From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43032) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ebVHi-0002rB-8B for qemu-devel@nongnu.org; Tue, 16 Jan 2018 12:44:31 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ebVHd-0006Vp-H2 for qemu-devel@nongnu.org; Tue, 16 Jan 2018 12:44:30 -0500 Received: from mx1.redhat.com ([209.132.183.28]:42896) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ebVHd-0006VR-Ao for qemu-devel@nongnu.org; Tue, 16 Jan 2018 12:44:25 -0500 Date: Tue, 16 Jan 2018 17:43:42 +0000 From: "Dr. David Alan Gilbert" Message-ID: <20180116174341.GD2521@work-vm> References: <20180115115309.23982-1-quintela@redhat.com> <20180115115309.23982-10-quintela@redhat.com> <215cfa8f-1f2d-1155-bd0b-17ecd10c4c61@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <215cfa8f-1f2d-1155-bd0b-17ecd10c4c61@redhat.com> Subject: Re: [Qemu-devel] [PULL 09/27] migration: calculate vCPU blocktime on dst side List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Max Reitz Cc: Juan Quintela , qemu-devel@nongnu.org, lvivier@redhat.com, peterx@redhat.com, Alexey Perevalov * Max Reitz (mreitz@redhat.com) wrote: > On 2018-01-15 12:52, Juan Quintela wrote: > > From: Alexey Perevalov > > > > This patch provides blocktime calculation per vCPU, > > as a summary and as a overlapped value for all vCPUs. > > > > This approach was suggested by Peter Xu, as an improvements of > > previous approch where QEMU kept tree with faulted page address and cpus bitmask > > in it. Now QEMU is keeping array with faulted page address as value and vCPU > > as index. It helps to find proper vCPU at UFFD_COPY time. Also it keeps > > list for blocktime per vCPU (could be traced with page_fault_addr) > > > > Blocktime will not calculated if postcopy_blocktime field of > > MigrationIncomingState wasn't initialized. > > > > Signed-off-by: Alexey Perevalov > > Reviewed-by: Dr. David Alan Gilbert > > Reviewed-by: Juan Quintela > > Signed-off-by: Juan Quintela > > --- > > migration/postcopy-ram.c | 143 ++++++++++++++++++++++++++++++++++++++++++++++- > > migration/trace-events | 5 +- > > 2 files changed, 146 insertions(+), 2 deletions(-) > > For me, this breaks compilation with clang -m32: > > LINK x86_64-softmmu/qemu-system-x86_64 > ../migration/postcopy-ram.o: In function `mark_postcopy_blocktime_begin': > /home/maxx/projects/qemu/migration/postcopy-ram.c:599: undefined > reference to `__atomic_exchange_8' > /home/maxx/projects/qemu/migration/postcopy-ram.c:600: undefined > reference to `__atomic_exchange_8' > /home/maxx/projects/qemu/migration/postcopy-ram.c:609: undefined > reference to `__atomic_exchange_8' > ../migration/postcopy-ram.o: In function `mark_postcopy_blocktime_end': > /home/maxx/projects/qemu/migration/postcopy-ram.c:665: undefined > reference to `__atomic_fetch_add_8' > /home/maxx/projects/qemu/migration/postcopy-ram.c:686: undefined > reference to `__atomic_fetch_add_8' > > Am I doing something wrong? Hmm I also see that with clang on 32bit (gcc is fine); the problem is the postcopy blocktime stuff is doing some 64bit atomics, which you can never be sure 32bit will support. Dave > Max > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK