From 7795e004d36e779abdf77f8771488595839e4bee Mon Sep 17 00:00:00 2001
From: Michael Vrable <mvrable@cs.ucsd.edu>
Date: Mon, 23 Aug 2010 10:21:37 -0700
Subject: [PATCH] Make cache size run-time configurable.

---
 bluesky/bluesky.h | 3 +++
 bluesky/init.c    | 5 ++++-
 bluesky/log.c     | 7 ++-----
 3 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/bluesky/bluesky.h b/bluesky/bluesky.h
index 60a3842..ca3d130 100644
--- a/bluesky/bluesky.h
+++ b/bluesky/bluesky.h
@@ -33,6 +33,9 @@ typedef struct {
     /* Should frontends handle requests serially or allow operations to proceed
      * in parallel? */
     int sync_frontends;
+
+    /* Target size of the disk cache at the proxy, in kilobytes. */
+    int cache_size;
 } BlueSkyOptions;
 
 extern BlueSkyOptions bluesky_options;
diff --git a/bluesky/init.c b/bluesky/init.c
index 1db4283..2ac2f23 100644
--- a/bluesky/init.c
+++ b/bluesky/init.c
@@ -15,7 +15,9 @@
 
 int bluesky_verbose = 0;
 
-BlueSkyOptions bluesky_options;
+BlueSkyOptions bluesky_options = {
+    .cache_size = 1024*1024,         // Default cache size is 1 GiB
+};
 
 /* Maximum number of threads to use in any particular thread pool, or -1 for no
  * limit */
@@ -47,6 +49,7 @@ static struct {
     {"BLUESKY_OPT_WRITETHROUGH", &bluesky_options.writethrough_cache},
     {"BLUESKY_OPT_SYNC_INODE_FETCH", &bluesky_options.sync_inode_fetches},
     {"BLUESKY_OPT_SYNC_FRONTENDS", &bluesky_options.sync_frontends},
+    {"BLUESKY_CACHE_SIZE", &bluesky_options.cache_size},
     {NULL, NULL}
 };
 
diff --git a/bluesky/log.c b/bluesky/log.c
index c8641b7..1fe6176 100644
--- a/bluesky/log.c
+++ b/bluesky/log.c
@@ -38,10 +38,6 @@
 // no absolute guarantees on the size of a log segment.
 #define LOG_SEGMENT_SIZE (1 << 22)
 
-// Target amount of disk space to use for the journal and cache files, in
-// kilobytes.
-#define DISK_CACHE_SIZE_TARGET (64 * 1024)
-
 #define HEADER_MAGIC 0x676f4c0a
 #define FOOTER_MAGIC 0x2e435243
 
@@ -521,7 +517,8 @@ void bluesky_cachefile_gc(BlueSkyFS *fs)
             g_print("\n");
 
             gboolean deletion_candidate = FALSE;
-            if (g_atomic_int_get(&fs->log->disk_used) > DISK_CACHE_SIZE_TARGET
+            if (g_atomic_int_get(&fs->log->disk_used)
+                    > bluesky_options.cache_size
                 && g_atomic_int_get(&cachefile->refcount) == 0
                 && g_atomic_int_get(&cachefile->mapcount) == 0)
             {
-- 
2.20.1