From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from layka.disroot.org (layka.disroot.org [178.21.23.139]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 716543DA7CA for ; Mon, 18 May 2026 05:51:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=178.21.23.139 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779083465; cv=none; b=ARb00vtlC4KYk9bhYGENi3mX/ecfqRs6Fff7q2MX55Bam54/lkYqJLThnsJA3/ccRUvG9uURGXqQxOTEx7RM2voQ0u04tuxdixBHLUhukOi/uTyb8L9dkGTLZW+Sn6In/fGHm+HppqYuNeXWqN/RKnwdbh0tOs/apM+zpMNC3dE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779083465; c=relaxed/simple; bh=8ezwosqfreL+dwXd+rndGKo9xks52ZgMJWdDr8Dzw8k=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type: Content-Disposition; b=mfIaRkvl6Q1gUp4ZSM9lgWmjMzeKjck+G1rRFB4/ApwrZCaQnnC0W8khp/bPJGkyb83huWzB8A3sUdD0ZG+7fsrWmEVDRadbmLfKpCt636nnqhE8LjK/43IsrKqHfs8yWasEdWODcxq7d6dsHL2XHTd+NUa5CSApmqzBASKbgOs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=proton.me; spf=pass smtp.mailfrom=disroot.org; arc=none smtp.client-ip=178.21.23.139 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=proton.me Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=disroot.org Received: from mail01.disroot.lan (localhost [127.0.0.1]) by disroot.org (Postfix) with ESMTP id 4B8D42756F; Mon, 18 May 2026 07:50:56 +0200 (CEST) X-Virus-Scanned: SPAM Filter at disroot.org Received: from layka.disroot.org ([127.0.0.1]) by localhost (disroot.org [127.0.0.1]) (amavis, port 10024) with ESMTP id wdnxBDz-5nro; Mon, 18 May 2026 07:50:55 +0200 (CEST) Date: Mon, 18 May 2026 06:50:47 +0100 From: funsafemath To: Alejandro Colomar Cc: linux-man@vger.kernel.org Subject: [PATCH] man/man2/seccomp_unotify.2: Document SECCOMP_IOCTL_NOTIF_SET_FLAGS and SECCOMP_USER_NOTIF_FD_SYNC_WAKE_UP Message-ID: X-Developer-Signature: v=1; a=openpgp-sha256; l=2319; i=funsafemath@proton.me; h=from:subject; bh=j8lHGvALPQVAHTN6LQdcZG7ASTMpjs9S72ca6JInTsQ=; b=owGbwMvMwCV2QvA6L+scLT/G02pJDFlcy3vlqiZf4Nat++d8zz3J4qNg/4Hk7hnfeg85xB86F cq34LV3RykLgxgXg6yYIovEwju+Urrqn+0/p6rCzGFlAhnCwMUpABOpXcDIcL1l7paY5FuPAht6 DDT7ekU80+9HbZ+/9pxHwNETDJWXNjL8Zp2zPlzfjH3SKp6HEldFA3LinHz/c/gY5D1K1V37siC GBwA= X-Developer-Key: i=funsafemath@proton.me; a=openpgp; fpr=B07EE98D22F23DFB077429C0DF66F4774CE714D5 Precedence: bulk X-Mailing-List: linux-man@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="h6h7v5srgvqqfxbp" Content-Disposition: inline --h6h7v5srgvqqfxbp Content-Type: text/plain; protected-headers=v1; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Subject: [PATCH] man/man2/seccomp_unotify.2: Document SECCOMP_IOCTL_NOTIF_SET_FLAGS and SECCOMP_USER_NOTIF_FD_SYNC_WAKE_UP MIME-Version: 1.0 Document the SECCOMP_IOCTL_NOTIF_SET_FLAGS ioctl(2) operation and its only = flag, SECCOMP_USER_NOTIF_FD_SYNC_WAKE_UP, which advises the scheduler to move the supervisor to the CPU on which the target process is executing for faster context switches. Signed-off-by: funsafemath --- man/man2/seccomp_unotify.2 | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) diff --git a/man/man2/seccomp_unotify.2 b/man/man2/seccomp_unotify.2 index a5c1a4423..70b2996a9 100644 --- a/man/man2/seccomp_unotify.2 +++ b/man/man2/seccomp_unotify.2 @@ -27,6 +27,7 @@ .SH SYNOPSIS .BI "int ioctl(int " fd ", SECCOMP_IOCTL_NOTIF_ID_VALID, __u64 *" id ); .BI "int ioctl(int " fd ", SECCOMP_IOCTL_NOTIF_ADDFD," .BI " struct seccomp_notif_addfd *" addfd ); +.BI "int ioctl(int " fd ", SECCOMP_IOCTL_NOTIF_SET_FLAGS, unsigned long " = flags ); .fi .SH DESCRIPTION This page describes the user-space notification mechanism provided by the @@ -881,6 +882,41 @@ .SS SECCOMP_IOCTL_NOTIF_ADDFD ioctl(notifyFd, SECCOMP_IOCTL_NOTIF_SEND, resp); .in .EE +.\" +.SS SECCOMP_IOCTL_NOTIF_SET_FLAGS +The +.B SECCOMP_IOCTL_NOTIF_SET_FLAGS +operation (available since Linux 6.6) +\." commit 48a1084a8b7423642b5f17ca6202f6f277c5392b +is used to modify the behavior of the seccomp user-space notification mech= anism. +.P +The third +.BR ioctl (2) +argument, +.IR flags , +is a bit mask that includes zero or more of the following flags: +.RS +.TP +.BR SECCOMP_USER_NOTIF_FD_SYNC_WAKE_UP " (since Linux 6.6)" +\." commit 48a1084a8b7423642b5f17ca6202f6f277c5392b +Advise the scheduler to move the supervisor to the current CPU. +.IP +In workflows where the target and supervisor wait for each other +(do not execute in parallel), +this flag makes the context switches a few times faster. +.RE +.P +On success, +this operation returns 0; +on failure, \-1 is returned, and +.I errno +is set to indicate the error. +This operation can fail with the following errors: +.TP +.B EINVAL +An invalid value was specified in the +.I flags +argument. .SH NOTES One example use case for the user-space notification mechanism is to allow a container manager --=20 2.52.0 --h6h7v5srgvqqfxbp Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQQYodxNGi0n8z/zZSXIEdcNBZwqTgUCagqotAAKCRDIEdcNBZwq TpsCAQCFfmtEJpzXjFNiIUMDw6UVOsbERejdiIGyHI0ruUc5bQD/V0JXrycz5BFU wbU7CRqDdNICtC9totHO1O6MGT4+UQ4= =ih4v -----END PGP SIGNATURE----- --h6h7v5srgvqqfxbp--