search for: starve

...the console, it sends a signal to the parent and then does another select. The problem is that the select doesn't actually read from the device, and will return immediately since their is still data pending until it is read. But it's the parent that reads the data. So the child actually starves the parent from reading the data by spinning and waiting for it to read the data. The fix I implemented was to have the child wait for a response from the parent before going on. Since there was already communication between the parent and child via a pipe, I used that. This time, the data return...

...the console, it sends a signal to the parent and then does another select. The problem is that the select doesn't actually read from the device, and will return immediately since their is still data pending until it is read. But it's the parent that reads the data. So the child actually starves the parent from reading the data by spinning and waiting for it to read the data. The fix I implemented was to have the child wait for a response from the parent before going on. Since there was already communication between the parent and child via a pipe, I used that. This time, the data return...

Hi All, I''m successfully using drbd on xen dom0''s across a 2 machine cluster. However I have one domU that refuses to start on one of the machines, but starts find on the other. Config files for domU and drbd are identical. Not sure where to start looking to diagnose the problem x-host-3:/etc/xen # xm create n-monitor Using config file "/etc/xen/vm/n-monitor".

Hello, If an ordinary user runs: -- snip -- cat > starv.c <<EOF main(){ char *point; while(1) { point = ( char * ) malloc(10000); }} EOF cc starv.c while true do ./a.out & done -- snip -- This will fast starv the operating system (FreeBSD 6.2). I have tried to limit the number of processes and the amount of memmory consumed (in login.conf). There is also a file /etc/malloc.conf

...annoyance (nbdcopy has already exited, and no further client will be connecting); but for a longer-running nbdkit server accepting parallel clients, it means any one client can trigger the SIGABRT by intentionally queueing multiple NBD_CMD_READ then disconnecting early, and thereby kill nbdkit and starve other clients. Whether it rises to the level of CVE depends on whether you consider one client being able to starve others a privilege escalation (if you are not using TLS, there are other ways for a bad client to starve peers; if you are using TLS, then the starved client has the same credentials...

...------------------------ Message: 4 Date: Fri, 15 Jun 2007 10:16:12 +0200 From: Christian Benvenuti <christian.benvenuti@libero.it> Subject: [LARTC] Re: PQ questions To: lartc@mailman.ds9a.nl Message-ID: <1181895372.2702.20.camel@benve-laptop> Content-Type: text/plain Hi, a class is starved only if those with higher priority are always (of pretty often) backlogged and do not give the lower priority classes a chance to transmit. Therefore, if you transmit at a rate smaller than your CPU/s and NIC/s can handle you will not experience any starving. For example, if you generate 50Mbit t...

Hi all, First, let me say I''ve been most impressed with how quickly and professionally people on this list ask and answer questions. Next, let me say that with which I need help is properly configuring strict PQ, and gathering certain stats. Specifically: - I need to create a priority queue with four queues (let''s say they are of high, medium, normal, and low priority) - I

...ock on this rwsem while they scan the extent tree, and if need_resched() they will drop the lock and schedule. The transaction commit needs to take a write lock for this rwsem for a very short period to switch out the commit roots. If there are a lot of threads doing this caching operation we can starve out the committers which slows everybody out. To address this we want to add this functionality to see if our rwsem has anybody waiting to take a write lock so we can drop it and schedule for a bit to allow the commit to continue. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com> ---...

I am looking for a simple way to guarantee to each flow going through my traffic control point 1/numflows of bandwidth. I thought using SFQ would do this effectively but it appears to be quite unfair: a very high speed download that fills the pipe easily starves smaller flows to the point where it becomes unusable (especially if they are at all interactive) Because numflows is dynamic, I''m not sure how I would have the bandwidth allocated to each flow change dynamically and automatically as flows are added and removed. Anyone have an idea how t...

Hello mailing list, i stand bevor a mystery and cannot explain it J. I want to do shaping and prioritization and I have done these following configurations and simulations. I can´t explain, that the combination of PRIO and TBF is much better than the HTB (with the prio parameter) alone or in combination with the SFQ. Here are my example configurations: 2 Traffic Classes http (80 = 0x50) and

Hello all, Just a quick note to let you all know that I have placed a bounty on Lauchpad to get bitrate peeling added to Vorbis. It is a feature that I think we would all like to have, and would probably pay something to get, but it hasn't been done. My request to you is to add to the bounty. I have seeded it with US$20, which is not enough to motivate a developer to get it done, but I am a

Similar to commit a2ac99905f1e ("vhost-net: set packet weight of tx polling to 2 * vq size"), we need a packet-based limit for handler_rx, too - elsewhere, under rx flood with small packets, tx can be delayed for a very long time, even without busypolling. The pkt limit applied to handle_rx must be the same applied by handle_tx, or we will get unfair scheduling between rx and tx. Tying

2014-05-07 11:01-0400, Waiman Long: > From: Peter Zijlstra <peterz at infradead.org> > > Because the qspinlock needs to touch a second cacheline; add a pending > bit and allow a single in-word spinner before we punt to the second > cacheline. I think there is an unwanted scenario on virtual machines: 1) VCPU sets the pending bit and start spinning. 2) Pending VCPU gets

2014-05-07 11:01-0400, Waiman Long: > From: Peter Zijlstra <peterz at infradead.org> > > Because the qspinlock needs to touch a second cacheline; add a pending > bit and allow a single in-word spinner before we punt to the second > cacheline. I think there is an unwanted scenario on virtual machines: 1) VCPU sets the pending bit and start spinning. 2) Pending VCPU gets

...40: htb qdiscs / | \ 20:1.... 30:1... 40:1... htb classes Then, if I''m right, when there is traffic in prio qdisc 1 to fully load link, users would get it distributed evenly but any low priority connections in qdiscs 2,3... would starve. Which is exactly what I want. Problem is, when I add filters to enqueue in HTB "below" prio qdisc, they aren''t working. I''m tried to make simplified version first: tc qdisc add dev eth0 root handle 1: htb tc class add dev eth0 parent 1: classid 1:1 htb rate 3000kbit...

...te: > The problem is not the order of the events, the problem is that in the > Windows version of the event loop, we only handle one event in each loop > iteration. The select() loop handles all events that have accumulated so > far, so regardless of the order it handles them, it never starves fd. At > least, that was what I thought, until I double checked and found out > that we actually don't in tinc 1.1 (tinc 1.0 is correct though). Sure, but changing the order of the events changes which one will be in that first slot. > So, we have to find a proper fix for both the P...

We used to have vhost_exceeds_weight() for vhost-net to: - prevent vhost kthread from hogging the cpu - balance the time spent between TX and RX This function could be useful for vsock and scsi as well. So move it to vhost.c. Device must specify a weight which counts the number of requests, or it can also specific a byte_weight which counts the number of bytes that has been processed.

...ms that don't have a decent source of entropy? Am I misinterpreting those discussions? We are having a problem deploying sshd (no prngd) where sshd refuses to start because it says theres not enough available entropy. Would disabling DSA in sshd prevent the system from becoming "entropy starved"? If I'm missing the point of the latest discussions, someone please correct me.... what was the real meaning of those discussions about using DSA keys in sshd? Thanks, Ed Ed Phillips <ed at udel.edu> University of Delaware (302) 831-6082 Systems Programmer III, Network and Sys...

...r to where the page is to be mapped, and just map it in the same place in every thread. Another possibility, and I'm not sure how to do this in LLVM, would be to sacrifice a register to hold the pointer to the unique per-thread structure. This would be worthwhile to me even on the register-starved x86-32. I suppose I could also just add a "hidden" (compiler-added and -maintained) argument to every function which is the pointer to the per-thread data. Using the normal thread-local storage scares me, because I don't know the performance implications. Obviously calling a s...

...disk I/O at the same time. One example would be the "updatedb" cronjob of the mlocate package. If you have say 5 VMs running on a physical System with a local software raid-1 as storage and the all run updatedb at the same time that causes all of them to run really slowly because the starve each other fighting over the disk. What is the best way to soften the impact of such a situation? Does it make sense to use a hardware raid instead? How would the raid type affect the performance in this case? Would the fact that the I/O load gets distributed across multiple spindles in, say,...