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In order to shrink drm_display_mode below the magic two cacheline mark in 64bit we need to shrink it by another 8 bytes. The easiest thing to eliminate is the 'export_head' list head which is only used during the getconnector ioctl to temporarly track which modes on the connector's mode list are to be exposed and which are to remain hidden. We can simply replace the list head with a boolean which we use to tag the modes that are to be exposed. If we make sure to clear the tags after we're done with them we don't even need an extra loop over the modes to reset the tags at the start of the getconnector ioctl. Conveniently we already have a hole for the boolean left behind by the removal of mode->private_flags. The final size of the struct is now 112 bytes on 32bit and 120 bytes on 64bit. Another alternative would be a temp bitmask so we wouldn't have to have anything in the mode struct itself. The main issue is how large of a bitmask do we need? I guess we could allocate it dynamically but that means an extra kcalloc() and an extra loop through the modes to count them first (or grow the bitmask with krealloc() as needed). CC: Sam Ravnborg <sam@ravnborg.org> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Emil Velikov <emil.l.velikov@gmail.com> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200428171940.19552-17-ville.syrjala@linux.intel.com Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.