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b=NxyNB81U8f6PAWeUwwzdOtXaPmfXw7FN3QcqQjIIsCcH5VI5wVZu0Ri+B0XMGGqpJ sOXEJzTx0wNrc+VdxL3vKDs1JhUbhxK4wJuuvfYYtqSK8osdipx93Lqyd50Pky+nvC UZrtQ+Niv5k6gGiLF7ncwKcd+kzEUPC1tec3Mz7daR+93cf1lp3WVCpsi31K6y0lIq SSOVvte+SXrOBSFM5dpv9604d1hwa2RLdt6tBQCVXUG900N+sQVVK9vlB+W7DPcK65 vUgSD7hSlWBD8L3frOT8VdZ7lOAwwFziaota7Gqui/gjq0EwTIpm5sqrKNeOzSN3Vq la0AaQFHvyjJQ== Date: Wed, 16 Sep 2026 14:03:29 +0100 From: "Lorenzo Stoakes (ARM)" To: Gregory Price Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-team@meta.com, akpm@linux-foundation.org, liam@infradead.org, david@kernel.org, vbabka@kernel.org, jannh@google.com, wangjiexun@tinylab.org, sashiko-bot , stable@vger.kernel.org Subject: Re: [PATCH] mm/madvise: reclaim isolated folios if PTE restart fails Message-ID: References: <20260912110832.3203902-1-gourry@gourry.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspam-User: X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: EB5C91C0010 X-Stat-Signature: frpoy3teuj7mmprjgbycshbq9pubpipi X-HE-Tag: 1789563815-847988 X-HE-Meta: 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 gkxb9ozE tW0mkZHxdoXgqtGeVF59/CzaCQRGLKfXzJRoO54cpxBb6r2KXjHwnRJU18eh8NTxY11lfi4qKiuuiAhmHrmHmJzkIJWtBaARaMBLVzf0zeo0QHwklJvsjOaVnIOn6H6bvBs+eLSFo2NWz7ShRkie3PwyI8CuTdAKyW4LWlePmBZM0h1kVMPjLATBFjkp+6R0oGJsEo9TGLpCJ8Qq4p1Xv+NSFSCKZzDKra4IkrTj/rO1hs23znnIu4ja3viNvrnXTbXf5 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Tue, Sep 15, 2026 at 01:12:03PM -0400, Gregory Price wrote: > On Tue, Sep 15, 2026 at 04:55:47PM +0100, Lorenzo Stoakes (ARM) wrote: > > On Sat, Sep 12, 2026 at 07:08:32AM -0400, Gregory Price wrote: > > > MADV_PAGEOUT collects isolated folios on a local list before reclaiming > > > them after the PTE walk. The reschedule path drops the PTE lock and then > > > restarts the mapping with pte_offset_map_lock(). > > > > Is this reschedule path even necessary? It's pretty bloody sketchy. > > > > I thought the modern approach (TM) was to not do cond_resched() and friends so > > can we actually look at removing this? > > > > Sorry - meant to reply to this. > > Honestly there's so much jammed into this function i can't give you a > straight answer. I can take a short detour to figure out if we can > rework this as a whole. s/short detour/long journey through hell/ perhaps? :P ;) > > ~Gregory -- Cheers, Lorenzo