Re: [HACKERS] can shared cache be swapped to disk?

2011-01-05 Thread Dimitri Fontaine
Jeff Janes jeff.ja...@gmail.com writes: (top doesn't distinguish between memory that has been requested but never accessed, versus memory that has been accessed and then truly swapped out to disk. So unless you first let it run to steady-state before applying pressure, it is hard to interpret

Re: [HACKERS] can shared cache be swapped to disk?

2011-01-04 Thread Jeff Janes
On Sun, Dec 19, 2010 at 6:14 AM, Martijn van Oosterhout klep...@svana.org wrote: On Sat, Dec 18, 2010 at 11:59:33PM -0800, Jeff Janes wrote: On Sat, Dec 18, 2010 at 10:11 PM, flyusa2010 fly flyusa2...@gmail.com wrote: hi, folks! I see that shared cache is implemented by system v shared

Re: [HACKERS] can shared cache be swapped to disk?

2011-01-04 Thread Martijn van Oosterhout
On Tue, Jan 04, 2011 at 09:51:05AM -0800, Jeff Janes wrote: Correct. The kernel ignores locking requests because it's a great way to DOS a machine. For example, mlock() of large blocks of memory is also not permitted for similar reasons. Does it ignore such requests in general, or only

Re: [HACKERS] can shared cache be swapped to disk?

2011-01-04 Thread Jeff Janes
On Tue, Jan 4, 2011 at 2:52 PM, Martijn van Oosterhout klep...@svana.org wrote: On Tue, Jan 04, 2011 at 09:51:05AM -0800, Jeff Janes wrote: Correct. The kernel ignores locking requests because it's a great way to DOS a machine. For example, mlock() of large blocks of memory is also not

Re: [HACKERS] can shared cache be swapped to disk?

2010-12-19 Thread Jeff Janes
On Sat, Dec 18, 2010 at 10:11 PM, flyusa2010 fly flyusa2...@gmail.com wrote: hi, folks! I see that shared cache is implemented by system v shared memory. I wonder whether data in this area can be swapped out to disk. Isn't it bad that we read data from disk, put data in shared cache, and

Re: [HACKERS] can shared cache be swapped to disk?

2010-12-19 Thread Martijn van Oosterhout
On Sat, Dec 18, 2010 at 11:59:33PM -0800, Jeff Janes wrote: On Sat, Dec 18, 2010 at 10:11 PM, flyusa2010 fly flyusa2...@gmail.com wrote: hi, folks! I see that shared cache is implemented by system v shared memory. I wonder whether data in this area can be swapped out to disk. Isn't it bad

[HACKERS] can shared cache be swapped to disk?

2010-12-18 Thread flyusa2010 fly
hi, folks! I see that shared cache is implemented by system v shared memory. I wonder whether data in this area can be swapped out to disk. Isn't it bad that we read data from disk, put data in shared cache, and finally data in shared cache is swapped to disk again! Why not use