From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [103.22.144.67]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id D86ED1A028E for ; Mon, 8 Feb 2016 17:01:19 +1100 (AEDT) Date: Mon, 8 Feb 2016 16:59:54 +1100 From: Paul Mackerras To: David Gibson Cc: mpe@ellerman.id.au, benh@kernel.crashing.org, linuxppc-dev@lists.ozlabs.org, aik@ozlabs.ru, thuth@redhat.com, lvivier@redhat.com Subject: Re: [RFCv2 7/9] pseries: Add support for hash table resizing Message-ID: <20160208055954.GG30807@oak.ozlabs.ibm.com> References: <1454045043-25545-1-git-send-email-david@gibson.dropbear.id.au> <1454045043-25545-8-git-send-email-david@gibson.dropbear.id.au> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1454045043-25545-8-git-send-email-david@gibson.dropbear.id.au> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Fri, Jan 29, 2016 at 04:24:01PM +1100, David Gibson wrote: > This adds support for using experimental hypercalls to change the size > of the main hash page table while running as a PAPR guest. For now these > hypercalls are only in experimental qemu versions. > > The interface is two part: first H_RESIZE_HPT_PREPARE is used to allocate > and prepare the new hash table. This may be slow, but can be done > asynchronously. Then, H_RESIZE_HPT_COMMIT is used to switch to the new > hash table. This requires that no CPUs be concurrently updating the HPT, > and so must be run under stop_machine(). > > This also adds a debugfs file which can be used to manually control > HPT resizing or testing purposes. > > Signed-off-by: David Gibson Reviewed-by: Paul Mackerras