From a0679ce5a9652f760e93ae083291f557ded60758 Mon Sep 17 00:00:00 2001 From: Stephen Bates Date: Thu, 27 Jul 2017 14:02:15 -0600 Subject: [PATCH] pvsync2: Add hipri_percentage option 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 Signed-off-by: Jens Axboe --- HOWTO | 5 +++++ engines/sync.c | 20 +++++++++++++++++++- fio.1 | 4 ++++ 3 files changed, 28 insertions(+), 1 deletion(-) diff --git a/HOWTO b/HOWTO index fe5c3cb1..caf6591a 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 e76bbbb4..26b98b60 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[] = { @@ -48,6 +52,18 @@ static struct fio_option options[] = { .category = FIO_OPT_C_ENGINE, .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 f86b7fdf..a5ec1999 100644 --- a/fio.1 +++ b/fio.1 @@ -2018,6 +2018,10 @@ 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 -- 2.25.1