|
From: | Paolo Bonzini |
Subject: | [Qemu-devel] Re: [PATCH] QEMU: Change default disk caching to nocache |
Date: | Thu, 20 May 2010 17:24:31 +0200 |
User-agent: | Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.9) Gecko/20100330 Fedora/3.0.4-1.fc12 Lightning/1.0b2pre Thunderbird/3.0.4 |
On 05/20/2010 11:32 AM, address@hidden wrote:
+ if (bdrv_flags & BDRV_O_NOCACHE) { + fprintf(stderr, "qemu: failed to open disk image %s as " + "nocache (O_DIRECT) retrying as write-back\n", file); + bdrv_flags &= BDRV_O_NOCACHE;
Missing ~ here.
+ bdrv_flags |= BDRV_O_CACHE_WB; + if (bdrv_open(dinfo->bdrv, file, bdrv_flags, drv)< 0) + goto error_open; + } else {
I think the retry should be done silently if no cache= option is given. That is cache=none will be the default but:
- if it is not specified and not supported by the image, fall back to writeback with no warning. However, this is just a QoI issue and can be fixed later.
- if it is specified and not supported by the image, either fall back to writeback with a warning, or fail altogether. The former would be a change in behavior, so it has to be documented somewhere if it changes.
Or maybe add BDRV_O_CACHE_WT and let the backend decide the default? Paolo
[Prev in Thread] | Current Thread | [Next in Thread] |