Messages in this thread | | | Date | Wed, 8 Jul 2015 10:40:00 -0400 (EDT) | From | Alan Stern <> | Subject | Re: [PATCH 1/1] suspend: delete sys_sync() |
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On Wed, 8 Jul 2015, Pavel Machek wrote:
> > well, that depends on what the purpose of the sync is supposed to be. > > > > If it is there to prevent users from corrupting their filesystems as a result > > of a mistake, it is insufficient. If it's there for other reasons, I'm wondering > > what those reasons are (on systems that suspend and resume reliably, because the > > original reason to put it in there was to reduce the damage from suspend/resume > > crashes). > > I put it there, and there were more reasons than "crashes" to put it > there. > > 1) crashes. > > 2) battery is quite likely to run out in suspended machine. > > 3) if someone pulls the stick and puts it in other machine, I wanted > consistent filesystem at least after journal replay.
I was going to make the same points.
From my point of view, whether to issue a sync is a tradeoff. I can't remember any time in the last several years where lack of a sync would have caused a problem for my computers, but the possibility still exists.
So on one hand, issuing the sync can help prevent a low-probability problem. On the other hand, issuing the sync takes a small amount of time (negligible for my purposes but not negligible for Len and others).
I prefer to pay a very small cost to prevent a low-probability problem. Others may not want to pay, because to them the cost is larger or the probability is lower.
_That_ is the justification for not eliminating the sync completely but making it optional.
Alan Stern
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