From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:35153) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UJ1TN-0005Wx-8f for qemu-devel@nongnu.org; Fri, 22 Mar 2013 08:53:31 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UJ1TK-0007RB-Ep for qemu-devel@nongnu.org; Fri, 22 Mar 2013 08:53:29 -0400 Received: from [2a02:248:0:30:223:aeff:fefe:7f1c] (port=45968 helo=dns.kamp-intra.net) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UJ1Mf-0005VT-4Q for qemu-devel@nongnu.org; Fri, 22 Mar 2013 08:46:33 -0400 From: Peter Lieven Date: Fri, 22 Mar 2013 13:46:01 +0100 Message-Id: <1363956370-23681-1-git-send-email-pl@kamp.de> Subject: [Qemu-devel] [PATCHv4 0/9] buffer_is_zero / migration optimizations List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: quintela@redhat.com, Stefan Hajnoczi , Peter Lieven , Orit Wasserman , Paolo Bonzini this is v4 of my patch series with various optimizations in zero buffer checking and migration tweaks. thanks especially to Eric Blake for reviewing. v4: - do not inline buffer_find_nonzero_offset() - inline can_usebuffer_find_nonzero_offset() correctly - readd asserts in buffer_find_nonzero_offset() as profiling shows they do not hurt. - change last occurences of scalar 8 by BUFFER_FIND_NONZERO_OFFSET_UNROLL_FACTOR - avoid deferencing p already in patch 5 where we know that the page (p) is zero - explicitly set bytes_sent = 0 if we skip a zero page. bytes_sent was 0 before, but it was not obvious. - add accounting information for skipped zero pages - fix errors reported by checkpatch.pl v3: - remove asserts, inline functions and add a check function if buffer_find_nonzero_offset() can be used. - use above check function in buffer_is_zero() and find_next_bit(). - use buffer_is_nonzero_offset() directly to find zero pages. we know that all requirements are met for memory pages. - fix C89 violation in buffer_is_zero(). - avoid derefencing p in ram_save_block() if we already know the page is zero. - fix initialization of last_offset in reset_ram_globals(). - avoid skipping pages with offset == 0 in bulk stage in migration_bitmap_find_and_reset_dirty(). - compared to v1 check for zero pages also after bulk ram migration as there are guests (e.g. Windows) which zero out large amount of memory while running. v2: - fix description, add trivial zero check and add asserts to buffer_find_nonzero_offset. - add a constant for the unroll factor of buffer_find_nonzero_offset - replace is_dup_page() by buffer_is_zero() - added test results to xbzrle patch - optimize descriptions Peter Lieven (9): move vector definitions to qemu-common.h cutils: add a function to find non-zero content in a buffer buffer_is_zero: use vector optimizations if possible bitops: use vector algorithm to optimize find_next_bit() migration: search for zero instead of dup pages migration: add an indicator for bulk state of ram migration migration: do not sent zero pages in bulk stage migration: do not search dirty pages in bulk stage migration: use XBZRLE only after bulk stage arch_init.c | 74 +++++++++++++++++++---------------------- hmp.c | 2 ++ include/migration/migration.h | 2 ++ include/qemu-common.h | 37 +++++++++++++++++++++ migration.c | 3 +- qapi-schema.json | 6 ++-- qmp-commands.hx | 3 +- util/bitops.c | 24 +++++++++++-- util/cutils.c | 50 ++++++++++++++++++++++++++++ 9 files changed, 155 insertions(+), 46 deletions(-) -- 1.7.9.5