Re: [Qemu-devel] [PATCH 1/4] qemu-io: New option "-a" to aio_read and aio_write

[Fam Zheng <famz@redhat.com>]

On Wed, 01/29 16:58, Paolo Bonzini wrote:
> Il 29/01/2014 09:40, Fam Zheng ha scritto:
> >This option will enable accounting of aio requests.
> >
> >Signed-off-by: Fam Zheng <famz@redhat.com>
> >---
> > qemu-io-cmds.c | 35 +++++++++++++++++++++++++++++++----
> > 1 file changed, 31 insertions(+), 4 deletions(-)
> >
> >diff --git a/qemu-io-cmds.c b/qemu-io-cmds.c
> >index f1de24c..d6e20e6 100644
> >--- a/qemu-io-cmds.c
> >+++ b/qemu-io-cmds.c
> >@@ -1346,6 +1346,7 @@ out:
> > }
> >
> > struct aio_ctx {
> >+    BlockDriverState *bs;
> >     QEMUIOVector qiov;
> >     int64_t offset;
> >     char *buf;
> >@@ -1353,6 +1354,8 @@ struct aio_ctx {
> >     int vflag;
> >     int Cflag;
> >     int Pflag;
> >+    int aflag;
> >+    BlockAcctCookie acct;
> >     int pattern;
> >     struct timeval t1;
> > };
> >@@ -1370,6 +1373,10 @@ static void aio_write_done(void *opaque, int ret)
> >         goto out;
> >     }
> >
> >+    if (ctx->aflag) {
> >+        bdrv_acct_done(ctx->bs, &ctx->acct);
> >+    }
> >+
> >     if (ctx->qflag) {
> >         goto out;
> >     }
> >@@ -1407,6 +1414,10 @@ static void aio_read_done(void *opaque, int ret)
> >         g_free(cmp_buf);
> >     }
> >
> >+    if (ctx->aflag) {
> >+        bdrv_acct_done(ctx->bs, &ctx->acct);
> >+    }
> >+
> >     if (ctx->qflag) {
> >         goto out;
> >     }
> >@@ -1442,6 +1453,7 @@ static void aio_read_help(void)
> > " -P, -- use a pattern to verify read data\n"
> > " -v, -- dump buffer to standard output\n"
> > " -q, -- quiet mode, do not show I/O statistics\n"
> >+" -a, -- account IO\n"
> > "\n");
> > }
> >
> >@@ -1452,7 +1464,7 @@ static const cmdinfo_t aio_read_cmd = {
> >     .cfunc      = aio_read_f,
> >     .argmin     = 2,
> >     .argmax     = -1,
> >-    .args       = "[-Cqv] [-P pattern ] off len [len..]",
> >+    .args       = "[-Cqva] [-P pattern ] off len [len..]",
> >     .oneline    = "asynchronously reads a number of bytes",
> >     .help       = aio_read_help,
> > };
> >@@ -1462,7 +1474,8 @@ static int aio_read_f(BlockDriverState *bs, int argc, char **argv)
> >     int nr_iov, c;
> >     struct aio_ctx *ctx = g_new0(struct aio_ctx, 1);
> >
> >-    while ((c = getopt(argc, argv, "CP:qv")) != EOF) {
> >+    ctx->bs = bs;
> >+    while ((c = getopt(argc, argv, "CP:qva")) != EOF) {
> >         switch (c) {
> >         case 'C':
> >             ctx->Cflag = 1;
> >@@ -1481,6 +1494,9 @@ static int aio_read_f(BlockDriverState *bs, int argc, char **argv)
> >         case 'v':
> >             ctx->vflag = 1;
> >             break;
> >+        case 'a':
> >+            ctx->aflag = 1;
> >+            break;
> >         default:
> >             g_free(ctx);
> >             return qemuio_command_usage(&aio_read_cmd);
> >@@ -1515,6 +1531,9 @@ static int aio_read_f(BlockDriverState *bs, int argc, char **argv)
> >     }
> >
> >     gettimeofday(&ctx->t1, NULL);
> >+    if (ctx->aflag) {
> >+        bdrv_acct_start(bs, &ctx->acct, ctx->qiov.size, BDRV_ACCT_READ);
> >+    }
> >     bdrv_aio_readv(bs, ctx->offset >> 9, &ctx->qiov,
> >                    ctx->qiov.size >> 9, aio_read_done, ctx);
> >     return 0;
> >@@ -1537,6 +1556,7 @@ static void aio_write_help(void)
> > " -P, -- use different pattern to fill file\n"
> > " -C, -- report statistics in a machine parsable format\n"
> > " -q, -- quiet mode, do not show I/O statistics\n"
> >+" -a, -- account IO\n"
> > "\n");
> > }
> >
> >@@ -1547,7 +1567,7 @@ static const cmdinfo_t aio_write_cmd = {
> >     .cfunc      = aio_write_f,
> >     .argmin     = 2,
> >     .argmax     = -1,
> >-    .args       = "[-Cq] [-P pattern ] off len [len..]",
> >+    .args       = "[-Cqa] [-P pattern ] off len [len..]",
> >     .oneline    = "asynchronously writes a number of bytes",
> >     .help       = aio_write_help,
> > };
> >@@ -1558,7 +1578,8 @@ static int aio_write_f(BlockDriverState *bs, int argc, char **argv)
> >     int pattern = 0xcd;
> >     struct aio_ctx *ctx = g_new0(struct aio_ctx, 1);
> >
> >-    while ((c = getopt(argc, argv, "CqP:")) != EOF) {
> >+    ctx->bs = bs;
> >+    while ((c = getopt(argc, argv, "CqP:a")) != EOF) {
> >         switch (c) {
> >         case 'C':
> >             ctx->Cflag = 1;
> >@@ -1573,6 +1594,9 @@ static int aio_write_f(BlockDriverState *bs, int argc, char **argv)
> >                 return 0;
> >             }
> >             break;
> >+        case 'a':
> >+            ctx->aflag = 1;
> >+            break;
> >         default:
> >             g_free(ctx);
> >             return qemuio_command_usage(&aio_write_cmd);
> >@@ -1607,6 +1631,9 @@ static int aio_write_f(BlockDriverState *bs, int argc, char **argv)
> >     }
> >
> >     gettimeofday(&ctx->t1, NULL);
> >+    if (ctx->aflag) {
> >+        bdrv_acct_start(bs, &ctx->acct, ctx->qiov.size, BDRV_ACCT_WRITE);
> >+    }
> >     bdrv_aio_writev(bs, ctx->offset >> 9, &ctx->qiov,
> >                     ctx->qiov.size >> 9, aio_write_done, ctx);
> >     return 0;
> >
> 
> Why can't it be enabled unconditionally?
> 

So the default behavior is unchanged.

Fam