Re: Contributing to the device driver staging section of the linux tree
On Tue, Apr 15, 2014 at 10:57:28PM +0530, Kashyap Gada wrote: > Hello, > > I want to re start the code clean up stuff in the staging branch of drivers in > the linux tree. I have done this before some time back on the 2.6 branch. I > want to get back to atleast start off again (I am learning developing device > drivers) to be active in the community. > > My question is that the latest linux kernel is 3.x there have been so many > versions of it since 2.6. So how to decide which branch we should be working > on > and which is relevant enought in todays time. You always have to work on the latest development kernel tree, as we do not do new work on older releases. See the Documentation/kernel_development/ documentation for how this all works. Hope this helps, greg k-h ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Contributing to the device driver staging section of the linux tree
Hello, I want to re start the code clean up stuff in the staging branch of drivers in the linux tree. I have done this before some time back on the 2.6 branch. I want to get back to atleast start off again (I am learning developing device drivers) to be active in the community. My question is that the latest linux kernel is 3.x there have been so many versions of it since 2.6. So how to decide which branch we should be working on and which is relevant enought in todays time. Thanks Kashyap Gada gada.kash...@gmail.com ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Questions regarding del_timer_sync() and re-registering timers
Hi. The conventional wisdom when mixing del_timer_sync() with timers
that re-register themselves is that the caller must ensure that re-registration
does not happen.
>From kernel/timer.c:
* Synchronization rules: Callers must prevent restarting of the timer,
* otherwise this function is meaningless.
Now, the pseudo-code for del_timer_sync and try_to_del_timer_sync looks
something like this (ignoring the lock manipulation):
while (1) {
if (timer is not running) {
if timer is pending then detach it
break
}
else {
sleep
}
}
So that the loop continues to spin until the timer function is no longer
running at which point the kernel checks the pending list and removes it if
necessary.
Q: So given this construct, why is it imperative that the timer
function not re-register itself?
I could understand that restriction if the timer function might be running on
another CPU when the "if timer is pending then detach" step is executed but
it's not obvious to me how that's possible since base->lock is owned at
that point (not shown in the pseudocode)?
Can someone briefly point out what I've missed?
Jimmie
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Re: cgroups: cannot write on file memory.oom_control
Hi, Hedi, This sequence works for me: echo 0 > /sys/fs/cgroup/memory/memory.use_hierarchy mkdir /sys/fs/cgroup/memory/0 Then, the following two commands changes the value of oom_kill_disable: echo 1 > /sys/fs/cgroup/memory/0/memory.oom_control echo 0 > /sys/fs/cgroup/memory/0/memory.oom_control For more info, please look for the text about enabling/disabling use_hierarchy in section 6, http://lxr.free-electrons.com/source/Documentation/cgroups/memory.txt. Regards, Rami Rosen http://ramirose.wix.com/ramirosen On Mon, Apr 14, 2014 at 12:22 PM, Hedi Boufaied wrote: > Hi everyone, > > I am working with cgroups on OpenSuse (over VirtualBox) and I cannot disable > the OOM killer by writing to the file memory.oom_control: > >> echo 1 > memory.oom_control >> -bash: echo: write error: Invalid argument > > I can change the memory limit and several other settings by writing to the > appropriate files (like memory.limit_in_bytes) but I could never write to > file memory.oom_control although I am root. > > I saw someone posted a similar issue a few days ago but there was no > reply... > > I have copied below the sequence of command I am using. Any idea what could > be the issue ? > > Thanks in advance for your help! > > Hedi > > > > > /sys/fs> su - root > > /sys/fs> cd cgroup > > /sys/fs/cgroup> cgcreate -g memory:/mygroup > > /sys/fs/cgroup> cd memory/mygroup > > /sys/fs/cgroup/memory/mygroup> echo 32M > memory.limit_in_bytes > > /sys/fs/cgroup/memory/mygroup> cat memory.limit_in_bytes > 33554432 > > /sys/fs/cgroup/memory/mygroup> echo 1 > memory.oom_control > -bash: echo: write error: Invalid argument > > /sys/fs/cgroup/memory/mygroup> cat memory.oom_control > oom_kill_disable 0 > under_oom 0 > > --- > ___ > Kernelnewbies mailing list > Kernelnewbies@kernelnewbies.org > http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies > ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
