X-Git-Url: https://git.kernel.dk/?a=blobdiff_plain;f=fio.1;h=481193254832befdd285394d6424c209b8805989;hb=7914c6147adaf3ef32804519ced850168fff1711;hp=cdd105d7b3ea1496b828c4e3ce0a6d14aae03b21;hpb=f0ed01ed095cf1ca7c1945a5a0267e8f73b7b4a9;p=fio.git diff --git a/fio.1 b/fio.1 index cdd105d7..48119325 100644 --- a/fio.1 +++ b/fio.1 @@ -1462,9 +1462,31 @@ starting I/O if the platform and file type support it. Defaults to true. This will be ignored if \fBpre_read\fR is also specified for the same job. .TP -.BI sync \fR=\fPbool -Use synchronous I/O for buffered writes. For the majority of I/O engines, -this means using O_SYNC. Default: false. +.BI sync \fR=\fPstr +Whether, and what type, of synchronous I/O to use for writes. The allowed +values are: +.RS +.RS +.TP +.B none +Do not use synchronous IO, the default. +.TP +.B 0 +Same as \fBnone\fR. +.TP +.B sync +Use synchronous file IO. For the majority of I/O engines, +this means using O_SYNC. +.TP +.B 1 +Same as \fBsync\fR. +.TP +.B dsync +Use synchronous data IO. For the majority of I/O engines, +this means using O_DSYNC. +.PD +.RE +.RE .TP .BI iomem \fR=\fPstr "\fR,\fP mem" \fR=\fPstr Fio can use various types of memory as the I/O unit buffer. The allowed @@ -1561,7 +1583,8 @@ if \fBsize\fR is set to 20GiB and \fBio_size\fR is set to 5GiB, fio will perform I/O within the first 20GiB but exit when 5GiB have been done. The opposite is also possible \-\- if \fBsize\fR is set to 20GiB, and \fBio_size\fR is set to 40GiB, then fio will do 40GiB of I/O within -the 0..20GiB region. +the 0..20GiB region. Value can be set as percentage: \fBio_size\fR=N%. +In this case \fBio_size\fR multiplies \fBsize\fR= value. .TP .BI filesize \fR=\fPirange(int) Individual file sizes. May be a range, in which case fio will select sizes @@ -1674,11 +1697,6 @@ to get desired CPU usage, as the cpuload only loads a single CPU at the desired rate. A job never finishes unless there is at least one non-cpuio job. .TP -.B guasi -The GUASI I/O engine is the Generic Userspace Asynchronous Syscall -Interface approach to async I/O. See \fIhttp://www.xmailserver.org/guasi-lib.html\fR -for more info on GUASI. -.TP .B rdma The RDMA I/O engine supports both RDMA memory semantics (RDMA_WRITE/RDMA_READ) and channel semantics (Send/Recv) for the @@ -2219,7 +2237,7 @@ has a bit of extra overhead, especially for lower queue depth I/O where it can increase latencies. The benefit is that fio can manage submission rates independently of the device completion rates. This avoids skewed latency reporting if I/O gets backed up on the device side (the coordinated omission -problem). +problem). Note that this option cannot reliably be used with async IO engines. .SS "I/O rate" .TP .BI thinktime \fR=\fPtime @@ -2549,27 +2567,25 @@ The ID of the flow. If not specified, it defaults to being a global flow. See \fBflow\fR. .TP .BI flow \fR=\fPint -Weight in token-based flow control. If this value is used, then there is -a 'flow counter' which is used to regulate the proportion of activity between -two or more jobs. Fio attempts to keep this flow counter near zero. The -\fBflow\fR parameter stands for how much should be added or subtracted to the -flow counter on each iteration of the main I/O loop. That is, if one job has -`flow=8' and another job has `flow=\-1', then there will be a roughly 1:8 -ratio in how much one runs vs the other. -.TP -.BI flow_watermark \fR=\fPint -The maximum value that the absolute value of the flow counter is allowed to -reach before the job must wait for a lower value of the counter. +Weight in token-based flow control. If this value is used, +then fio regulates the activity between two or more jobs +sharing the same flow_id. +Fio attempts to keep each job activity proportional to other jobs' activities +in the same flow_id group, with respect to requested weight per job. +That is, if one job has `flow=3', another job has `flow=2' +and another with `flow=1`, then there will be a roughly 3:2:1 ratio +in how much one runs vs the others. .TP .BI flow_sleep \fR=\fPint -The period of time, in microseconds, to wait after the flow watermark has -been exceeded before retrying operations. +The period of time, in microseconds, to wait after the flow counter +has exceeded its proportion before retrying operations. .TP .BI stonewall "\fR,\fB wait_for_previous" Wait for preceding jobs in the job file to exit, before starting this one. Can be used to insert serialization points in the job file. A stone wall also implies starting a new reporting group, see -\fBgroup_reporting\fR. +\fBgroup_reporting\fR. Optionally you can use `stonewall=0` to disable or +`stonewall=1` to enable it. .TP .BI exitall By default, fio will continue running all other jobs when one job finishes. @@ -2577,15 +2593,27 @@ Sometimes this is not the desired action. Setting \fBexitall\fR will instead make fio terminate all jobs in the same group, as soon as one job of that group finishes. .TP -.BI exit_what +.BI exit_what \fR=\fPstr By default, fio will continue running all other jobs when one job finishes. -Sometimes this is not the desired action. Setting \fBexit_all\fR will instead +Sometimes this is not the desired action. Setting \fBexitall\fR will instead make fio terminate all jobs in the same group. The option \fBexit_what\fR -allows to control which jobs get terminated when \fBexitall\fR is enabled. The -default is \fBgroup\fR and does not change the behaviour of \fBexitall\fR. The -setting \fBall\fR terminates all jobs. The setting \fBstonewall\fR terminates -all currently running jobs across all groups and continues execution with the -next stonewalled group. +allows you to control which jobs get terminated when \fBexitall\fR is enabled. +The default value is \fBgroup\fR. +The allowed values are: +.RS +.RS +.TP +.B all +terminates all jobs. +.TP +.B group +is the default and does not change the behaviour of \fBexitall\fR. +.TP +.B stonewall +terminates all currently running jobs across all groups and continues +execution with the next stonewalled group. +.RE +.RE .TP .BI exec_prerun \fR=\fPstr Before running this job, issue the command specified through