From: Stephen Bates <sbates@xxxxxxxxxxxx>
Allow the user to set the probability of a pvsync2 IO being high
priority. This allows the user to investigate performance when there
is a mix of higher and lower priority IO.
Signed-off-by: Stephen Bates <sbates@xxxxxxxxxxxx>
---
HOWTO | 3 ++-
engines/sync.c | 20 +++++++++++++++++---
fio.1 | 3 ++-
3 files changed, 21 insertions(+), 5 deletions(-)
diff --git a/HOWTO b/HOWTO
index 2fa8fc2..808dea3 100644
--- a/HOWTO
+++ b/HOWTO
@@ -1817,7 +1817,8 @@ caveat that when used on the command line, they must come after the
.. option:: hipri : [pvsync2]
Set RWF_HIPRI on I/O, indicating to the kernel that it's of higher priority
- than normal.
+ than normal. This is a value is in the range [0, 100] and it
+ is probabilitistically applied to each IO.
.. option:: cpuload=int : [cpuio]
diff --git a/engines/sync.c b/engines/sync.c
index e76bbbb..33221ea 100644
--- a/engines/sync.c
+++ b/engines/sync.c
@@ -14,6 +14,9 @@
#include "../fio.h"
#include "../optgroup.h"
+#ifdef FIO_HAVE_PWRITEV2
+#include "../lib/rand.h"
+#endif
/*
* Sync engine uses engine_data to store last offset
@@ -30,6 +33,11 @@ struct syncio_data {
unsigned long long last_offset;
struct fio_file *last_file;
enum fio_ddir last_ddir;
+
+#ifdef FIO_HAVE_PWRITEV2
+ struct frand_state rand_state;
+#endif
+
};
#ifdef FIO_HAVE_PWRITEV2
@@ -42,9 +50,11 @@ static struct fio_option options[] = {
{
.name = "hipri",
.lname = "RWF_HIPRI",
- .type = FIO_OPT_STR_SET,
+ .type = FIO_OPT_INT,
.off1 = offsetof(struct psyncv2_options, hipri),
- .help = "Set RWF_HIPRI for pwritev2/preadv2",
+ .minval = 0,
+ .maxval = 100,
+ .help = "Probabilistically set RWF_HIPRI for pwritev2/preadv2",
.category = FIO_OPT_C_ENGINE,
.group = FIO_OPT_G_INVALID,
},
@@ -132,7 +142,7 @@ static int fio_pvsyncio2_queue(struct thread_data *td, struct io_u *io_u)
fio_ro_check(td, io_u);
- if (o->hipri)
+ if ((o->hipri == 100) || (rand32_between(&sd->rand_state, 0, 100) < o->hipri))
flags |= RWF_HIPRI;
iov->iov_base = io_u->xfer_buf;
@@ -364,6 +374,10 @@ static int fio_vsyncio_init(struct thread_data *td)
sd->iovecs = malloc(td->o.iodepth * sizeof(struct iovec));
sd->io_us = malloc(td->o.iodepth * sizeof(struct io_u *));
+#ifdef FIO_HAVE_PWRITEV2
+ init_rand(&sd->rand_state, 0);
+#endif
+
td->io_ops_data = sd;
return 0;
}
diff --git a/fio.1 b/fio.1
index 768b209..a25f5e4 100644
--- a/fio.1
+++ b/fio.1
@@ -2015,7 +2015,8 @@ iodepth_batch_complete=0).
.TP
.BI (pvsync2)hipri
Set RWF_HIPRI on IO, indicating to the kernel that it's of
-higher priority than normal.
+higher priority than normal. This is a value is in the range
+[0, 100] and it is probabilitistically applied to each IO.
.TP
.BI (net,netsplice)hostname \fR=\fPstr
The host name or IP address to use for TCP or UDP based IO.
--
1.9.1
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