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charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspam-User: X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: D5A09120007 X-Stat-Signature: 6k1md9ma9adsk33cj73j74bryrh457qf X-HE-Tag: 1775765450-335818 X-HE-Meta: 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 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 4/9/26 08:57, Zi Yan wrote: > Historically, THP support on x86 checked the PSE feature bit to enable > THP. On 64-bit, this check is redundant since PSE is always enabled by > default for compatibility. What do you mean by "PSE is always enabled by default"? A hypervisor is completely free to not enumerate PSE support to a guest. Any kernel can disable PSE with clearcpuid=3 on the command-line. PSE is also disabled for at least one erratum (which I think includes some 64-bit CPUs). Here's a snippet in a 64-bit VM of /proc/cpuinfo on a normal boot: DirectMap4k: 83836 kB DirectMap2M: 1939456 kB DirectMap1G: 1048576 kB and with clearcpuid=3: DirectMap4k: 3071868 kB DirectMap2M: 0 kB Just to show that it's possible. So perhaps I'm reading into the changelog too much, but this doesn't quite seem right to me.