Date: Sun, 28 Sep 2008 00:52:04 +0200 (CEST) From: Juergen Lock <nox@jelal.kn-bremen.de> To: anthony@codemonkey.ws Cc: freebsd-emulation@freebsd.org, qemu-devel@nongnu.org Subject: Re: [Qemu-devel] Re: qemu svn r5281 on FreeBSD - slow usb, vmwarevga, screen updates... (now updated to r5313) Message-ID: <200809272252.m8RMq4fu057049@saturn.kn-bremen.de> In-Reply-To: <48DE5256.5000101@codemonkey.ws> References: <20080921204025.GA81055@saturn.kn-bremen.de> <cd6b4a5b0809230639x27e94477k315796c2cfb650f2@mail.gmail.com> <200809242210.m8OMAcSZ021572@saturn.kn-bremen.de> <cd6b4a5b0809241954p159dd86u17fdc2a485008e7d@mail.gmail.com> <48DCF9FC.2070708@codemonkey.ws> <20080926220445.GA13099@saturn.kn-bremen.de>
next in thread | previous in thread | raw e-mail | index | archive | help
In article <48DE5256.5000101@codemonkey.ws> you write:
>[...]
>>> The one thing that really tripped me up with the whole aio kld-module
>>> thing. Perhaps we should detect the presence of the module at run time and
>>> disable aio? I assume kldload can only be run as root?
>>>
>>
>> Yes. Atm the ports print a warning when aio is not loaded:
>>
>
>Yeah, I don't think this is enough. I'd rather see AIO be disabled when
>modfind("aio") is not available (printing a warning along with that
>would be fine). A non-privileged user cannot load the aio module so
>it's not very useful to tell them to load it.
OK so how about the following? (only tested with a raw image, but if
the way its disabled for OpenBSD works for all of them this should as well.)
Oh and am I right qemu-img doesn't use aio? If it actually does we may
want to add the same check there instead of just disabling it. (I kept it
enabled for qemu-nbd since thats not built on FreeBSD anyway.)
Index: qemu/block.h
@@ -50,10 +50,9 @@
#define BDRV_O_DIRECT 0x0020
#define BDRV_O_AUTOGROW 0x0040 /* Allow backing file to extend when writing past end of file */
-void bdrv_info(void);
+void bdrv_init(int emulate_aio);
void bdrv_info_stats(void);
-void bdrv_init(void);
BlockDriver *bdrv_find_format(const char *format_name);
int bdrv_create(BlockDriver *drv,
const char *filename, int64_t size_in_sectors,
Index: qemu/block.c
@@ -177,9 +177,9 @@
}
-static void bdrv_register(BlockDriver *bdrv)
+static void bdrv_register(BlockDriver *bdrv, int emulate_aio)
{
- if (!bdrv->bdrv_aio_read) {
+ if (!bdrv->bdrv_aio_read || emulate_aio) {
/* add AIO emulation layer */
bdrv->bdrv_aio_read = bdrv_aio_read_em;
bdrv->bdrv_aio_write = bdrv_aio_write_em;
@@ -1374,23 +1374,23 @@
return async_ret;
}
-void bdrv_init(void)
+void bdrv_init(int emulate_aio)
{
- bdrv_register(&bdrv_raw);
- bdrv_register(&bdrv_host_device);
+ bdrv_register(&bdrv_raw, emulate_aio);
+ bdrv_register(&bdrv_host_device, 0);
#ifndef _WIN32
- bdrv_register(&bdrv_cow);
+ bdrv_register(&bdrv_cow, 0);
#endif
- bdrv_register(&bdrv_qcow);
- bdrv_register(&bdrv_vmdk);
- bdrv_register(&bdrv_cloop);
- bdrv_register(&bdrv_dmg);
- bdrv_register(&bdrv_bochs);
- bdrv_register(&bdrv_vpc);
- bdrv_register(&bdrv_vvfat);
- bdrv_register(&bdrv_qcow2);
- bdrv_register(&bdrv_parallels);
- bdrv_register(&bdrv_nbd);
+ bdrv_register(&bdrv_qcow, 0);
+ bdrv_register(&bdrv_vmdk, 0);
+ bdrv_register(&bdrv_cloop, 0);
+ bdrv_register(&bdrv_dmg, 0);
+ bdrv_register(&bdrv_bochs, 0);
+ bdrv_register(&bdrv_vpc, 0);
+ bdrv_register(&bdrv_vvfat, 0);
+ bdrv_register(&bdrv_qcow2, 0);
+ bdrv_register(&bdrv_parallels, 0);
+ bdrv_register(&bdrv_nbd, 0);
}
void *qemu_aio_get(BlockDriverState *bs, BlockDriverCompletionFunc *cb,
Index: qemu/vl.c
@@ -8609,6 +8609,7 @@
int tb_size;
const char *pid_file = NULL;
VLANState *vlan;
+ int emulate_aio = 0;
LIST_INIT (&vm_change_state_head);
#ifndef _WIN32
@@ -8681,6 +8682,13 @@
tb_size = 0;
+#ifdef __FreeBSD__
+ if (modfind("aio") == -1) {
+ emulate_aio = 1;
+ fprintf(stderr, "warning: aio not (kld)loaded, disabling (may slow down on disk IO\n");
+ }
+#endif
+
optind = 1;
for(;;) {
if (optind >= argc)
@@ -9415,7 +9423,7 @@
/* init the dynamic translator */
cpu_exec_init_all(tb_size * 1024 * 1024);
- bdrv_init();
+ bdrv_init(emulate_aio);
/* we always create the cdrom drive, even if no disk is there */
Index: qemu/qemu-img.c
@@ -733,7 +733,7 @@
{
const char *cmd;
- bdrv_init();
+ bdrv_init(1);
if (argc < 2)
help();
cmd = argv[1];
Index: qemu/qemu-nbd.c
@@ -326,7 +326,7 @@
return 0;
}
- bdrv_init();
+ bdrv_init(0);
bs = bdrv_new("hda");
if (bs == NULL)
Signed-off-by: Juergen Lock <nox@jelal.kn-bremen.de>
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200809272252.m8RMq4fu057049>