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b=J4NOZ3+F/wcCmEWLMyxtMF9GufxOdiPWEJI8FjD81Zi0epu/A0mcp8gt23izr6n4f 86B1xrYhjtkwryopz9jIVKj4zX0kBJ0++ccJSdXCtujeMEIYOh3dvGUfB2ntWo3AAb kF/D7CDVvSaaGZpJuCFOkJEDRVWoHv39Vumf2zgRucUeJZVAADKyFzNS7hP23fCrCB HMHVLNFXfG3g0z0Z+9Ozuw6YB354HaP/w5eoPMvA3vJFuURb7VS+JlBokheQDS5HKG 1hxJusWy8nEyoTDgDLLFEHYSTikww4QzLbCjZ90tylGShH+rC5VsGgNYutNKeRwAPC 5k7ucS2PrYDHQ== From: Pratyush Yadav To: Pasha Tatashin Cc: akpm@linux-foundation.org, brauner@kernel.org, corbet@lwn.net, graf@amazon.com, jgg@ziepe.ca, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org, masahiroy@kernel.org, ojeda@kernel.org, pratyush@kernel.org, rdunlap@infradead.org, rppt@kernel.org, tj@kernel.org, yanjun.zhu@linux.dev Subject: Re: [PATCH v9 6/9] kho: don't unpreserve memory during abort In-Reply-To: <20251101142325.1326536-7-pasha.tatashin@soleen.com> (Pasha Tatashin's message of "Sat, 1 Nov 2025 10:23:22 -0400") References: <20251101142325.1326536-1-pasha.tatashin@soleen.com> <20251101142325.1326536-7-pasha.tatashin@soleen.com> Date: Wed, 05 Nov 2025 11:28:01 +0100 Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) MIME-Version: 1.0 Content-Type: text/plain X-Stat-Signature: aaqoejuajcoao7sxm3pkzder153wu5o7 X-Rspam-User: X-Rspamd-Queue-Id: 8065A1C0002 X-Rspamd-Server: rspam01 X-HE-Tag: 1762338486-638075 X-HE-Meta: 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 uJqyztQL nu/dNbLDnXBd/WR8omOEV4rmyRUX4x6nUiepWyf2F4lW/JSB2Jf6BhEz75SxYI0iNoJj0by6MVU9z8nz9KPuAGKg/7eMLdeIUkbn69Ej8Ufj72R8Ljag6smgMNirtN0T1oeL4Lu399ivfd7Um/ZVrsY1TCfQTP8/l0BdoWiu0jLUNTYOgvFDOJ0DIXDHypisWRyBK2h52rNV0KliZ/z6MpFE7qVnaqYJJF7wvwh9nwkFmXJ0U4KBKbI0oVxxCc7w49Nxt X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Sat, Nov 01 2025, Pasha Tatashin wrote: > KHO allows clients to preserve memory regions at any point before the > KHO state is finalized. The finalization process itself involves KHO > performing its own actions, such as serializing the overall > preserved memory map. > > If this finalization process is aborted, the current implementation > destroys KHO's internal memory tracking structures > (`kho_out.ser.track.orders`). This behavior effectively unpreserves > all memory from KHO's perspective, regardless of whether those > preservations were made by clients before the finalization attempt > or by KHO itself during finalization. > > This premature unpreservation is incorrect. An abort of the > finalization process should only undo actions taken by KHO as part of > that specific finalization attempt. Individual memory regions > preserved by clients prior to finalization should remain preserved, > as their lifecycle is managed by the clients themselves. These > clients might still need to call kho_unpreserve_folio() or > kho_unpreserve_phys() based on their own logic, even after a KHO > finalization attempt is aborted. > > Signed-off-by: Pasha Tatashin Reviewed-by: Pratyush Yadav [...] -- Regards, Pratyush Yadav