tiny updates to the doc of huge pages

diff --git a/ChangeLog b/ChangeLog
index 6ca3d3e..b388b9d 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -27,6 +27,7 @@ SimGrid (3.16) UNRELEASED
  SMPI
   - New algorithm to privatize globals: dlopen, with dynamic loading tricks
   - New option: smpi/keep-temps to not cleanup temp files
+  - Support for sparse privatized malloc with SMPI_PARTIAL_SHARED_MALLOC()
 
  XBT
   - Replay: New function xbt_replay_action_get():

diff --git a/doc/doxygen/options.doc b/doc/doxygen/options.doc
index d5a8f54..3fad32c 100644 (file)
--- a/doc/doxygen/options.doc
+++ b/doc/doxygen/options.doc
@@ -1110,7 +1110,7 @@ returns a new adress, but it only points to a shadow bloc: its memory
 area is mapped on a 1MiB file on disk. If the returned bloc is of size
 N MiB, then the same file is mapped N times to cover the whole bloc. 
 At the end, no matter how many SMPI_SHARED_MALLOC you do, this will
-only consume 1 MiB in memory.
+only consume 1 MiB in memory. 
 
 You can disable this behavior and come back to regular mallocs (for
 example for debugging purposes) using \c "no" as a value.
@@ -1121,7 +1121,7 @@ can use SMPI_PARTIAL_SHARED_MALLOC(size, offsets, offsets_count).
 
 As an example,
 
-\code{.unparsed}
+\code{.C}
     mem = SMPI_PARTIAL_SHARED_MALLOC(500, {27,42 , 100,200}, 2);
 \endcode
 
@@ -1130,21 +1130,21 @@ are shared and other area remain private.
 
 Then, it can be deallocated by calling SMPI_SHARED_FREE(mem).
 
-When smpi/shared-malloc:global is used, it is possible to optimize even
-further the memory consumption and the simulation time by using huge pages.
-To do so, it is required to mount a hugetlbfs on your system and allocate
+When smpi/shared-malloc:global is used, the memory consumption problem
+is solved, but it may induce too much load on the kernel's pages table. 
+In this case, you should use huge pages so that we create only one
+entry per Mb of malloced data instead of one entry per 4k.
+To activate this, you must mount a hugetlbfs on your system and allocate
 at least one huge page:
 
-\code{.unparsed}
+\code{.sh}
     mkdir /home/huge
     sudo mount none /home/huge -t hugetlbfs -o rw,mode=0777
-    sudo sh -c 'echo 1 > /proc/sys/vm/nr_hugepages'
+    sudo sh -c 'echo 1 > /proc/sys/vm/nr_hugepages' # echo more if you need more
 \endcode
 
-Note that at least one huge page is required for smpirun, but you can set
-an higher number of huge pages in nr_hugepages (e.g. "echo 27").
 Then, you can pass the option --cfg=smpi/shared-malloc-hugepage:/home/huge
-to smpirun.
+to smpirun to actually activate the huge page support in shared mallocs.
 
 \subsection options_model_smpi_wtime smpi/wtime: Inject constant times for calls to MPI_Wtime
 
@@ -1304,6 +1304,7 @@ It can be done by using XBT. Go to \ref XBT_log for more details.
 - \c smpi/privatization: \ref options_smpi_privatization
 - \c smpi/send-is-detached-thresh: \ref options_model_smpi_detached
 - \c smpi/shared-malloc: \ref options_model_smpi_shared_malloc
+- \c smpi/shared-malloc-hugepage: \ref options_model_smpi_shared_malloc
 - \c smpi/simulate-computation: \ref options_smpi_bench
 - \c smpi/test: \ref options_model_smpi_test
 - \c smpi/wtime: \ref options_model_smpi_wtime