Re: [dm-devel] Re: [multipath 1/1] cache sysfs_devices

[Guido Guenther <agx sigxcpu org>]

On Tue, Jul 24, 2007 at 08:35:16AM +0200, Hannes Reinecke wrote:
> Guido Guenther wrote:
> > I give up on git-send-email - it always fools me. Nevertheless this one
> > fixes the described bug of paths coming back as different block
> > devices:
> > 
> > Keep a list of sysfs devices for sysfs_device_get() so uev_trigger() can look
> > up the necessary information for proper path removal in case of a 'remove'
> > uevent - the sysfs files in the filesystem might be long gone at this point.
> > 
> > This also plugs a memory leak where we'd malloc space for the same sysfs device
> > over and over again for every processed uevent.
> > 
> Hmm. But now we're running into the opposite trap: memory for a block device once
> existing will never be freed. So over time we're likely to become a memory hog.
So far we did not free any memory _and_ we would end up allocating memory
for every path that comes back up over and over again.

> Better it would be to remove the sysfs device from the cache once we're done
> with it.
Fair enough, we won't need the information then anyway.
Thanks,
 -- Guido