Hi.
my midnight commander is terribly slow at vieweing files with mcview.
Opening of a file of approximately 10 megabytes takes about 30-40
seconds. This isn't related with the compression setting, %busy wait or
pool properties- I tested on various machines, it's fully reproducible.
This lag appears on files about 1.5 megs in size, and the lag time is
pretty constant. From my observation, it's the following syscall that's
blocking:
fstat(4,{ mode=p--------- ,inode=41,size=0,blksize=4096 }) = 0 (0x0)
(observed using `truss mcview maillog`)
If the file is viewed not by mcview (i.e. it is of a special type and
viewed by the special utility, or mcview is simply not used - for
example more opens same file without lag) - the file is opening fast as
always. When mcview is involved - lag appears. In the same time I've
never seen this lag on filesystems other than zfs. And the most
beautiful detail is that this lag is repeatable on multiple opens of
same file - though you can expect that it will be only first time that
would be that slow, it doesn't happen - same pause occurs on sequential
opens.
Who's issue is this ?
Can some workaround be used ?
Thanks.
Eugene.
On Tue, 10 Nov 2015 14:58+0500, Eugene M. Zheganin wrote:> my midnight commander is terribly slow at vieweing files with mcview.[snip]> Can some workaround be used ?I blame file(1), it's hopelessly slow. mcview uses file(1) to deduce if it should just display the damn file or run the file through some filter. Maybe an option in mc/mcview to disable the use of file(1) is an acceptable compromise. OTOH, I could be wrong. -- +-------------------------------+------------------------------------+ | Vennlig hilsen, | Best regards, | | Trond Endrest?l, | Trond Endrest?l, | | IT-ansvarlig, | System administrator, | | Fagskolen Innlandet, | Gj?vik Technical College, Norway, | | tlf. mob. 952 62 567, | Cellular...: +47 952 62 567, | | sentralbord 61 14 54 00. | Switchboard: +47 61 14 54 00. | +-------------------------------+------------------------------------+
Hi, On Tue, Nov 10, 2015 at 02:58:32PM +0500, Eugene M. Zheganin wrote:> Hi. > > my midnight commander is terribly slow at vieweing files with mcview. > Opening of a file of approximately 10 megabytes takes about 30-40 > seconds. This isn't related with the compression setting, %busy wait or > pool properties- I tested on various machines, it's fully reproducible. > This lag appears on files about 1.5 megs in size, and the lag time is > pretty constant. From my observation, it's the following syscall that's > blocking: > > fstat(4,{ mode=p--------- ,inode=41,size=0,blksize=4096 }) = 0 (0x0) > (observed using `truss mcview maillog`) > > If the file is viewed not by mcview (i.e. it is of a special type and > viewed by the special utility, or mcview is simply not used - for > example more opens same file without lag) - the file is opening fast as > always. When mcview is involved - lag appears. In the same time I've > never seen this lag on filesystems other than zfs.Is this happening on every ZFS FreeBSD install or just some of them? I'm running ZFS on FreeBSD 10-STABLE and I don't see this problem (even for much larger files). BR, Marko> And the most > beautiful detail is that this lag is repeatable on multiple opens of > same file - though you can expect that it will be only first time that > would be that slow, it doesn't happen - same pause occurs on sequential > opens. > > Who's issue is this ? > Can some workaround be used ? > > Thanks. > Eugene.-------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 819 bytes Desc: not available URL: <http://lists.freebsd.org/pipermail/freebsd-stable/attachments/20151110/a11e377b/attachment.bin>