From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 244A57404E for ; Fri, 4 Apr 2025 21:26:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743802002; cv=none; b=Ri3ae4jbpFgwELWioWinXWY8IQqQ6RpvvQfW2KFp2qv2mdAhcWTWKkEhhjYEPyWJTRUeguloQmxT7cTlNW9iertvNnuiBfmyP4A/kjrqB9z79D8e552nSrhK3WmTETLI+YQgUIiu3vOyi1hDgL8NHZL1dLopVf+I7CoCcdw3YLI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743802002; c=relaxed/simple; bh=Z3+mmQiW3eqWuD9CkXjlwt8VlJTraYnnMsQPCuzP69E=; h=From:To:Subject:Date:Message-ID:In-Reply-To:References: Content-Type:MIME-Version; b=hsEX3jgICNDRax7CbiuLyn5+/oC9YwyXFFrqn9in3TnKbDlPav6LLhJgN34BRgemaLzjRNnezfp0GINEeCDfN2UY9yzG/PbxZShM9zcG9KRlwPebKA3klx0AjgDObTjrYnjlq5Bk5jLe7IkxTVwzZ302JBbzCuckrdTKZ5+JJ+8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=VGHJp8c4; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="VGHJp8c4" Received: by smtp.kernel.org (Postfix) with ESMTPS id 8BDF8C4CEE4 for ; Fri, 4 Apr 2025 21:26:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1743802001; bh=Z3+mmQiW3eqWuD9CkXjlwt8VlJTraYnnMsQPCuzP69E=; h=From:To:Subject:Date:In-Reply-To:References:From; b=VGHJp8c4DVSzM/KCLeY81wEf1gTfgdKae1P78LWqOEsWUrKEhUC1u78uIywVQb/UW x5kIgTreW+GEXCURgdm2bUR3KFRq2zXJkgASAVy0HxH5LhCtCt69nTZvN4QoUy4nza cL7/sR9CehsJOjJ9VbVXy9sFDT4vYQcPmmX2P5hnHpEtmwMEJjjvcReG/+jCDw/mOq s/ruGvta9O51qtym/YV2Qcl8D5X7w3zaCAIILr/4kPY3GmI4eQo3RYefQZ22N33AMu VNULLTEPCwsbVexW8vDn9r36Lug9UDblIs/oVwcbhGQcM+h7gmX5127gQoR/EZG6Ve mQe3/Vvq6WHNg== Received: by aws-us-west-2-korg-bugzilla-1.web.codeaurora.org (Postfix, from userid 48) id 80AD6C41612; Fri, 4 Apr 2025 21:26:41 +0000 (UTC) From: bugzilla-daemon@kernel.org To: kvm@vger.kernel.org Subject: [Bug 217379] Latency issues in irq_bypass_register_consumer Date: Fri, 04 Apr 2025 21:26:41 +0000 X-Bugzilla-Reason: None X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: AssignedTo virtualization_kvm@kernel-bugs.osdl.org X-Bugzilla-Product: Virtualization X-Bugzilla-Component: kvm X-Bugzilla-Version: unspecified X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: seanjc@google.com X-Bugzilla-Status: NEW X-Bugzilla-Resolution: X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: virtualization_kvm@kernel-bugs.osdl.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: cc Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugzilla.kernel.org/ Auto-Submitted: auto-generated Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 https://bugzilla.kernel.org/show_bug.cgi?id=3D217379 Sean Christopherson (seanjc@google.com) changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |seanjc@google.com --- Comment #3 from Sean Christopherson (seanjc@google.com) --- Huh. Rereading this almost two years later, I realized I completely missed that (a) your setup wasn't actually using irqbypass and (b) you suggested giving userspace a way to disable irqbypass in KVM when it couldn't possibl= y be utilized. I've proposed adding a module param for other reasons[1]. If that doesn't suffice, KVM could also provide KVM_IRQFD_FLAG_NO_IRQBYPASS (which would al= so be useful for other reasons). As for the ugly latency problems, I posted a new patch to use xarray to mitigate the issue[2]. [1] https://lore.kernel.org/all/20250401161804.842968-1-seanjc@google.com [2] https://lore.kernel.org/all/20250404211449.1443336-1-seanjc@google.com --=20 You may reply to this email to add a comment. You are receiving this mail because: You are watching the assignee of the bug.=