25 PM To: open-iscsi@googlegroups.com Subject: About Intel I/OAT support in open-iscsi Hi, I need Intel I/OAT support in open-iscsi. I'm now using RHEL 5.3. I cannot tell if RHEL 5.3 kernel supports I/OAT or not by reading its source code. It would be great help if anyone could answer the following questions for me. 1) Do open-iscsi modules in RHEL 5.3 kernel support I/OAT? 2) Does open-iscsi support I/OAT now? If so, from which version? Thank you! Regards, Simon --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "open-iscsi" group. To post to this group, send email to open-iscsi@googlegroups.com To unsubscribe from this group, send email to open-iscsi+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/open-iscsi -~--~~~~--~~--~--~---
About Intel I/OAT support in open-iscsi
Hi, I need Intel I/OAT support in open-iscsi. I'm now using RHEL 5.3. I cannot tell if RHEL 5.3 kernel supports I/OAT or not by reading its source code. It would be great help if anyone could answer the following questions for me. 1) Do open-iscsi modules in RHEL 5.3 kernel support I/OAT? 2) Does open-iscsi support I/OAT now? If so, from which version? Thank you! Regards, Simon --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "open-iscsi" group. To post to this group, send email to open-iscsi@googlegroups.com To unsubscribe from this group, send email to open-iscsi+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/open-iscsi -~--~~~~--~~--~--~---
