LU-10239 osc: limit chunk number of write submit

[fs/lustre-release.git] / lustre / osc / osc_cache.c

diff --git a/lustre/osc/osc_cache.c b/lustre/osc/osc_cache.c
index 5394a75..4660212 100644 (file)
--- a/lustre/osc/osc_cache.c
+++ b/lustre/osc/osc_cache.c
@@ -1991,36 +1991,6 @@ static int try_to_add_extent_for_io(struct client_obd *cli,
        RETURN(1);
 }
 
        RETURN(1);
 }
 

-static inline unsigned osc_max_write_chunks(const struct client_obd *cli)
-{
-       /*
-        * LU-8135:
-        *
-        * The maximum size of a single transaction is about 64MB in ZFS.
-        * #define DMU_MAX_ACCESS (64 * 1024 * 1024)
-        *
-        * Since ZFS is a copy-on-write file system, a single dirty page in
-        * a chunk will result in the rewrite of the whole chunk, therefore
-        * an RPC shouldn't be allowed to contain too many chunks otherwise
-        * it will make transaction size much bigger than 64MB, especially
-        * with big block size for ZFS.
-        *
-        * This piece of code is to make sure that OSC won't send write RPCs
-        * with too many chunks. The maximum chunk size that an RPC can cover
-        * is set to PTLRPC_MAX_BRW_SIZE, which is defined to 16MB. Ideally
-        * OST should tell the client what the biggest transaction size is,
-        * but it's good enough for now.
-        *
-        * This limitation doesn't apply to ldiskfs, which allows as many
-        * chunks in one RPC as we want. However, it won't have any benefits
-        * to have too many discontiguous pages in one RPC.
-        *
-        * An osc_extent won't cover over a RPC size, so the chunks in an
-        * osc_extent won't bigger than PTLRPC_MAX_BRW_SIZE >> chunkbits.
-        */
-       return PTLRPC_MAX_BRW_SIZE >> cli->cl_chunkbits;
-}
-

 /**
  * In order to prevent multiple ptlrpcd from breaking contiguous extents,
  * get_write_extent() takes all appropriate extents in atomic.
 /**
  * In order to prevent multiple ptlrpcd from breaking contiguous extents,
  * get_write_extent() takes all appropriate extents in atomic.