Re: pkg/46529: ntfs-3g appears to be rate-limited

["Michael van Elst via gnats" <gnats-admin%NetBSD.org@localhost>]

The following reply was made to PR kern/46529; it has been noted by GNATS.

From: mlelstv%serpens.de@localhost (Michael van Elst)
To: gnats-bugs%netbsd.org@localhost
Cc: 
Subject: Re: pkg/46529: ntfs-3g appears to be rate-limited
Date: Wed, 6 May 2026 06:03:04 -0000 (UTC)

 gnats-admin%NetBSD.org@localhost ("Aaron J. Grier via gnats") writes:
 
 > raw (virtual) disk speed:
 > cratylus$ sudo dd if=/dev/ld0e of=/dev/null bs=64k count=40000
 > 40000+0 records in
 > 40000+0 records out
 > 2621440000 bytes transferred in 17.449 secs (150234397 bytes/sec)
 
 That's quite a number for reading from ld0.
 
 ld0 means, you read from the buffer cache with teensy 2kB I/O requests.
 
 The bs=64k causes 32 requests of 2kB to be issued in parallel, which
 probably also are executed in parallel for the virtual drive. A regular
 USB drive (umass) doesn't allow this, there you get sequential 2KB I/O.
 
 
 > 471026263 bytes transferred in 6.603 secs (71335190 bytes/sec)
 
 That sounds reasonable. The userland filesystem will also access
 the block device, and adds the filesystem overhead.
 
 
 To verify this, run "iostat -kx 1 ld0" while doing the test.