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b=o0Lw7dm+WDNqh8UKtgSTrRp1KEGb1+HzQ25D4x3Qlj1zY0y+wipo4fB8Ut2CDs2Kt EO504uFug0dUTpMEOA1YXEr1kOvaK7TM+zIB6iX9Pesk0ENVyuV/l/QR6C7yl28g0F DzZWd4AH4VUK9GRcDdbvRb83Yk25ik7CisUQLJDDV6pT/Uir6R7B7a/RmEqsT0KjDr T+BMOqi0YSOW5RLQ6B25Gbm/IYwjC0uhlhNW+1nAhV1W02NEjCDc0+GFOPRkKyXs7d ROxvsJAhIAUu99ziG6QNm1/eYdnihmAeW60wrWqK+Gd0DQzapA/1ZH4yF+Wh0g3fCF 6exIA62+ATVwQ== Date: Mon, 15 Sep 2025 19:11:12 +0300 From: Mike Rapoport To: Jason Gunthorpe Cc: Andrew Morton , Alexander Graf , Baoquan He , Changyuan Lyu , Chris Li , Pasha Tatashin , Pratyush Yadav , kexec@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 1/2] kho: add support for preserving vmalloc allocations Message-ID: References: <20250908103528.2179934-1-rppt@kernel.org> <20250908103528.2179934-2-rppt@kernel.org> <20250908141423.GJ616306@nvidia.com> <20250915143730.GK1024672@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250915143730.GK1024672@nvidia.com> X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: F0F21A0007 X-Stat-Signature: rgqewmxtuxhra1ooxjja6cz4bpdmri5g X-Rspam-User: X-HE-Tag: 1757952681-913222 X-HE-Meta: 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 ejyrXgEK yem+5xckOMHM+aelZkVQDwUsF/n6b1kL37pBHS249lDaiwPeqpC5ODLejWmbAUxytYiSVNmVxbPOBoK7UjvJ+FeNvKbf2tbI53VfYlyFwgs0KP7Zj4zRbgrvs/5U7cXq2Kb6knyV4Ukoby+EBxeNv0HuhCcOtUrQAOm8Pf87QKV1tum0IAgmIdhudZUdosoC86SGEcJxjineJFROX+3p6oHjp3G1+LORU9Ez5GSrDKHMBcAXMhtmOvorRXQjj8cuJWjIy 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 Mon, Sep 15, 2025 at 11:37:30AM -0300, Jason Gunthorpe wrote: > On Mon, Sep 15, 2025 at 05:01:01PM +0300, Mike Rapoport wrote: > > > kzalloc() cannot be preserved, the only thing we support today is > > > alloc_page(), so this code pattern shouldn't exist. > > > > kzalloc(PAGE_SIZE) can be preserved, it's page aligned and we don't have to > > restore it into a slab cache. But this maybe indeed confusing for those who > > copy paste the code, so I'll change it. > > It really isn't. The kzalloc should be returning frozen pages for that > allocation and the restoration will not put frozen pages back. But we don't care here, we free that page immediately to buddy on restoration. > Jason -- Sincerely yours, Mike.