Re: [PATCH 0/11] ksm: NUMA trees and page migration
On Tue, 2013-01-29 at 17:51 +0100, Andrea Arcangeli wrote: > Hi everyone, > > On Tue, Jan 29, 2013 at 04:26:13AM +0200, Izik Eidus wrote: > > On 01/29/2013 02:49 AM, Izik Eidus wrote: > > > On 01/29/2013 01:54 AM, Andrew Morton wrote: > > >> On Fri, 25 Jan 2013 17:53:10 -0800 (PST) > > >> Hugh Dickins wrote: > > >> > > >>> Here's a KSM series > > >> Sanity check: do you have a feeling for how useful KSM is? > > >> Performance/space improvements for typical (or atypical) workloads? > > >> Are people using it? Successfully? > > > > > > BTW, After thinking a bit about the word people, I wanted to see if > > normal users of linux > > that just download and install Linux (without using special > > virtualization product) are able to use it. > > So I google little bit for it, and found some nice results from users: > > http://serverascode.com/2012/11/11/ksm-kvm.html > > > > But I do agree that it provide justifying value only for virtualization > > users... > > Mostly for virtualization users indeed, but I'm aware of a few non > virtualization users too: > > 1) CERN has been one of the early adopters of KSM and initially they > were using KSM standalone (probably because not all hypervisors they > had to deal with were KVM/linux based, while all guests were linux and > in turn KSM capable). More info in the KSM paper page 2: > > http://www.kernel.org/doc/ols/2009/ols2009-pages-19-28.pdf > > However lately they're running KSM in combination with KVM too, and I'm > not sure if they're still using it standalone. See the "KSM shared" > blue area in slide 12 and the comparison with KSM on and off in slide > 14. > > https://indico.fnal.gov/getFile.py/access?contribId=18&sessionId=4&resId=0&materialId=slides&confId=4986 > > 2) all recent cyanogenmod in the performance menu in settings supports > KSM out of the box. You can run it for a while and then shut it > off. > > Not sure how good idea it is to leave it always on, but the only > efficient cellphone/tablet powersaving design (i.e. the wakelocks + > suspend to ram) still won't waste energy while the screen is off and > the phone has suspended to ram, regardless of KSM on or off. > > KSM NUMA awareness however is not needed on the cellphone :). Thanks for your sharing. Is there ksm benchmark? How to get it? > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majord...@kvack.org. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: mailto:"d...@kvack.org";> em...@kvack.org -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 0/11] ksm: NUMA trees and page migration
Hi everyone, On Tue, Jan 29, 2013 at 04:26:13AM +0200, Izik Eidus wrote: > On 01/29/2013 02:49 AM, Izik Eidus wrote: > > On 01/29/2013 01:54 AM, Andrew Morton wrote: > >> On Fri, 25 Jan 2013 17:53:10 -0800 (PST) > >> Hugh Dickins wrote: > >> > >>> Here's a KSM series > >> Sanity check: do you have a feeling for how useful KSM is? > >> Performance/space improvements for typical (or atypical) workloads? > >> Are people using it? Successfully? > > > BTW, After thinking a bit about the word people, I wanted to see if > normal users of linux > that just download and install Linux (without using special > virtualization product) are able to use it. > So I google little bit for it, and found some nice results from users: > http://serverascode.com/2012/11/11/ksm-kvm.html > > But I do agree that it provide justifying value only for virtualization > users... Mostly for virtualization users indeed, but I'm aware of a few non virtualization users too: 1) CERN has been one of the early adopters of KSM and initially they were using KSM standalone (probably because not all hypervisors they had to deal with were KVM/linux based, while all guests were linux and in turn KSM capable). More info in the KSM paper page 2: http://www.kernel.org/doc/ols/2009/ols2009-pages-19-28.pdf However lately they're running KSM in combination with KVM too, and I'm not sure if they're still using it standalone. See the "KSM shared" blue area in slide 12 and the comparison with KSM on and off in slide 14. https://indico.fnal.gov/getFile.py/access?contribId=18&sessionId=4&resId=0&materialId=slides&confId=4986 2) all recent cyanogenmod in the performance menu in settings supports KSM out of the box. You can run it for a while and then shut it off. Not sure how good idea it is to leave it always on, but the only efficient cellphone/tablet powersaving design (i.e. the wakelocks + suspend to ram) still won't waste energy while the screen is off and the phone has suspended to ram, regardless of KSM on or off. KSM NUMA awareness however is not needed on the cellphone :). -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 0/11] ksm: NUMA trees and page migration
On Mon, Jan 28, 2013 at 05:07:15PM -0800, Hugh Dickins wrote: > On Mon, 28 Jan 2013, Andrew Morton wrote: > > On Fri, 25 Jan 2013 17:53:10 -0800 (PST) > > Hugh Dickins wrote: > > > > > Here's a KSM series > > > > Sanity check: do you have a feeling for how useful KSM is? > > Performance/space improvements for typical (or atypical) workloads? > > Are people using it? Successfully? > > > > IOW, is it justifying itself? > > I have no idea! To me it's simply a technical challenge - and I agree > with your implication that that's not a good enough justification. > > I've added Marcelo and Gleb and the KVM list to the Cc: > my understanding is that it's the KVM guys who really appreciate KSM. > KSM is used on all RH kvm deployments for memory overcommit. I asked around for numbers and got the answer that it allows to squeeze anywhere between 10% and 100% more VMs on the same machine depends on a type of a guest OS and how similar workloads of VMs are. And management tries to keep VMs with similar OSes/workloads on the same host to gain more from KSM. -- Gleb. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 0/11] ksm: NUMA trees and page migration
On 01/29/2013 02:49 AM, Izik Eidus wrote: On 01/29/2013 01:54 AM, Andrew Morton wrote: On Fri, 25 Jan 2013 17:53:10 -0800 (PST) Hugh Dickins wrote: Here's a KSM series Sanity check: do you have a feeling for how useful KSM is? Performance/space improvements for typical (or atypical) workloads? Are people using it? Successfully? BTW, After thinking a bit about the word people, I wanted to see if normal users of linux that just download and install Linux (without using special virtualization product) are able to use it. So I google little bit for it, and found some nice results from users: http://serverascode.com/2012/11/11/ksm-kvm.html But I do agree that it provide justifying value only for virtualization users... Hi, I think it mostly used for virtualization, I know at least two products that it use - RHEV - RedHat enterprise virtualization, and my current place (Ravello Systems) that use it to do vm consolidation on top of cloud enviorments (Run multiple unmodified VMs on top of one vm you get from ec2 / rackspace / what so ever), for Ravello it is highly critical in achieving high rate of consolidation ratio... IOW, is it justifying itself? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 0/11] ksm: NUMA trees and page migration
On Mon, 28 Jan 2013, Andrew Morton wrote: > On Fri, 25 Jan 2013 17:53:10 -0800 (PST) > Hugh Dickins wrote: > > > Here's a KSM series > > Sanity check: do you have a feeling for how useful KSM is? > Performance/space improvements for typical (or atypical) workloads? > Are people using it? Successfully? > > IOW, is it justifying itself? I have no idea! To me it's simply a technical challenge - and I agree with your implication that that's not a good enough justification. I've added Marcelo and Gleb and the KVM list to the Cc: my understanding is that it's the KVM guys who really appreciate KSM. Hugh -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 0/11] ksm: NUMA trees and page migration
On 01/29/2013 01:54 AM, Andrew Morton wrote: On Fri, 25 Jan 2013 17:53:10 -0800 (PST) Hugh Dickins wrote: Here's a KSM series Sanity check: do you have a feeling for how useful KSM is? Performance/space improvements for typical (or atypical) workloads? Are people using it? Successfully? Hi, I think it mostly used for virtualization, I know at least two products that it use - RHEV - RedHat enterprise virtualization, and my current place (Ravello Systems) that use it to do vm consolidation on top of cloud enviorments (Run multiple unmodified VMs on top of one vm you get from ec2 / rackspace / what so ever), for Ravello it is highly critical in achieving high rate of consolidation ratio... IOW, is it justifying itself? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 0/11] ksm: NUMA trees and page migration
On Fri, 25 Jan 2013 17:53:10 -0800 (PST) Hugh Dickins wrote: > Here's a KSM series Sanity check: do you have a feeling for how useful KSM is? Performance/space improvements for typical (or atypical) workloads? Are people using it? Successfully? IOW, is it justifying itself? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH 0/11] ksm: NUMA trees and page migration
Here's a KSM series, based on mmotm 2013-01-23-17-04: starting with Petr's v7 "KSM: numa awareness sysfs knob"; then fixing the two issues we had with that, fully enabling KSM page migration on the way. (A different kind of KSM/NUMA issue which I've certainly not begun to address here: when KSM pages are unmerged, there's usually no sense in preferring to allocate the new pages local to the caller's node.) Petr, I have intentionally changed the titles of yours: partly because your "sysfs knob" understated it, but mainly because I think gmail is liable to assign 1/11 and 2/11 to your earlier December thread, making them vanish from this series. I hope a change of title prevents that. 1 ksm: allow trees per NUMA node 2 ksm: add sysfs ABI Documentation 3 ksm: trivial tidyups 4 ksm: reorganize ksm_check_stable_tree 5 ksm: get_ksm_page locked 6 ksm: remove old stable nodes more thoroughly 7 ksm: make KSM page migration possible 8 ksm: make !merge_across_nodes migration safe 9 mm: enable KSM page migration 10 mm: remove offlining arg to migrate_pages 11 ksm: stop hotremove lockdep warning Documentation/ABI/testing/sysfs-kernel-mm-ksm | 52 + Documentation/vm/ksm.txt |7 include/linux/ksm.h | 18 include/linux/migrate.h | 14 mm/compaction.c |2 mm/ksm.c | 566 +--- mm/memory-failure.c |7 mm/memory.c | 19 mm/memory_hotplug.c |3 mm/mempolicy.c| 11 mm/migrate.c | 61 - mm/page_alloc.c |6 12 files changed, 580 insertions(+), 186 deletions(-) Hugh -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
