| Message ID | 1395145464-5524-11-git-send-email-arei.gonglei@huawei.com |
|---|---|
| State | New |
| Headers | show |
On 03/18/2014 06:24 AM, arei.gonglei@huawei.com wrote: > From: ChenLiang <chenliang88@huawei.com> > > update the doc of XBZRLE Having the subject line and the body of the commit message be identical is redundant. And just by looking at the commit message, I can't see WHY you are updating things. If you were to keep this as a separate commit, I'd suggest it look more like: XBZRLE: document cache miss policy Add a section to the XBZRLE documentation describing how the page cache determines which pages are hot. That said, I think you should squash this documentation update into patch 5/10 where you actually implement it, so that a single patch becomes self-documenting why you went with this design. At which point, the combined patch commit message should look something like: XBZRLE: optimize XBZRLE to decrease cache misses ...existing text from 5/10... Additionally, document the new cache age policy. > > Signed-off-by: ChenLiang <chenliang88@huawei.com> > Signed-off-by: Gonglei <arei.gonglei@huawei.com> > --- > docs/xbzrle.txt | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/docs/xbzrle.txt b/docs/xbzrle.txt > index cc3a26a..cdf1e3e 100644 > --- a/docs/xbzrle.txt > +++ b/docs/xbzrle.txt > @@ -71,6 +71,13 @@ encoded buffer: > encoded length 24 > e9 07 0f 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f 03 01 67 01 01 69 > > +The strategy of updating cache > +================================= Copy-and-paste from bad examples already in this file, but it's nicer when the length of ==== matches the heading it is paired with. > +Keeping the hot page in cache is effective to decrease cache missing. > +XBZRLE use a counter as the age of page. The counter will increase > +after the ram dirty bitmap syncing. When cache conflicts XBZRLE only > +replace the old page in cache. Suggestions for better grammar: Cache update strategy ===================== Keeping the hot pages in the cache is effective for decreased cache misses. XBZRLE uses a counter as the age of each page. The counter will increase after each ram dirty bitmap sync. When a cache conflict is detected, XBZRLE will only evict pages in the cache that are older than a threshold.
diff --git a/docs/xbzrle.txt b/docs/xbzrle.txt index cc3a26a..cdf1e3e 100644 --- a/docs/xbzrle.txt +++ b/docs/xbzrle.txt @@ -71,6 +71,13 @@ encoded buffer: encoded length 24 e9 07 0f 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f 03 01 67 01 01 69 +The strategy of updating cache +================================= +Keeping the hot page in cache is effective to decrease cache missing. +XBZRLE use a counter as the age of page. The counter will increase +after the ram dirty bitmap syncing. When cache conflicts XBZRLE only +replace the old page in cache. + Usage ====================== 1. Verify the destination QEMU version is able to decode the new format.