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[159.2.239.150]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-90c5eec2f0csm73294756d6.14.2026.08.21.14.55.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 21 Aug 2026 14:55:59 -0700 (PDT) Received: from jgg by wakko with local (Exim 4.97) (envelope-from ) id 1wxXDS-000000074tz-27sh; Fri, 21 Aug 2026 18:55:58 -0300 Date: Fri, 21 Aug 2026 18:55:58 -0300 From: Jason Gunthorpe To: "Liam R. Howlett (Oracle)" Cc: Rik van Riel , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, maple-tree@lists.infradead.org Subject: Re: [PATCH v3 15/19] maple_tree: Document erase and allocations better Message-ID: <20260821215558.GA1449020@ziepe.ca> References: <20260821192627.4085470-1-liam@infradead.org> <20260821192627.4085470-16-liam@infradead.org> <500549bf86f8fab571424af9a7f3a69bb1a08a5b.camel@surriel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Rspamd-Queue-Id: 9B0FD100005 X-Rspamd-Server: rspam10 X-Rspam-User: X-Stat-Signature: cidp7pt5kpx4ob6ftks4ce4p34gepptb X-HE-Tag: 1787349361-624462 X-HE-Meta: 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 n0s5mRX1 5QfZgbkWf9+OtnmPy59Mzorl+IL/cJA8y9tCUcDEIxFfARQoglE0Q+fpN7fs5CjwfYnCDHZm6jn8AOq71GiQ5aEvcwQzEm3kTTE263awS0AkNFLM1E95hnTRPPa9WCZbC76ZjDkJ/ReioNVr8+mhN3JGKE748qXnEpw9RjHPj5JusPAHlWrxd6MIH779QGNbiJ3NH4GknFep6oKNX1NPgPFwq6wmsSqyv6VNQ+bBBAdBZiCuvCQOkRIkkQJxviz3npTQwsKR/jiuvpJQ0GiHD+B4oCsa2x8mPjBrLKcEyCTzp7XlJV8ih7I2XHIfRrM39sUBPGrHh26l86TmDdSZ4LhZqqwnSTDIuuAmv Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Fri, Aug 21, 2026 at 04:37:48PM -0400, Liam R. Howlett (Oracle) wrote: > On 26/08/21 03:34PM, Rik van Riel wrote: > > On Fri, 2026-08-21 at 15:26 -0400, Liam R. Howlett (Oracle) wrote: > > > > > >  knowing one value within that range, or mtree_store() call with an > > > entry of > > > -NULL may be used to partially erase a range or many ranges at once. > > > +NULL may be used to partially erase a range or many ranges at once.  > > > Note that > > > +mtree_erase() may use GFP_KERNEL | __GFP_NOFAIL for allocations and > > > cannot > > > +fail, but may need to sleep - do not use mtree_erase() from a > > > blocking context. > > > > > > > Do you mean "from a context that cannot block" ? > > Ah, that's not clear. > > "Do not use mtree_erase() from a context that cannot tolerate blocking" > > Is that better? I would say 'can sleep, so must not be called from an atomic context' ? If that is what you mean.. Jason