Re: [Qemu-devel] [PATCH 3/4] docs: Document the l2-cache-full option

[Leonid Bloch]

   On 07/24/2018 06:21 PM, Eric Blake wrote:

     On 07/24/2018 07:17 AM, Leonid Bloch wrote:

     Signed-off-by: Leonid Bloch [1]<address@hidden>
     ---
       docs/qcow2-cache.txt | 12 ++++++++----
       1 file changed, 8 insertions(+), 4 deletions(-)
     diff --git a/docs/qcow2-cache.txt b/docs/qcow2-cache.txt
     index a0a1267482..43c0faaddb 100644
     --- a/docs/qcow2-cache.txt
     +++ b/docs/qcow2-cache.txt
     @@ -110,11 +110,12 @@ How to configure the cache sizes
       Cache sizes can be configured using the -drive option in the
       command-line, or the 'blockdev-add' QMP command.
       -There are three options available, and all of them take bytes:
     +There are four options available:
       -"l2-cache-size":         maximum size of the L2 table cache
     -"refcount-cache-size":   maximum size of the refcount block cache
     -"cache-size":            maximum size of both caches combined
     +"l2-cache-size":         maximum size of the L2 table cache (bytes,
     K, M)
     +"refcount-cache-size":   maximum size of the refcount block cache
     (bytes, K, M)
     +"cache-size":            maximum size of both caches combined
     (bytes, K, M)
     +"l2-cache-full":         make the L2 cache cover the full image
     (boolean)
         There are a few things that need to be taken into account:


     Worth mentioning that the first three can be combined (although
     usually you'll never specify more than 2; as specifying all 3
     requires that you perform the correct addition), but that the third
     is mutually exclusive?

   Actually, only 2 of the first 3 can be specified. But you're right, I
   need to write about mutual exclusivity in the docs. Will fix in v2.
   Thanks!

     @@ -130,6 +131,9 @@ There are a few things that need to be taken
     into account:
          memory as possible to the L2 cache before increasing the
     refcount
          cache size.
       +- If "l2-cache-full" is specified, QEMU will assign enough memory
     +  to the L2 cache to cover the entire size of the image.
     +
       Unlike L2 tables, refcount blocks are not used during normal I/O
     but
       only during allocations and internal snapshots. In most cases they
     are
       accessed sequentially (even during random guest I/O) so increasing
     the

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