Date:   Mon, 20 Mar 2023 09:49:02 +0100
From:   Peter Zijlstra <peterz@infradead.org>
To:     Yair Podemsky <ypodemsk@redhat.com>
Cc:     will@kernel.org, aneesh.kumar@linux.ibm.com,
        akpm@linux-foundation.org, npiggin@gmail.com, arnd@arndb.de,
        linux-arch@vger.kernel.org, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org, mtosatti@redhat.com,
        ppandit@redhat.com, alougovs@redhat.com,
        David Hildenbrand <david@redhat.com>
Subject: Re: [PATCH] mm/mmu_gather: send tlb_remove_table_smp_sync IPI only
 to MM CPUs
Message-ID: <20230320084902.GE2194297@hirez.programming.kicks-ass.net>
References: <20230312080945.14171-1-ypodemsk@redhat.com>
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On Sun, Mar 12, 2023 at 10:09:45AM +0200, Yair Podemsky wrote:
> Currently the tlb_remove_table_smp_sync IPI is sent to all CPUs
> indiscriminately, this causes unnecessary work and delays notable in
> real-time use-cases and isolated cpus, this patch will limit this IPI to
> only be sent to cpus referencing the effected mm and are currently in
> kernel space.

Did you validate that all architectures for which this is relevant
actually set bits in mm_cpumask() ?