diff --git a/swh/loader/mercurial/from_disk.py b/swh/loader/mercurial/from_disk.py
--- a/swh/loader/mercurial/from_disk.py
+++ b/swh/loader/mercurial/from_disk.py
@@ -10,6 +10,7 @@
 from typing import Any, Dict, List, Optional, Union
 
 import dateutil
+from mercurial.util import lrucachedict  # type: ignore
 
 from swh.core.config import merge_configs
 from swh.loader.core.loader import BaseLoader
@@ -116,6 +117,11 @@
         self._repo: Optional[hgutil.Repository] = None
         self.revision_nodeid_to_swhid: Dict[HgNodeId, Sha1Git] = {}
 
+        # Cache the content hash across revisions to avoid recalculation.
+        self.content_hash_cache: lrucachedict = lrucachedict(
+            self.config["content_cache_size"],
+        )
+
     @property
     def repo(self) -> hgutil.Repository:
         """ An filtered mercurial repository.
@@ -336,7 +342,17 @@
         rev_ctx = self.repo[hg_nodeid]
         file_ctx = rev_ctx[file_path]
 
+        file_nodeid = file_ctx._fileid
         perms = FLAG_PERMS[file_ctx.flags()]
+
+        # Key is file_nodeid + perms because permissions does not participate
+        # in content hash in hg while it is the case in swh.
+        cache_key = (file_nodeid, perms)
+
+        sha1_git = self.content_hash_cache.get(cache_key)
+        if sha1_git is not None:
+            return Content({"sha1_git": sha1_git, "perms": perms})
+
         data = file_ctx.data()
 
         content_data = MultiHash.from_data(data).digest()
@@ -355,6 +371,8 @@
                 "produced {type(model)!r} instead of {ModelContent!r}"
             )
 
+        self.content_hash_cache[cache_key] = content.hash
+
         return content
 
     def store_directories(self, hg_nodeid: HgNodeId) -> Sha1Git: