Kay Sievers wrote: > On Tue, Sep 2, 2008 at 13:09, Alan Jenkins <alan-jenkins@xxxxxxxxxxxxxx> wrote: > >> udev_sysfs.c device and attribute value caches are only appropriate for >> short-lived processes, like udev-event and usbid. In long lived processes >> they would fill up with stale data. >> > > Sure, the cache was never coded to be used in threaded programs. > > >> Fortunately libudev doesn't use these caches. >> > > For good reason, yeah. And it will not, at least not in its current state. > > >> But this should be made >> explicit to guard against future changes. Let's move the caches into a >> separate file, with its own initialization and cleanup functions. >> > > Wouldn't it be nicer to create a sysfs_cache object, which is passed > to all these functions? The "cheap" tools can just use NULL there, but > any possible user could have more than one instance of the cache. The > cache is really needed if you do thousand of rule compares against a > sysfs value, over and over. I guess we should start changing the stuff > to work with local vars, instead of moving the current global stuff to > a different file? > Good point. That helps make the cache usage more explicit, and it's much nicer for my purposes as well. (I had blindly converted the global cache variables to per-thread variables, without touching the callers). Ok. To keep the existing behaviour where udev_rules_get_run() reuses the cache from udev_rules_get_name(), they both need a sysfs_cache parameter. Then I have to change test-udev and udevtest as well as udevd - no point having test programs if they use different code paths. I'll see what that looks like then and resend. Thanks Alan -- To unsubscribe from this list: send the line "unsubscribe linux-hotplug" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
