From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:58949) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SuB0I-0003Zx-8T for qemu-devel@nongnu.org; Wed, 25 Jul 2012 19:28:31 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1SuB0G-0002y3-Um for qemu-devel@nongnu.org; Wed, 25 Jul 2012 19:28:30 -0400 Received: from mail-pb0-f45.google.com ([209.85.160.45]:38656) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SuB0G-0002xx-MV for qemu-devel@nongnu.org; Wed, 25 Jul 2012 19:28:28 -0400 Received: by pbbro12 with SMTP id ro12so2107277pbb.4 for ; Wed, 25 Jul 2012 16:28:27 -0700 (PDT) Sender: fluxion Date: Wed, 25 Jul 2012 18:27:57 -0500 From: Michael Roth Message-ID: <20120725232757.GB2708@illuin> References: <1343155012-26316-1-git-send-email-quintela@redhat.com> <1343155012-26316-5-git-send-email-quintela@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1343155012-26316-5-git-send-email-quintela@redhat.com> Subject: Re: [Qemu-devel] [PATCH 04/27] add a version number to ram_list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Juan Quintela Cc: Paolo Bonzini , Umesh Deshpande , qemu-devel@nongnu.org On Tue, Jul 24, 2012 at 08:36:29PM +0200, Juan Quintela wrote: > From: Umesh Deshpande > > This will be used to detect if last_block might have become invalid > across different calls to ram_save_live. > > Signed-off-by: Paolo Bonzini > Signed-off-by: Umesh Deshpande > Signed-off-by: Juan Quintela > --- > arch_init.c | 6 ++++++ > cpu-all.h | 1 + > exec.c | 4 ++++ > 3 files changed, 11 insertions(+) > > diff --git a/arch_init.c b/arch_init.c > index 02d36ce..9e05aae 100644 > --- a/arch_init.c > +++ b/arch_init.c > @@ -340,6 +340,7 @@ static int save_xbzrle_page(QEMUFile *f, uint8_t *current_data, > > static RAMBlock *last_block; > static ram_addr_t last_offset; > +static uint32_t last_version; > > /* > * ram_save_block: Writes a page of memory to the stream f > @@ -496,6 +497,7 @@ static void reset_ram_globals(void) > { > last_block = NULL; > last_offset = 0; > + last_version = ram_list.version; > sort_ram_list(); > } > > @@ -554,6 +556,10 @@ static int ram_save_iterate(QEMUFile *f, void *opaque) > int i; > uint64_t expected_time; > > + if (ram_list.version != last_version) { > + reset_ram_globals(); > + } > + Was it a bug in the old code to not do this? In the unthreaded version it looks like last_block could still become invalid between iterations if it was removed in the meantime, so I'm trying to understand why it's needed now. And why do we re-sort when this happens? The old implementation didn't seem to place any guarantees on the block ordering beyond the initial sorting by block->idstr. After that they were sent in MRU order. > bytes_transferred_last = bytes_transferred; > bwidth = qemu_get_clock_ns(rt_clock); > > diff --git a/cpu-all.h b/cpu-all.h > index ca3bb24..429b2c6 100644 > --- a/cpu-all.h > +++ b/cpu-all.h > @@ -486,6 +486,7 @@ typedef struct RAMBlock { > > typedef struct RAMList { > uint8_t *phys_dirty; > + uint32_t version; > QLIST_HEAD(, RAMBlock) blocks_mru; > QLIST_HEAD(, RAMBlock) blocks; > uint64_t dirty_pages; > diff --git a/exec.c b/exec.c > index afc472f..ceffa4f 100644 > --- a/exec.c > +++ b/exec.c > @@ -2555,6 +2555,8 @@ ram_addr_t qemu_ram_alloc_from_ptr(ram_addr_t size, void *host, > QLIST_INSERT_HEAD(&ram_list.blocks, new_block, next); > QLIST_INSERT_HEAD(&ram_list.blocks_mru, new_block, next_mru); > > + ram_list.version++; > + > ram_list.phys_dirty = g_realloc(ram_list.phys_dirty, > last_ram_offset() >> TARGET_PAGE_BITS); > cpu_physical_memory_set_dirty_range(new_block->offset, size, 0xff); > @@ -2578,6 +2580,7 @@ void qemu_ram_free_from_ptr(ram_addr_t addr) > if (addr == block->offset) { > QLIST_REMOVE(block, next); > QLIST_REMOVE(block, next_mru); > + ram_list.version++; > g_free(block); > return; > } > @@ -2592,6 +2595,7 @@ void qemu_ram_free(ram_addr_t addr) > if (addr == block->offset) { > QLIST_REMOVE(block, next); > QLIST_REMOVE(block, next_mru); > + ram_list.version++; > if (block->flags & RAM_PREALLOC_MASK) { > ; > } else if (mem_path) { > -- > 1.7.10.4 > >