From 2e266ba6f1235c9201c95026714f8b1e3b99f344 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Mon, 14 Sep 2009 08:56:53 +0200 Subject: [PATCH] Add a bit of huge page documentation Signed-off-by: Jens Axboe --- fio.1 | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/fio.1 b/fio.1 index 10b1768c..f216b4cb 100644 --- a/fio.1 +++ b/fio.1 @@ -515,7 +515,11 @@ Same as \fBmmap\fR, but use huge files as backing. The amount of memory allocated is the maximum allowed \fBblocksize\fR for the job multiplied by \fBiodepth\fR. For \fBshmhuge\fR or \fBmmaphuge\fR to work, the system must have free huge pages allocated. \fBmmaphuge\fR also needs to -have hugetlbfs mounted, and \fIfile\fR must point there. +have hugetlbfs mounted, and \fIfile\fR must point there. At least on Linux, +huge pages must be manually allocated. See \fB/proc/sys/vm/nr_hugehages\fR +and the documentation for that. Normally you just need to echo an appropriate +number, eg echoing 8 will ensure that the OS has 8 huge pages ready for +use. .RE .TP .BI iomem_align \fR=\fPint -- 2.25.1