From: Yann Collet Date: Wed, 5 May 2021 16:03:11 +0000 (-0700) Subject: updated documentation regarding minimum job size X-Git-Tag: v1.5.0^2~37 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=455fd1a067cd1cac7c33ee58b886a3a365a1dd18;p=thirdparty%2Fzstd.git updated documentation regarding minimum job size --- diff --git a/lib/zstd.h b/lib/zstd.h index 111516d05..8f0ba268d 100644 --- a/lib/zstd.h +++ b/lib/zstd.h @@ -402,7 +402,7 @@ typedef enum { ZSTD_c_jobSize=401, /* Size of a compression job. This value is enforced only when nbWorkers >= 1. * Each compression job is completed in parallel, so this value can indirectly impact the nb of active threads. * 0 means default, which is dynamically determined based on compression parameters. - * Job size must be a minimum of overlap size, or 1 MB, whichever is largest. + * Job size must be a minimum of overlap size, or ZSTDMT_JOBSIZE_MIN (= 512 KB), whichever is largest. * The minimum size is automatically and transparently enforced. */ ZSTD_c_overlapLog=402, /* Control the overlap size, as a fraction of window size. * The overlap size is an amount of data reloaded from previous job at the beginning of a new job. diff --git a/programs/zstd.1 b/programs/zstd.1 index 1b7c88d8a..b68679893 100644 --- a/programs/zstd.1 +++ b/programs/zstd.1 @@ -1,5 +1,5 @@ . -.TH "ZSTD" "1" "March 2021" "zstd 1.4.9" "User Commands" +.TH "ZSTD" "1" "May 2021" "zstd 1.4.10" "User Commands" . .SH "NAME" \fBzstd\fR \- zstd, zstdmt, unzstd, zstdcat \- Compress or decompress \.zst files @@ -343,6 +343,9 @@ set process priority to real\-time . .SH "ADVANCED COMPRESSION OPTIONS" . +.SS "\-B#:" +Select the size of each compression job\. This parameter is only available when multi\-threading is enabled\. Each compression job is run in parallel, so this value indirectly impacts the nb of active threads\. Default job size varies depending on compression level (generally \fB4 * windowSize\fR)\. \fB\-B#\fR makes it possible to manually select a custom size\. Note that job size must respect a minimum value which is enforced transparently\. This minimum is either 512 KB, or \fBoverlapSize\fR, whichever is largest\. Different job sizes will lead to (slightly) different compressed frames\. +. .SS "\-\-zstd[=options]:" \fBzstd\fR provides 22 predefined compression levels\. The selected or default predefined compression level can be changed with advanced compression options\. The \fIoptions\fR are provided as a comma\-separated list\. You may specify only the options you want to change and the rest will be taken from the selected or default compression level\. The list of available \fIoptions\fR: . @@ -481,9 +484,6 @@ The following parameters sets advanced compression options to something similar .P \fB\-\-zstd\fR=wlog=23,clog=23,hlog=22,slog=6,mml=3,tlen=48,strat=6 . -.SS "\-B#:" -Select the size of each compression job\. This parameter is available only when multi\-threading is enabled\. Default value is \fB4 * windowSize\fR, which means it varies depending on compression level\. \fB\-B#\fR makes it possible to select a custom value\. Note that job size must respect a minimum value which is enforced transparently\. This minimum is either 1 MB, or \fBoverlapSize\fR, whichever is largest\. -. .SH "BUGS" Report bugs at: https://github\.com/facebook/zstd/issues . diff --git a/programs/zstd.1.md b/programs/zstd.1.md index 0b259b668..1220a8140 100644 --- a/programs/zstd.1.md +++ b/programs/zstd.1.md @@ -423,6 +423,16 @@ BENCHMARK ADVANCED COMPRESSION OPTIONS ---------------------------- +### -B#: +Select the size of each compression job. +This parameter is only available when multi-threading is enabled. +Each compression job is run in parallel, so this value indirectly impacts the nb of active threads. +Default job size varies depending on compression level (generally `4 * windowSize`). +`-B#` makes it possible to manually select a custom size. +Note that job size must respect a minimum value which is enforced transparently. +This minimum is either 512 KB, or `overlapSize`, whichever is largest. +Different job sizes will lead to (slightly) different compressed frames. + ### --zstd[=options]: `zstd` provides 22 predefined compression levels. The selected or default predefined compression level can be changed with @@ -566,13 +576,6 @@ similar to predefined level 19 for files bigger than 256 KB: `--zstd`=wlog=23,clog=23,hlog=22,slog=6,mml=3,tlen=48,strat=6 -### -B#: -Select the size of each compression job. -This parameter is available only when multi-threading is enabled. -Default value is `4 * windowSize`, which means it varies depending on compression level. -`-B#` makes it possible to select a custom value. -Note that job size must respect a minimum value which is enforced transparently. -This minimum is either 1 MB, or `overlapSize`, whichever is largest. BUGS ---- diff --git a/programs/zstdgrep.1 b/programs/zstdgrep.1 index 0f37bea93..e3fd95ef2 100644 --- a/programs/zstdgrep.1 +++ b/programs/zstdgrep.1 @@ -1,5 +1,5 @@ . -.TH "ZSTDGREP" "1" "March 2021" "zstd 1.4.9" "User Commands" +.TH "ZSTDGREP" "1" "May 2021" "zstd 1.4.10" "User Commands" . .SH "NAME" \fBzstdgrep\fR \- print lines matching a pattern in zstandard\-compressed files diff --git a/programs/zstdless.1 b/programs/zstdless.1 index 0ade28e93..e9d01acc9 100644 --- a/programs/zstdless.1 +++ b/programs/zstdless.1 @@ -1,5 +1,5 @@ . -.TH "ZSTDLESS" "1" "March 2021" "zstd 1.4.9" "User Commands" +.TH "ZSTDLESS" "1" "May 2021" "zstd 1.4.10" "User Commands" . .SH "NAME" \fBzstdless\fR \- view zstandard\-compressed files