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[109.81.23.83]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-48150bf5f0esm4963432f8f.4.2026.08.12.01.14.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 12 Aug 2026 01:14:33 -0700 (PDT) Date: Wed, 12 Aug 2026 10:14:32 +0200 From: Michal Hocko To: David Woodhouse Cc: Steven Rostedt , Jason Gunthorpe , Andrew Morton , David Hildenbrand , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Sebastian Andrzej Siewior , Clark Williams , Simona Vetter , =?iso-8859-1?B?Suly9G1l?= Glisse , Christian =?iso-8859-1?Q?K=F6nig?= , "Paul E. McKenney" , Sean Christopherson , Paolo Bonzini , linux-mm@kvack.org, kvm@vger.kernel.org, linux-rt-devel@lists.linux.dev, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm/mmu_notifier: Remove non_block_start/end() from notifier invocation Message-ID: References: <20260811135537.GC544626@ziepe.ca> <1d669aca4ffee797b9c29215382444a5b23624b3.camel@infradead.org> <20260811142730.GG544626@ziepe.ca> <20260811104229.72fdd928@gandalf.local.home> <37b83b429b9f14ea6ad4ca1c13cc8e565ec09033.camel@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <37b83b429b9f14ea6ad4ca1c13cc8e565ec09033.camel@infradead.org> X-Stat-Signature: fy137mogzj6mxwpy31pdb5fkgai3c8bs X-Rspamd-Queue-Id: A2B4A20002 X-Rspamd-Server: rspam03 X-Rspam-User: X-HE-Tag: 1786522475-905803 X-HE-Meta: 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 HaQpAGt0 ek3T9IBdq8Ha22PR+Ae+5vsfy9ZGnwpqrb67bmzBpeP4st7/mHzbBvp0LtSXI+KMD8tR55BzP31acM2od4HxZl2O5PKF9M5PXLtK0I08VK3bmMO4a22/2VPvi2CH3KHETRw50dndf49Sztzmj7GcTBFahaIXH8RFWGe0eFbR3Zs9R2IAhIB+3MjRdo8MBYA9wYC9B5TOuhhG5HNMExthOzA0fOyXrgZZP93fxEOyRi0wPBOONUPfnlCvsjv+aXCBAf8hIbekIVnsq4cKErof/wTKeN0Q/46H7TRz7ofuW3uCozlAyZmRInuLbUoTd9Pw08W/BtBPtimHexGgB3Cd+XvkzRXY9sPSMRiuAZG95xecaJO9+78Zzw4095ABq3wg1hXLzT4HoIUPtXUQf+PNP+q2xpQ== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Tue 11-08-26 16:24:48, David Woodhouse wrote: [...] > I had a second reason for disabling the overzealous check too: to allow > SRCU grace periods within the notifier callbacks. Is there a way that srcu barrier could cause an indirect dependency on memory allocation? In other words what might block the scru to complete? -- Michal Hocko SUSE Labs