X-Git-Url: https://git.kernel.dk/?p=fio.git;a=blobdiff_plain;f=HOWTO;h=812440648815d97af8f89b40a20efc35695b967a;hp=4fd4da1471758c14808f1d545d33b2a267557b42;hb=4cbe3909942e913f3a71113bf4036824fcb54953;hpb=247ef2aaf28a18abdf49d294ecbffd497ee440e6 diff --git a/HOWTO b/HOWTO index 4fd4da14..81244064 100644 --- a/HOWTO +++ b/HOWTO @@ -1805,6 +1805,11 @@ I/O engine **pvsync2** Basic :manpage:`preadv2(2)` or :manpage:`pwritev2(2)` I/O. + **io_uring** + Fast Linux native asynchronous I/O. Supports async IO + for both direct and buffered IO. + This engine defines engine specific options. + **libaio** Linux native asynchronous I/O. Note that Linux may only support queued behavior with non-buffered I/O (set ``direct=1`` or @@ -2002,6 +2007,35 @@ In addition, there are some parameters which are only valid when a specific with the caveat that when used on the command line, they must come after the :option:`ioengine` that defines them is selected. +.. option:: hipri : [io_uring] + + If this option is set, fio will attempt to use polled IO completions. + Normal IO completions generate interrupts to signal the completion of + IO, polled completions do not. Hence they are require active reaping + by the application. The benefits are more efficient IO for high IOPS + scenarios, and lower latencies for low queue depth IO. + +.. option:: fixedbufs : [io_uring] + + If fio is asked to do direct IO, then Linux will map pages for each + IO call, and release them when IO is done. If this option is set, the + pages are pre-mapped before IO is started. This eliminates the need to + map and release for each IO. This is more efficient, and reduces the + IO latency as well. + +.. option:: sqthread_poll : [io_uring] + + Normally fio will submit IO by issuing a system call to notify the + kernel of available items in the SQ ring. If this option is set, the + act of submitting IO will be done by a polling thread in the kernel. + This frees up cycles for fio, at the cost of using more CPU in the + system. + +.. option:: sqthread_poll_cpu : [io_uring] + + When :option:`sqthread_poll` is set, this option provides a way to + define which CPU should be used for the polling thread. + .. option:: userspace_reap : [libaio] Normally, with the libaio engine in use, fio will use the @@ -3693,7 +3727,8 @@ is one long line of values, such as:: 2;card0;0;0;7139336;121836;60004;1;10109;27.932460;116.933948;220;126861;3495.446807;1085.368601;226;126864;3523.635629;1089.012448;24063;99944;50.275485%;59818.274627;5540.657370;7155060;122104;60004;1;8338;29.086342;117.839068;388;128077;5032.488518;1234.785715;391;128085;5061.839412;1236.909129;23436;100928;50.287926%;59964.832030;5644.844189;14.595833%;19.394167%;123706;0;7313;0.1%;0.1%;0.1%;0.1%;0.1%;0.1%;100.0%;0.00%;0.00%;0.00%;0.00%;0.00%;0.00%;0.01%;0.02%;0.05%;0.16%;6.04%;40.40%;52.68%;0.64%;0.01%;0.00%;0.01%;0.00%;0.00%;0.00%;0.00%;0.00% A description of this job goes here. -The job description (if provided) follows on a second line. +The job description (if provided) follows on a second line for terse v2. +It appears on the same line for other terse versions. To enable terse output, use the :option:`--minimal` or :option:`--output-format`\=terse command line options. The @@ -3778,6 +3813,11 @@ minimal output v3, separated by semicolons:: terse_version_3;fio_version;jobname;groupid;error;read_kb;read_bandwidth;read_iops;read_runtime_ms;read_slat_min;read_slat_max;read_slat_mean;read_slat_dev;read_clat_min;read_clat_max;read_clat_mean;read_clat_dev;read_clat_pct01;read_clat_pct02;read_clat_pct03;read_clat_pct04;read_clat_pct05;read_clat_pct06;read_clat_pct07;read_clat_pct08;read_clat_pct09;read_clat_pct10;read_clat_pct11;read_clat_pct12;read_clat_pct13;read_clat_pct14;read_clat_pct15;read_clat_pct16;read_clat_pct17;read_clat_pct18;read_clat_pct19;read_clat_pct20;read_tlat_min;read_lat_max;read_lat_mean;read_lat_dev;read_bw_min;read_bw_max;read_bw_agg_pct;read_bw_mean;read_bw_dev;write_kb;write_bandwidth;write_iops;write_runtime_ms;write_slat_min;write_slat_max;write_slat_mean;write_slat_dev;write_clat_min;write_clat_max;write_clat_mean;write_clat_dev;write_clat_pct01;write_clat_pct02;write_clat_pct03;write_clat_pct04;write_clat_pct05;write_clat_pct06;write_clat_pct07;write_clat_pct08;write_clat_pct09;write_clat_pct10;write_clat_pct11;write_clat_pct12;write_clat_pct13;write_clat_pct14;write_clat_pct15;write_clat_pct16;write_clat_pct17;write_clat_pct18;write_clat_pct19;write_clat_pct20;write_tlat_min;write_lat_max;write_lat_mean;write_lat_dev;write_bw_min;write_bw_max;write_bw_agg_pct;write_bw_mean;write_bw_dev;cpu_user;cpu_sys;cpu_csw;cpu_mjf;cpu_minf;iodepth_1;iodepth_2;iodepth_4;iodepth_8;iodepth_16;iodepth_32;iodepth_64;lat_2us;lat_4us;lat_10us;lat_20us;lat_50us;lat_100us;lat_250us;lat_500us;lat_750us;lat_1000us;lat_2ms;lat_4ms;lat_10ms;lat_20ms;lat_50ms;lat_100ms;lat_250ms;lat_500ms;lat_750ms;lat_1000ms;lat_2000ms;lat_over_2000ms;disk_name;disk_read_iops;disk_write_iops;disk_read_merges;disk_write_merges;disk_read_ticks;write_ticks;disk_queue_time;disk_util +In client/server mode terse output differs from what appears when jobs are run +locally. Disk utilization data is omitted from the standard terse output and +for v3 and later appears on its own separate line at the end of each terse +reporting cycle. + JSON output ------------ @@ -4056,6 +4096,7 @@ is recorded. Each *data direction* seen within the window period will aggregate its values in a separate row. Further, when using windowed logging the *block size* and *offset* entries will always contain 0. + Client/Server ------------- @@ -4143,3 +4184,6 @@ containing two hostnames ``h1`` and ``h2`` with IP addresses 192.168.10.120 and /mnt/nfs/fio/192.168.10.120.fileio.tmp /mnt/nfs/fio/192.168.10.121.fileio.tmp + +Terse output in client/server mode will differ slightly from what is produced +when fio is run in stand-alone mode. See the terse output section for details.