From: Stephen Bates <sbates@xxxxxxxxxxxx>
Allow the user to set the probability of a pvsync2 IO being high
priority. Add a new option for the pvsync2 engine called
--hipri_percentage will takes values in the range (0, 100) and use
that as a probability for setting RWF_HIPRI. The default for this
option is 100 so exisiting users of --hirpi are unaffected.
Changes since v3:
Remove unwanted #ifdefs
Changes since v2:
s/_probability/_percentage/
Changes since v1:
Use --hipri_probability rather than impacting --hipri
Correct the random number generator call
Signed-off-by: Stephen Bates <sbates@xxxxxxxxxxxx>
---
HOWTO | 5 +++++
engines/sync.c | 20 +++++++++++++++++++-
fio.1 | 4 ++++
3 files changed, 28 insertions(+), 1 deletion(-)
diff --git a/HOWTO b/HOWTO
index 2fa8fc2..a1202f1 100644
--- a/HOWTO
+++ b/HOWTO
@@ -1819,6 +1819,11 @@ caveat that when used on the command line, they must come after the
Set RWF_HIPRI on I/O, indicating to the kernel that it's of higher priority
than normal.
+.. option:: hipri_percentage : [pvsync2]
+
+ When hipri is set this determines the probability of a pvsync2 IO being high
+ priority. The default is 100%.
+
.. option:: cpuload=int : [cpuio]
Attempt to use the specified percentage of CPU cycles. This is a mandatory
diff --git a/engines/sync.c b/engines/sync.c
index e76bbbb..26b98b6 100644
--- a/engines/sync.c
+++ b/engines/sync.c
@@ -14,6 +14,7 @@
#include "../fio.h"
#include "../optgroup.h"
+#include "../lib/rand.h"
/*
* Sync engine uses engine_data to store last offset
@@ -30,12 +31,15 @@ struct syncio_data {
unsigned long long last_offset;
struct fio_file *last_file;
enum fio_ddir last_ddir;
+
+ struct frand_state rand_state;
};
#ifdef FIO_HAVE_PWRITEV2
struct psyncv2_options {
void *pad;
unsigned int hipri;
+ unsigned int hipri_percentage;
};
static struct fio_option options[] = {
@@ -49,6 +53,18 @@ static struct fio_option options[] = {
.group = FIO_OPT_G_INVALID,
},
{
+ .name = "hipri_percentage",
+ .lname = "RWF_HIPRI_PERCENTAGE",
+ .type = FIO_OPT_INT,
+ .off1 = offsetof(struct psyncv2_options, hipri_percentage),
+ .minval = 0,
+ .maxval = 100,
+ .def = "100",
+ .help = "Probabilistically set RWF_HIPRI for pwritev2/preadv2",
+ .category = FIO_OPT_C_ENGINE,
+ .group = FIO_OPT_G_INVALID,
+ },
+ {
.name = NULL,
},
};
@@ -132,7 +148,8 @@ 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 &&
+ (rand32_between(&sd->rand_state, 1, 100) <= o->hipri_percentage))
flags |= RWF_HIPRI;
iov->iov_base = io_u->xfer_buf;
@@ -363,6 +380,7 @@ static int fio_vsyncio_init(struct thread_data *td)
sd->last_offset = -1ULL;
sd->iovecs = malloc(td->o.iodepth * sizeof(struct iovec));
sd->io_us = malloc(td->o.iodepth * sizeof(struct io_u *));
+ init_rand(&sd->rand_state, 0);
td->io_ops_data = sd;
return 0;
diff --git a/fio.1 b/fio.1
index 768b209..a63c308 100644
--- a/fio.1
+++ b/fio.1
@@ -2017,6 +2017,10 @@ iodepth_batch_complete=0).
Set RWF_HIPRI on IO, indicating to the kernel that it's of
higher priority than normal.
.TP
+.BI (pvsync2)hipri_percentage
+When hipri is set this determines the probability of a pvsync2 IO being high
+priority. The default is 100%.
+.TP
.BI (net,netsplice)hostname \fR=\fPstr
The host name or IP address to use for TCP or UDP based IO.
If the job is a TCP listener or UDP reader, the hostname is not
--
1.9.1
--
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