* VM question - accounting of SysV SHM
@ 2007-10-17 20:49 Lee Revell
2007-10-17 20:58 ` Rik van Riel
0 siblings, 1 reply; 3+ messages in thread
From: Lee Revell @ 2007-10-17 20:49 UTC (permalink / raw)
To: lkml
Sorry to ask this question on the list but I've Googled and found nothing.
Is system V shared memory accounted for as Cached, or as normal
application memory?
I have an application that uses SysV shared memory and O_DIRECT for
all IO, but when it starts up, the cached column in vmstat seems to go
up by the amount of shared memory allocated.
Lee
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: VM question - accounting of SysV SHM
2007-10-17 20:49 VM question - accounting of SysV SHM Lee Revell
@ 2007-10-17 20:58 ` Rik van Riel
2007-10-17 21:11 ` Lee Revell
0 siblings, 1 reply; 3+ messages in thread
From: Rik van Riel @ 2007-10-17 20:58 UTC (permalink / raw)
To: Lee Revell; +Cc: lkml
On Wed, 17 Oct 2007 16:49:07 -0400
"Lee Revell" <rlrevell@joe-job.com> wrote:
> Sorry to ask this question on the list but I've Googled and found
> nothing.
>
> Is system V shared memory accounted for as Cached, or as normal
> application memory?
Cached.
Shared memory segments basically are tmpfs files.
--
"Debugging is twice as hard as writing the code in the first place.
Therefore, if you write the code as cleverly as possible, you are,
by definition, not smart enough to debug it." - Brian W. Kernighan
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: VM question - accounting of SysV SHM
2007-10-17 20:58 ` Rik van Riel
@ 2007-10-17 21:11 ` Lee Revell
0 siblings, 0 replies; 3+ messages in thread
From: Lee Revell @ 2007-10-17 21:11 UTC (permalink / raw)
To: Rik van Riel; +Cc: lkml
On 10/17/07, Rik van Riel <riel@redhat.com> wrote:
> On Wed, 17 Oct 2007 16:49:07 -0400
> "Lee Revell" <rlrevell@joe-job.com> wrote:
>
> > Sorry to ask this question on the list but I've Googled and found
> > nothing.
> >
> > Is system V shared memory accounted for as Cached, or as normal
> > application memory?
>
> Cached.
>
> Shared memory segments basically are tmpfs files.
Thanks!
Are there any plans to track it separately in a future kernel release?
I've also noticed that if huge pages are used for the shared memory,
they are not accounted for as cached - I have a 56GB huge page pool
but cached is only 6GB. Is this behavior specific to huge pages?
Finally, are these quirks documented anywhere?
Lee
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2007-10-17 21:11 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2007-10-17 20:49 VM question - accounting of SysV SHM Lee Revell
2007-10-17 20:58 ` Rik van Riel
2007-10-17 21:11 ` Lee Revell
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®