On 06/27/2012 10:56 PM, Eric Blake wrote:
> 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.
>
correct, I will fix it.
Orit
