On 06/27/2012 04:34 AM, Orit Wasserman wrote: > In the outgoing migration check to see if the page is cached and > changed than send compressed page by using save_xbrle_page function. > In the incoming migration check to see if RAM_SAVE_FLAG_XBRLE is set > and decompress the page (by using load_xbrle function).
Mismatch between commit comment and actual code (XBRLE vs. XBZRLE).
> +
> + /* Stage 1 cache the page and exit.
> + Stage 2 check to see if page is cached , if not cache the page.
s/cached ,/cached,/
> + if (encoded_len == 0) {
> + DPRINTF("Unmodifed page skipping\n");
spelling and grammar:
s/Unmodifed page skipping/Skipping unmodified page/
> if (!block)
> block = QLIST_FIRST(&ram_list.blocks);
>
> +
> +
> do {
Why the spurious whitespace addition?
> + } else if (migrate_use_xbzrle() && stage != 3) {
> + current_addr = block->offset + offset;
> + /* In stage 1 we only cache the pages before sending them
> + from the cache (uncompressed).
> + We doen't use compression for stage 3.
s/doen't/don't/
> +
> + /* either we didn't send yet (we may got XBZRLE overflow) */
s/may got/may have had/
>
> - break;
> + /* if page is unmodified lets continue to the next */
s/lets/let's/
or even shorter:
s/ lets/,/
> @@ -331,6 +440,17 @@ int ram_save_live(QEMUFile *f, int stage, void *opaque)
> last_offset = 0;
> sort_ram_list();
>
> + if (migrate_use_xbzrle()) {
> + XBZRLE.cache = cache_init(migrate_xbzrle_cache_size() /
> + TARGET_PAGE_SIZE,
> + TARGET_PAGE_SIZE);
> + if (!XBZRLE.cache) {
> + DPRINTF("Error creating cache\n");
> + return -1;
> + }
> + XBZRLE.encoded_buf = g_malloc0(TARGET_PAGE_SIZE);
This guarantees long alignment (good, per my proposed g_assert in
10/13), but not page alignment. Do we get any benefits by using a
different allocation to guarantee page alignment? (Off-hand, I'm not
thinking of any.)
> @@ -389,7 +509,7 @@ int ram_save_live(QEMUFile *f, int stage, void *opaque)
> while ((bytes_sent = ram_save_block(f, stage)) != -1) {
> bytes_transferred += bytes_sent;
> }
> - memory_global_dirty_log_stop();
> + migration_end();
> }
>
> qemu_put_be64(f, RAM_SAVE_FLAG_EOS);
This hunk should have been squashed into 9/13.
> @@ -512,6 +675,16 @@ int ram_load(QEMUFile *f, void *opaque, int version_id)
> host = host_from_stream_offset(f, addr, flags);
>
> qemu_get_buffer(f, host, TARGET_PAGE_SIZE);
> + } else if (flags & RAM_SAVE_FLAG_XBZRLE) {
We should probably be erroring out if we detect this incoming flag, but
the management app explicitly disabled the xbzrle migration capability,
since that represents a case of user error, and failing the migration is
better than proceeding to decode things anyway.
--
Eric Blake ebl...@redhat.com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
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