From 82787c6f689d869ad349df83ec3f58702afe00fe Mon Sep 17 00:00:00 2001 From: Ian Jackson Date: Mon, 2 Mar 2009 11:21:51 +0000 Subject: [PATCH] Override default cache mode for disk images to write-back Upstream qemu changed the default cache mode to write-through (ie, O_DSYNC) which is much slower. We do not need this as we have explicit control of cacheing with the IDE cache control commands. Original patch by Yang Zhang modified by Ian Jackson. Signed-off-by: Yang Zhang Signed-off-by: Ian Jackson --- xenstore.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/xenstore.c b/xenstore.c index 6bfcdbbb..928e950c 100644 --- a/xenstore.c +++ b/xenstore.c @@ -472,7 +472,7 @@ void xenstore_parse_domain_config(int hvm_domid) #ifdef CONFIG_STUBDOM if (pasprintf(&danger_buf, "%s/device/vbd/%s", danger_path, e_danger[i]) == -1) continue; - if (bdrv_open2(bs, danger_buf, 0 /* snapshot */, &bdrv_vbd) == 0) { + if (bdrv_open2(bs, danger_buf, BDRV_O_CACHE_WB /* snapshot and write-back */, &bdrv_vbd) == 0) { pstrcpy(bs->filename, sizeof(bs->filename), params); } else #endif @@ -498,7 +498,7 @@ void xenstore_parse_domain_config(int hvm_domid) } } pstrcpy(bs->filename, sizeof(bs->filename), params); - if (bdrv_open2(bs, params, 0 /* snapshot */, format) < 0) + if (bdrv_open2(bs, params, BDRV_O_CACHE_WB /* snapshot and write-back */, format) < 0) fprintf(stderr, "qemu: could not open vbd '%s' or hard disk image '%s' (drv '%s' format '%s')\n", buf, params, drv ? drv : "?", format ? format->format_name : "0"); } -- 2.39.5