From 0e57b9b0865caf4b47deadbc17ef46bca4ea98d2 Mon Sep 17 00:00:00 2001
From: Michael Vrable <mvrable@cs.ucsd.edu>
Date: Sat, 19 Feb 2011 20:28:46 -0800
Subject: [PATCH] More reworking of microbenchmark handling of reads/writes and
 file layout.

---
 microbench/mixedbench.c            | 25 +++++++++++++++++++------
 microbench/run2.sh                 |  2 +-
 microbench/setup/prepare-benchmark | 12 +++++-------
 3 files changed, 25 insertions(+), 14 deletions(-)

diff --git a/microbench/mixedbench.c b/microbench/mixedbench.c
index 0447fd1..a93d5f9 100644
--- a/microbench/mixedbench.c
+++ b/microbench/mixedbench.c
@@ -92,16 +92,30 @@ void benchmark_op(struct thread_state *ts)
 
     start = now_hires();
 
-    char filename[256];
-    int n = get_random(opt_filecount);
+    /* The space of all files is partitioned evenly based on the number of
+     * threads.  Pick a file out of our particular partition. */
+    int thread_num, thread_count;
+    if (ts->thread_num >= write_threads) {
+        /* Read */
+        thread_num = ts->thread_num - write_threads;
+        thread_count = opt_threads - write_threads;
+    } else {
+        /* Write */
+        thread_num = ts->thread_num;
+        thread_count = write_threads;
+    }
+
+    int n = get_random(opt_filecount / thread_count);
+    n += thread_num * (opt_filecount / thread_count);
     int n1 = n / opt_dirsize, n2 = n % opt_dirsize;
+    char filename[256];
+    sprintf(filename, "%d/%d", n1, n2);
 
     if (ts->thread_num >= write_threads) {
         /* Read */
-        sprintf(filename, "t%d/%d/%d", ts->thread_num - write_threads, n1, n2);
         FILE *f = fopen(filename, "rb");
         if (f == NULL) {
-            perror("fopen");
+            fprintf(stderr, "fopen(%s): %m\n", filename);
             return;
         }
 
@@ -117,10 +131,9 @@ void benchmark_op(struct thread_state *ts)
         pthread_mutex_unlock(&ts->lock);
     } else {
         /* Write */
-        sprintf(filename, "t%d/%d/%d", ts->thread_num, n1, n2);
         FILE *f = fopen(filename, "wb");
         if (f == NULL) {
-            perror("fopen");
+            fprintf(stderr, "fopen(%s): %m\n", filename);
             return;
         }
 
diff --git a/microbench/run2.sh b/microbench/run2.sh
index d01a3a3..dd801c0 100755
--- a/microbench/run2.sh
+++ b/microbench/run2.sh
@@ -38,7 +38,7 @@ run_experiments() {
 for size in 128 512 1024 2048; do
     for filesize in 1024; do
         BENCH_FILESIZE=$(($filesize * 1024))
-        BENCH_FILECOUNT=$(($size * 1024 / $filesize / $BENCH_THREADS))
+        BENCH_FILECOUNT=$(($size * 1024 / $filesize))
         PREFIX=$BLUESKY_TARGET-$BENCH_WRITERATIO-${size}M-${filesize}k
 
         $HOME/bin/s3-cleanup.py
diff --git a/microbench/setup/prepare-benchmark b/microbench/setup/prepare-benchmark
index 3d2e350..eb5c7d5 100755
--- a/microbench/setup/prepare-benchmark
+++ b/microbench/setup/prepare-benchmark
@@ -31,13 +31,11 @@ mount -t nfs -o vers=3,tcp,rw,soft,intr $SERVER:/export $MNTDIR
 
 pushd $MNTDIR >/dev/null
 
-for t in $(seq 0 $(($BENCH_THREADS - 1))); do
-    for i in $(seq 0 $(($BENCH_FILECOUNT - 1))); do
-        n1=$(($i / $BENCH_DIRSIZE))
-        n2=$(($i % $BENCH_DIRSIZE))
-        mkdir -p t$t/$n1
-        dd if=/dev/zero of=t$t/$n1/$n2 bs=$BENCH_FILESIZE count=1
-    done
+mkdir $(seq 0 $(($BENCH_FILECOUNT / $BENCH_DIRSIZE)))
+for i in $(seq 0 $(($BENCH_FILECOUNT - 1))); do
+    n1=$(($i / $BENCH_DIRSIZE))
+    n2=$(($i % $BENCH_DIRSIZE))
+    dd if=/dev/zero of=$n1/$n2 bs=$BENCH_FILESIZE count=1
 done
 
 find -type f -exec sha1sum '{}' \;
-- 
2.20.1