From 200e3565550263cafd07bd71afa88a4e2273fb70 Mon Sep 17 00:00:00 2001
From: bobijam <bobijam>
Date: Wed, 6 Aug 2008 02:17:08 +0000
Subject: [PATCH] Branch b1_6 b=16205 i=joahnn, adilger

low-memory tunings for BlueGene/L.
---
 lustre/include/lustre_dlm.h        | 5 +++++
 lustre/llite/llite_lib.c           | 9 +++++++--
 lustre/obdclass/class_obd.c        | 9 +++++++--
 lustre/obdfilter/filter_internal.h | 2 +-
 4 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/lustre/include/lustre_dlm.h b/lustre/include/lustre_dlm.h
index 2aa9080..967cc96 100644
--- a/lustre/include/lustre_dlm.h
+++ b/lustre/include/lustre_dlm.h
@@ -59,7 +59,12 @@ struct obd_device;
 
 #define OBD_LDLM_DEVICENAME  "ldlm"
 
+#ifdef HAVE_BGL_SUPPORT
+/* 1.5 times the maximum 128 tasks available in VN mode */
+#define LDLM_DEFAULT_LRU_SIZE 196
+#else
 #define LDLM_DEFAULT_LRU_SIZE (100 * num_online_cpus())
+#endif
 #define LDLM_DEFAULT_MAX_ALIVE (cfs_time_seconds(36000))
 
 typedef enum {
diff --git a/lustre/llite/llite_lib.c b/lustre/llite/llite_lib.c
index f18eb7c..ff3f128 100644
--- a/lustre/llite/llite_lib.c
+++ b/lustre/llite/llite_lib.c
@@ -90,10 +90,15 @@ static struct ll_sb_info *ll_init_sbi(void)
 
         si_meminfo(&si);
         pages = si.totalram - si.totalhigh;
-        if (pages >> (20 - CFS_PAGE_SHIFT) < 512)
+        if (pages >> (20 - CFS_PAGE_SHIFT) < 512) {
+#ifdef HAVE_BGL_SUPPORT
+                sbi->ll_async_page_max = pages / 4;
+#else
                 sbi->ll_async_page_max = pages / 2;
-        else
+#endif
+        } else {
                 sbi->ll_async_page_max = (pages / 4) * 3;
+        }
         sbi->ll_ra_info.ra_max_pages = min(pages / 32,
                                            SBI_DEFAULT_READAHEAD_MAX);
         sbi->ll_ra_info.ra_max_read_ahead_whole_pages =
diff --git a/lustre/obdclass/class_obd.c b/lustre/obdclass/class_obd.c
index a3208f8..e5cdd9a 100644
--- a/lustre/obdclass/class_obd.c
+++ b/lustre/obdclass/class_obd.c
@@ -570,8 +570,13 @@ int init_obdclass(void)
         for (i = 0; i < class_devno_max(); i++)
                 obd_devs[i] = NULL;
 
-        /* Default the dirty page cache cap to 1/2 of system memory */
-        obd_max_dirty_pages = num_physpages / 2;
+        /* Default the dirty page cache cap to 1/2 of system memory.
+         * For clients with less memory, a larger fraction is needed
+         * for other purposes (mostly for BGL). */
+        if (num_physpages <= 512 << (20 - CFS_PAGE_SHIFT))
+                obd_max_dirty_pages = num_physpages / 4;
+        else
+                obd_max_dirty_pages = num_physpages / 2;
 
         err = obd_init_caches();
         if (err)
diff --git a/lustre/obdfilter/filter_internal.h b/lustre/obdfilter/filter_internal.h
index 65a46b7..668b3d4 100644
--- a/lustre/obdfilter/filter_internal.h
+++ b/lustre/obdfilter/filter_internal.h
@@ -79,7 +79,7 @@ struct filter_mod_data {
         int              fmd_refcount;  /* reference counter - list holds 1 */
 };
 
-#ifdef BGL_SUPPORT
+#ifdef HAVE_BGL_SUPPORT
 #define FILTER_FMD_MAX_NUM_DEFAULT 128 /* many active files per client on BGL */
 #else
 #define FILTER_FMD_MAX_NUM_DEFAULT  32
-- 
1.8.3.1