Re: [RFC PATCH 1/3] Revert "binder_alloc: add missing mmap_lock calls when using the VMA"

From: Greg Kroah-Hartman
Date: Tue Apr 25 2023 - 01:19:28 EST


On Mon, Apr 24, 2023 at 08:55:46PM +0000, Carlos Llamas wrote:
> This reverts commit 44e602b4e52f70f04620bbbf4fe46ecb40170bde.
>
> This caused a performance regression particularly when pages are getting
> reclaimed. We don't need to acquire the mmap_lock to determine when the
> binder buffer has been fully initialized. A subsequent patch will bring
> back the lockless approach for this.
>
> [cmllamas: resolved trivial conflicts with renaming of alloc->mm]
>
> Cc: Liam Howlett <liam.howlett@xxxxxxxxxx>
> Cc: Suren Baghdasaryan <surenb@xxxxxxxxxx>
> Signed-off-by: Carlos Llamas <cmllamas@xxxxxxxxxx>
> ---
> drivers/android/binder_alloc.c | 31 ++++++++++---------------------
> 1 file changed, 10 insertions(+), 21 deletions(-)

Why is this series "RFC"? What needs to be done to be able to submit it
as a real patch series?

Also, as the commits you are reverting are in older kernels, please
properly cc: stable in the signed-off-by area, and add a fixes: tag for
the commit you are reverting when you resend these as a real series.

thanks,

greg k-h