Messages in this thread | | | Date | Mon, 3 Jan 2022 10:54:50 +0100 | From | Greg KH <> | Subject | Re: [RFC PATCH v2 1/2] kernfs: use kernfs_node specific mutex and spinlock. |
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On Mon, Jan 03, 2022 at 07:45:43PM +1100, Imran Khan wrote: > diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h > index 861c4f0f8a29..5ed4c9ed39af 100644 > --- a/include/linux/kernfs.h > +++ b/include/linux/kernfs.h > @@ -164,6 +164,8 @@ struct kernfs_node { > unsigned short flags; > umode_t mode; > struct kernfs_iattrs *iattr; > + spinlock_t kernfs_open_node_lock; > + struct mutex kernfs_open_file_mutex;
Did you just blow up the memory requirements of a system with lots of kobjects created?
We used to be able to support tens of thousands of scsi devices in a 32bit kernel, with this change, what is the memory difference that just happened?
There is a tradeoff of memory usage and runtime contention that has to be made here, and this might be pushing it in the wrong direction for a lot of systems.
thanks,
greg k-h
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