I am curious to know why jiffies is initialized with INITIAL_JIFFIES which
is -300 * HZ? It is mentioned in the source that jiffies, when initialized
with this value, will make it overflow in 5 minutes.
Can somebody tell me how it helps in dealing with jiffy overflow issues at a
later point in tim
Hi,
We had a problem where we were trying to debug why events/0 was taking 98%
of CPU time. I found that writing a âtâ to /proc/sysrq-trigger will dump the
stack traces of all processes. Unfortunately, events/0 was shown as running
and no stack trace was dumped for it:
==
ksoftirqd/0 S
>
> Hi Joel...
>
> Manish is right. Please notice that he talked about "why do we do copy
> on write (COW) if soon after child is forked, it quickly does exec()".
> So yes, COW has overhead, but imagine if parent ran first. COW will be
> triggered for parent address space, then child soon runs too.
On Wed, Dec 16, 2009 at 8:32 PM, Nagaprabhanjan Bellari
wrote:
> I learn a trick from Con Kolivas to purge cache...hopefully I recall
>> it correctly:
>> # tail /dev/zero
>>
>> wait for few seconds...watch out to not make it OOMand most likely
>> some (
>
> I learn a trick from Con Kolivas to purge cache...hopefully I recall
> it correctly:
> # tail /dev/zero
>
> wait for few seconds...watch out to not make it OOMand most likely
> some (if not at all) page cache will be purged out.
>
Are you sure? Does page cache get involved at all while rea
One can also write do a `echo 1 > /proc/sys/vm/drop_cache` to purge the page
cache.
-nagp
On Sat, Dec 12, 2009 at 12:50 PM, Joel Fernandes wrote:
> > My question is why the cache is growing even after O_SYNC flag? Even
> > fsync does not help. But deleting file freeing the cache.
> >
>
> Try O_D
The code snippet is in linux/kernel/softirq.c:__do_softirq():
==
do {
if (pending & 1) {
int preempt_count = preempt_count();
h->action(h);
if (preempt_count != preempt_count()) {
printk(KERN_CRIT "BUG: softirq: %p, %x,%x\n",
On Tue, Sep 29, 2009 at 3:34 PM, Leonidas . wrote:
>
>
> On Tue, Sep 29, 2009 at 3:31 PM, Nagaprabhanjan Bellari <
> nagp@gmail.com> wrote:
>
>> If you take /proc filesystem for example, you can write something to it
>> and can read something from it
If you take /proc filesystem for example, you can write something to it and
can read something from it depending on what you last wrote.
-nagp
On Fri, Sep 18, 2009 at 9:46 PM, Peter Teoh wrote:
> On Fri, Sep 18, 2009 at 9:07 PM, Leonidas . wrote:
> >
> >
> > On Fri, Sep 18, 2009 at 5:36 AM, Pet
