Re: [Fedora-ia64-list] RFC: Thoughts on SPARSE memory

[Doug Chapman <dchapman redhat com>]

lmbench-2.5 on a 4cpu HP Integrity rx4640 with discontiguous and sparse
memory configurations.  Kernel was kernel-2.6.17-1.2439.  Both kernels
were compiled on this system to ensure consistency.

I will run some stress testing to check for regressions on sparse.



                 L M B E N C H  2 . 0   S U M M A R Y
                 ------------------------------------


Basic system parameters
----------------------------------------------------
Host                 OS Description              Mhz

--------- ------------- ----------------------- ----
dist      Linux 2.6.17-          ia64-linux-gnu 1499
sparsemem Linux 2.6.17-          ia64-linux-gnu 1499

Processor, Processes - times in microseconds - smaller is better
----------------------------------------------------------------
Host                 OS  Mhz null null      open selct sig  sig  fork exec sh
                             call  I/O stat clos TCP   inst hndl proc proc proc
--------- ------------- ---- ---- ---- ---- ---- ----- ---- ---- ---- ---- ----
dist      Linux 2.6.17- 1499 0.03 0.30 23.6 27.1 8.474 0.33 3.40 107. 520. 2417
sparsemem Linux 2.6.17- 1499 0.03 0.29 23.7 27.0 8.477 0.33 3.47 108. 523. 2431

Context switching - times in microseconds - smaller is better
-------------------------------------------------------------
Host                 OS 2p/0K 2p/16K 2p/64K 8p/16K 8p/64K 16p/16K 16p/64K
                        ctxsw  ctxsw  ctxsw ctxsw  ctxsw   ctxsw   ctxsw
--------- ------------- ----- ------ ------ ------ ------ ------- -------
dist      Linux 2.6.17- 1.900 3.1900 6.5900 4.9200   10.7 4.76000    10.8
sparsemem Linux 2.6.17- 1.870 3.0000 6.2900 3.4600   10.6 4.50000    10.5

*Local* Communication latencies in microseconds - smaller is better
-------------------------------------------------------------------
Host                 OS 2p/0K  Pipe AF     UDP  RPC/   TCP  RPC/ TCP
                        ctxsw       UNIX         UDP         TCP conn
--------- ------------- ----- ----- ---- ----- ----- ----- ----- ----
dist      Linux 2.6.17- 1.900  46.8 68.2  35.5  28.1 198.5 212.3 97.9
sparsemem Linux 2.6.17- 1.870  48.0 70.3  48.2  42.8 198.9 211.8 98.2

File & VM system latencies in microseconds - smaller is better
--------------------------------------------------------------
Host                 OS   0K File      10K File      Mmap    Prot    Page
                        Create Delete Create Delete  Latency Fault   Fault
--------- ------------- ------ ------ ------ ------  ------- -----   -----
dist      Linux 2.6.17-                                33.6K 0.581
sparsemem Linux 2.6.17-                                34.4K 0.586

*Local* Communication bandwidths in MB/s - bigger is better
-----------------------------------------------------------
Host                OS  Pipe AF    TCP  File   Mmap  Bcopy  Bcopy  Mem   Mem
                             UNIX      reread reread (libc) (hand) read write
--------- ------------- ---- ---- ---- ------ ------ ------ ------ ---- -----
dist      Linux 2.6.17- 1332 183. 169. 43120M  746.7  713.9  481.0 746. 667.9
sparsemem Linux 2.6.17- 1323 183. 168. 43144M  746.8  702.0  481.3 746. 673.9

Memory latencies in nanoseconds - smaller is better
    (WARNING - may not be correct, check graphs)
---------------------------------------------------
Host                 OS   Mhz  L1 $   L2 $    Main mem    Guesses
--------- -------------  ---- ----- ------    --------    -------
dist      Linux 2.6.17-  1499     -      -           -    Bad mhz?
sparsemem Linux 2.6.17-  1499     -      -           -    Bad mhz?