diff --git a/chunk-format.c b/chunk-format.c
index da191e59a29d..1c3dca62e205 100644
--- a/chunk-format.c
+++ b/chunk-format.c
@@ -58,9 +58,11 @@ void add_chunk(struct chunkfile *cf,
 
 int write_chunkfile(struct chunkfile *cf, void *data)
 {
-	int i;
+	int i, result = 0;
 	uint64_t cur_offset = hashfile_total(cf->f);
 
+	trace2_region_enter("chunkfile", "write", the_repository);
+
 	/* Add the table of contents to the current offset */
 	cur_offset += (cf->chunks_nr + 1) * CHUNK_TOC_ENTRY_SIZE;
 
@@ -77,10 +79,10 @@ int write_chunkfile(struct chunkfile *cf, void *data)
 
 	for (i = 0; i < cf->chunks_nr; i++) {
 		off_t start_offset = hashfile_total(cf->f);
-		int result = cf->chunks[i].write_fn(cf->f, data);
+		result = cf->chunks[i].write_fn(cf->f, data);
 
 		if (result)
-			return result;
+			goto cleanup;
 
 		if (hashfile_total(cf->f) - start_offset != cf->chunks[i].size)
 			BUG("expected to write %"PRId64" bytes to chunk %"PRIx32", but wrote %"PRId64" instead",
@@ -88,7 +90,9 @@ int write_chunkfile(struct chunkfile *cf, void *data)
 			    hashfile_total(cf->f) - start_offset);
 	}
 
-	return 0;
+cleanup:
+	trace2_region_leave("chunkfile", "write", the_repository);
+	return result;
 }
 
 int read_table_of_contents(struct chunkfile *cf,
diff --git a/csum-file.c b/csum-file.c
index 3c26389d4914..3487d28ed7ad 100644
--- a/csum-file.c
+++ b/csum-file.c
@@ -11,19 +11,24 @@
 #include "progress.h"
 #include "csum-file.h"
 
+static void verify_buffer_or_die(struct hashfile *f,
+				 const void *buf,
+				 unsigned int count)
+{
+	ssize_t ret = read_in_full(f->check_fd, f->check_buffer, count);
+
+	if (ret < 0)
+		die_errno("%s: sha1 file read error", f->name);
+	if (ret != count)
+		die("%s: sha1 file truncated", f->name);
+	if (memcmp(buf, f->check_buffer, count))
+		die("sha1 file '%s' validation error", f->name);
+}
+
 static void flush(struct hashfile *f, const void *buf, unsigned int count)
 {
-	if (0 <= f->check_fd && count)  {
-		unsigned char check_buffer[8192];
-		ssize_t ret = read_in_full(f->check_fd, check_buffer, count);
-
-		if (ret < 0)
-			die_errno("%s: sha1 file read error", f->name);
-		if (ret != count)
-			die("%s: sha1 file truncated", f->name);
-		if (memcmp(buf, check_buffer, count))
-			die("sha1 file '%s' validation error", f->name);
-	}
+	if (0 <= f->check_fd && count)
+		verify_buffer_or_die(f, buf, count);
 
 	if (write_in_full(f->fd, buf, count) < 0) {
 		if (errno == ENOSPC)
@@ -46,6 +51,13 @@ void hashflush(struct hashfile *f)
 	}
 }
 
+static void free_hashfile(struct hashfile *f)
+{
+	free(f->buffer);
+	free(f->check_buffer);
+	free(f);
+}
+
 int finalize_hashfile(struct hashfile *f, unsigned char *result, unsigned int flags)
 {
 	int fd;
@@ -75,20 +87,20 @@ int finalize_hashfile(struct hashfile *f, unsigned char *result, unsigned int fl
 		if (close(f->check_fd))
 			die_errno("%s: sha1 file error on close", f->name);
 	}
-	free(f);
+	free_hashfile(f);
 	return fd;
 }
 
 void hashwrite(struct hashfile *f, const void *buf, unsigned int count)
 {
 	while (count) {
-		unsigned left = sizeof(f->buffer) - f->offset;
+		unsigned left = f->buffer_len - f->offset;
 		unsigned nr = count > left ? left : count;
 
 		if (f->do_crc)
 			f->crc32 = crc32(f->crc32, buf, nr);
 
-		if (nr == sizeof(f->buffer)) {
+		if (nr == f->buffer_len) {
 			/*
 			 * Flush a full batch worth of data directly
 			 * from the input, skipping the memcpy() to
@@ -114,11 +126,6 @@ void hashwrite(struct hashfile *f, const void *buf, unsigned int count)
 	}
 }
 
-struct hashfile *hashfd(int fd, const char *name)
-{
-	return hashfd_throughput(fd, name, NULL);
-}
-
 struct hashfile *hashfd_check(const char *name)
 {
 	int sink, check;
@@ -132,10 +139,14 @@ struct hashfile *hashfd_check(const char *name)
 		die_errno("unable to open '%s'", name);
 	f = hashfd(sink, name);
 	f->check_fd = check;
+	f->check_buffer = xmalloc(f->buffer_len);
+
 	return f;
 }
 
-struct hashfile *hashfd_throughput(int fd, const char *name, struct progress *tp)
+static struct hashfile *hashfd_internal(int fd, const char *name,
+					struct progress *tp,
+					size_t buffer_len)
 {
 	struct hashfile *f = xmalloc(sizeof(*f));
 	f->fd = fd;
@@ -146,9 +157,35 @@ struct hashfile *hashfd_throughput(int fd, const char *name, struct progress *tp
 	f->name = name;
 	f->do_crc = 0;
 	the_hash_algo->init_fn(&f->ctx);
+
+	f->buffer_len = buffer_len;
+	f->buffer = xmalloc(buffer_len);
+	f->check_buffer = NULL;
+
 	return f;
 }
 
+struct hashfile *hashfd(int fd, const char *name)
+{
+	/*
+	 * Since we are not going to use a progress meter to
+	 * measure the rate of data passing through this hashfile,
+	 * use a larger buffer size to reduce fsync() calls.
+	 */
+	return hashfd_internal(fd, name, NULL, 128 * 1024);
+}
+
+struct hashfile *hashfd_throughput(int fd, const char *name, struct progress *tp)
+{
+	/*
+	 * Since we are expecting to report progress of the
+	 * write into this hashfile, use a smaller buffer
+	 * size so the progress indicators arrive at a more
+	 * frequent rate.
+	 */
+	return hashfd_internal(fd, name, tp, 8 * 1024);
+}
+
 void hashfile_checkpoint(struct hashfile *f, struct hashfile_checkpoint *checkpoint)
 {
 	hashflush(f);
diff --git a/csum-file.h b/csum-file.h
index e54d53d1d0b3..3044bd19ab65 100644
--- a/csum-file.h
+++ b/csum-file.h
@@ -16,7 +16,9 @@ struct hashfile {
 	const char *name;
 	int do_crc;
 	uint32_t crc32;
-	unsigned char buffer[8192];
+	size_t buffer_len;
+	unsigned char *buffer;
+	unsigned char *check_buffer;
 };
 
 /* Checkpoint */
