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[209.85.218.43]) by smtp.gmail.com with ESMTPSA id be10-20020a1709070a4a00b00a461d2a3374sm1815779ejc.47.2024.03.11.13.05.23 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 11 Mar 2024 13:05:23 -0700 (PDT) Received: by mail-ej1-f43.google.com with SMTP id a640c23a62f3a-a44cdb2d3a6so672214666b.2 for ; Mon, 11 Mar 2024 13:05:23 -0700 (PDT) X-Forwarded-Encrypted: i=1; AJvYcCV/OfUKCXl/JcybHZkoUmVP4tMec/GugrBZS7EOchnB9t2Ewn9Ep8E1LLET36731BYGWEWZ5BG+E+UL/vYHcFdpEkL+GRObO0081YRj X-Received: by 2002:a17:906:c34e:b0:a45:ab1a:4c31 with SMTP id ci14-20020a170906c34e00b00a45ab1a4c31mr991274ejb.56.1710187522843; Mon, 11 Mar 2024 13:05:22 -0700 (PDT) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <20240308-vfs-pidfd-b106369f5406@brauner> In-Reply-To: <20240308-vfs-pidfd-b106369f5406@brauner> From: Linus Torvalds Date: Mon, 11 Mar 2024 13:05:06 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [GIT PULL] vfs pidfd To: Christian Brauner Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" On Fri, 8 Mar 2024 at 02:14, Christian Brauner wrote: > > * Move pidfds from the anonymous inode infrastructure to a tiny > pseudo filesystem. This will unblock further work that we weren't able > to do simply because of the very justified limitations of anonymous > inodes. Moving pidfds to a tiny pseudo filesystem allows for statx on > pidfds to become useful for the first time. They can now be compared > by inode number which are unique for the system lifetime. So I obviously pulled this already, but I did have one question - we don't make nsfs conditional, and I'm not convinced we should make pidfs conditional either. I think (and *hope*) all the semantic annoyances got sorted out, and I don't think there are any realistic size advantages to not enabling CONFIG_FS_PID. Is there some fundamental reason for that config entry to exist? Linus