On Thu, Apr 19, 2001 at 10:21:14AM +0200, Helge Hafting wrote:
> A program may know its own access pattern, but it don't usually know
> future access patterns. Well, backing up the entire fs could benefit
> from a something like this, you probably won't need the backup again
> soon. But this is
Helge Hafting wrote:
> Jeremy Jackson wrote:
>
> > currently all the kernel's heuristics are feed-back control loops.
> > what you are asking for is a feed-forward system: a way for the application
> > to tell kernel "I'm only reading this once, so after I'm done, throw it out
> > straight away"
Jeremy Jackson wrote:
> currently all the kernel's heuristics are feed-back control loops.
> what you are asking for is a feed-forward system: a way for the application
> to tell kernel "I'm only reading this once, so after I'm done, throw it out
> straight away"
> and "I'm only writing this
Jeremy Jackson wrote:
currently all the kernel's heuristics are feed-back control loops.
what you are asking for is a feed-forward system: a way for the application
to tell kernel "I'm only reading this once, so after I'm done, throw it out
straight away"
and "I'm only writing this data, so
Helge Hafting wrote:
Jeremy Jackson wrote:
currently all the kernel's heuristics are feed-back control loops.
what you are asking for is a feed-forward system: a way for the application
to tell kernel "I'm only reading this once, so after I'm done, throw it out
straight away"
and
On Thu, Apr 19, 2001 at 10:21:14AM +0200, Helge Hafting wrote:
A program may know its own access pattern, but it don't usually know
future access patterns. Well, backing up the entire fs could benefit
from a something like this, you probably won't need the backup again
soon. But this is
On Wed, Apr 18, 2001 at 11:21:46AM -0700, David Schwartz wrote:
>
>
> [..] If we assume the caching isn't helping [..]
If you know kernel data cache doesn't help your workload at all then you want
use O_DIRECT at least to save the CPU. You can run 2.4.4pre3aa3 or apply the
rawio-3 patch
: Is there a way to turn file caching off ?
Since the speed already drops before even writing to disk, I was thinking
that for "large memory" the management of the tree that contain which pages
are cached becomes high (since the tree is large and probably doesn't fit in
primary cache).
So if you
Bjorn Wesen wrote:
> A similar phenomenon happens when you simply copy a file - file A is read
> into the cache and file B is written to the cache, until the memory runs
> out. Then both start to flush at the same time, creating a horrible
in this example only file B needs uses IO when being
A similar phenomenon happens when you simply copy a file - file A is read
into the cache and file B is written to the cache, until the memory runs
out. Then both start to flush at the same time, creating a horrible
performance hit (especially if A and B are on the same disk :)
I don't know a
A similar phenomenon happens when you simply copy a file - file A is read
into the cache and file B is written to the cache, until the memory runs
out. Then both start to flush at the same time, creating a horrible
performance hit (especially if A and B are on the same disk :)
I don't know a
: Is there a way to turn file caching off ?
Since the speed already drops before even writing to disk, I was thinking
that for "large memory" the management of the tree that contain which pages
are cached becomes high (since the tree is large and probably doesn't fit in
primary cache).
So if you
On Wed, Apr 18, 2001 at 11:21:46AM -0700, David Schwartz wrote:
[..] If we assume the caching isn't helping [..]
If you know kernel data cache doesn't help your workload at all then you want
use O_DIRECT at least to save the CPU. You can run 2.4.4pre3aa3 or apply the
rawio-3 patch
> Is there a way to turn file caching off, or at least limit its size ?
>
> Thanks,
>
> Laurent Chavet
What benefit do you think you would get by limiting its size? All that
would do is ensure you hit the cache thrashing point sooner.
DS
-
To unsubscribe from
(more
than a CPU) used by bdflush and kswapd (and some others like kupdated).
Of course my real application doesn't go from /dev/zero to file but it
still only does sequential access, and it seems that I pay a high price
for the file caching when I'm not using it at all.
Is there a way to turn fi
(more
than a CPU) used by bdflush and kswapd (and some others like kupdated).
Of course my real application doesn't go from /dev/zero to file but it
still only does sequential access, and it seems that I pay a high price
for the file caching when I'm not using it at all.
Is there a way to turn fi
Is there a way to turn file caching off, or at least limit its size ?
Thanks,
Laurent Chavet
What benefit do you think you would get by limiting its size? All that
would do is ensure you hit the cache thrashing point sooner.
DS
-
To unsubscribe from this list: send
17 matches
Mail list logo
