]> www.infradead.org Git - users/jedix/linux-maple.git/commit
x86/mm/tlb: Also remove local CPU from mm_cpumask if stale
authorRik van Riel <riel@surriel.com>
Thu, 5 Dec 2024 15:46:30 +0000 (10:46 -0500)
committerIngo Molnar <mingo@kernel.org>
Fri, 6 Dec 2024 09:25:53 +0000 (10:25 +0100)
commit953753db887f9d70f70f61d6ecbe5cf209107672
treecf7767890d97be7a22263826306ed2d2434bf6d3
parent2815a56e4b7252a836969f5674ee356ea1ce482c
x86/mm/tlb: Also remove local CPU from mm_cpumask if stale

The code in flush_tlb_func() that removes a remote CPU from the
cpumask if it is no longer running the target mm is also needed
on the originating CPU of a TLB flush, now that CPUs are no
longer cleared from the mm_cpumask at context switch time.

Flushing the TLB when we are not running the target mm is
harmless, because the CPU's tlb_gen only gets updated to
match the mm_tlb_gen, but it does hit this warning:

        WARN_ON_ONCE(local_tlb_gen > mm_tlb_gen);

  [ 210.343902][ T4668] WARNING: CPU: 38 PID: 4668 at arch/x86/mm/tlb.c:815 flush_tlb_func (arch/x86/mm/tlb.c:815)

Removing both local and remote CPUs from the mm_cpumask
when doing a flush for a not currently loaded mm avoids
that warning.

Reported-by: kernel test robot <oliver.sang@intel.com>
Tested-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Rik van Riel <riel@surriel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20241205104630.755706ca@fangorn
Closes: https://lore.kernel.org/oe-lkp/202412051551.690e9656-lkp@intel.com
arch/x86/mm/tlb.c