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A couple of months ago I reported some problems with a batch of Tyan K8SSA (S3870) based machines. We are continuing to have an odd problem with these boxes, and if anyone has seen something similar elsewhere, I'd appreciate hearing about it. These boxes are running Centos 4.4 x86_64 with kernel 2.6.9-42.0.3.ELsmp. They are dual Opteron 265's (dual core) with 4x2GB DIMM's. The

There are cases that users want to shrink balloon pages after the pagecache depleted. The conservative_shrinker lets the shrinker shrink balloon pages when all the pagecache has been reclaimed. Signed-off-by: Wei Wang <wei.w.wang at intel.com> --- drivers/virtio/virtio_balloon.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git

There are cases that users want to shrink balloon pages after the pagecache depleted. The conservative_shrinker lets the shrinker shrink balloon pages when all the pagecache has been reclaimed. Signed-off-by: Wei Wang <wei.w.wang at intel.com> --- drivers/virtio/virtio_balloon.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git

Hi all, This is not really a libvirt issue but I'm hoping some of the smart folks here will know more about this problem... We have noticed when running some HPC applications on our OpenStack (libvirt+KVM) cloud that the same application occasionally performs much worse (4-5x slowdown) than normal. We can reproduce this quite easily by filling pagecache (i.e. dd-ing a single large file to

On Monday, February 10, 2020 11:57 AM, Tetsuo Handa wrote: > Then, "node-A's NR_FILE_PAGES is already 0 and node-B's NR_FILE_PAGES is > not 0, but allocation request which triggered this shrinker wants to allocate > from only node-A" > would be confused by this change, for the pagecache pages for allocating > thread's interested node are already depleted but

On Monday, February 10, 2020 11:57 AM, Tetsuo Handa wrote: > Then, "node-A's NR_FILE_PAGES is already 0 and node-B's NR_FILE_PAGES is > not 0, but allocation request which triggered this shrinker wants to allocate > from only node-A" > would be confused by this change, for the pagecache pages for allocating > thread's interested node are already depleted but

Hi, I was wondering about the ARC and its interaction with the VM pagecache... When a file on a ZFS filesystem is mmaped, does the ARC cache get mapped to the process'' virtual memory? Or is there another copy? -Manoj

On Tue, Nov 14, 2017 at 10:23:56AM -0700, Blair Bethwaite wrote: > Hi all, > > This is not really a libvirt issue but I'm hoping some of the smart folks > here will know more about this problem... > > We have noticed when running some HPC applications on our OpenStack > (libvirt+KVM) cloud that the same application occasionally performs much > worse (4-5x slowdown)

Thanks for the reply Daniel, However I think you slightly misunderstood the scenario... On 14 November 2017 at 10:32, Daniel P. Berrange <berrange@redhat.com> wrote: > IOW, if your application has a certain expectation of performance that can only > be satisfied by having the KVM guest backed by huge pages, then you should > really change to explicitly reserve huge pages for the

On Saturday, February 8, 2020 8:33 PM, Tetsuo Handa wrote: > > Is this NUMA aware? Can "node-A's NR_FILE_PAGES is already 0 and > node-B's NR_FILE_PAGES is not 0, but allocation request which triggered this > shrinker wants to allocate from only node-B" happen? No, it's a global counter. >Can some thread keep > this shrinker defunctional by keep

On Saturday, February 8, 2020 8:33 PM, Tetsuo Handa wrote: > > Is this NUMA aware? Can "node-A's NR_FILE_PAGES is already 0 and > node-B's NR_FILE_PAGES is not 0, but allocation request which triggered this > shrinker wants to allocate from only node-B" happen? No, it's a global counter. >Can some thread keep > this shrinker defunctional by keep

Add a new field, VIRTIO_BALLOON_S_AVAIL, to virtio_balloon memory statistics protocol, corresponding to 'Available' in /proc/meminfo. It indicates to the hypervisor how big the balloon can be inflated without pushing the guest system to swap. This metric would be very useful in VM orchestration software to improve memory management of different VMs under overcommit. Signed-off-by: Igor

Add a new field, VIRTIO_BALLOON_S_AVAIL, to virtio_balloon memory statistics protocol, corresponding to 'Available' in /proc/meminfo. It indicates to the hypervisor how big the balloon can be inflated without pushing the guest system to swap. This metric would be very useful in VM orchestration software to improve memory management of different VMs under overcommit. Signed-off-by: Igor

Hi. Im writing a kernel module to extract some information from kernel, the module is working really fine in an AMD (AMD Athlon(tm) 64 X2 Dual Core Processor 3800+), but, when trying to run the module in a i7 (Intel(R) Core(TM) i7 CPU 930 @ 2.80GHz) Im facing some strange errors (see below). The kernel versions are just the same on both machines (2.6.34.10-0.2-xen #1 SMP x86_64 x86_64 x86_64

Hi. Im writing a kernel module to extract some information from kernel, the module is working really fine in an AMD (AMD Athlon(tm) 64 X2 Dual Core Processor 3800+), but, when trying to run the module in a i7 (Intel(R) Core(TM) i7 CPU 930 @ 2.80GHz) Im facing some strange errors (see below). The kernel versions are just the same on both machines (2.6.34.10-0.2-xen #1 SMP x86_64 x86_64 x86_64

Greetings Has libvirt dedicated page cache area for guest ? If not - what is the difference between cache='none' and cache='directsync' ? >The optional cache attribute controls the cache mechanism, possible >values are "default", "none", "writethrough", "writeback", "directsync" >(like "writethrough", but it

On Tue, Nov 14, 2017 at 10:52:03AM -0700, Blair Bethwaite wrote: > Thanks for the reply Daniel, > > However I think you slightly misunderstood the scenario... > > On 14 November 2017 at 10:32, Daniel P. Berrange <berrange@redhat.com> wrote: > > IOW, if your application has a certain expectation of performance that can only > > be satisfied by having the KVM guest

On 14 November 2017 at 10:56, Daniel P. Berrange <berrange@redhat.com> wrote: > Oh well THP usage inside the guest is then not really anything todo with > virt, just a regular Linux questions, so not sure libvirt is the best > place to ask. True, I just hoped you or one of the other devs might have some insight on reclaim behaviour that would provide a clue. I guess I'll try a

An interesting bug in RHEL 3(which affects CentOS 3) has been bantered around for a while. There are some kernel patches(beyond my scope right now) or some echo statements tht are used(this helped my situation). The newest 2.4.x kernels have these patches incorporated. Would centOS 3 go nuts if i installed the latest kernel from kernel.org? <btw the issue is that the 2.4.xx kernels

On Thu, Feb 06, 2020 at 04:01:47PM +0800, Wei Wang wrote: > There are cases that users want to shrink balloon pages after the > pagecache depleted. The conservative_shrinker lets the shrinker > shrink balloon pages when all the pagecache has been reclaimed. > > Signed-off-by: Wei Wang <wei.w.wang at intel.com> I'd rather avoid module parameters, but otherwise looks like