diff --git a/.github/workflows/db_bench-avx512-run.yml b/.github/workflows/db_bench-avx512-run.yml
index 1f588e10d..079cc3bc6 100644
--- a/.github/workflows/db_bench-avx512-run.yml
+++ b/.github/workflows/db_bench-avx512-run.yml
@@ -76,12 +76,14 @@ jobs:
           test -x "$RUN_PREFIX/rocksdb-master/bin/db_bench"
           echo "RUN_PREFIX=$RUN_PREFIX" >> "$GITHUB_ENV"
 
-      - name: Probe /dev/shm
+      - name: Resize /dev/shm to 75% of physical memory
         run: |
           set -xe
           # Engines rotate exclusive use of /dev/shm (one DB at a time).
           # Do not pre-create all three DB dirs here.
           df -h /dev/shm
+          sudo mount -o remount,size=75% /dev/shm
+          df -h /dev/shm
 
       - name: Run ToplingDB benches
         run: |
diff --git a/.github/workflows/db_bench-dcompact-run.yml b/.github/workflows/db_bench-dcompact-run.yml
index 1996c201e..a23fcfe90 100644
--- a/.github/workflows/db_bench-dcompact-run.yml
+++ b/.github/workflows/db_bench-dcompact-run.yml
@@ -106,6 +106,8 @@ jobs:
           test -x "$RUN_PREFIX/rocksdb-master/bin/remote_compact_worker"
           echo "RUN_PREFIX=$RUN_PREFIX" >> "$GITHUB_ENV"
           df -h /dev/shm
+          sudo mount -o remount,size=75% /dev/shm
+          df -h /dev/shm
 
       - name: Compute RocksDB cache_size
         run: |
diff --git a/.github/workflows/db_bench-run.yml b/.github/workflows/db_bench-run.yml
index 0d213712b..2df45b363 100644
--- a/.github/workflows/db_bench-run.yml
+++ b/.github/workflows/db_bench-run.yml
@@ -102,12 +102,14 @@ jobs:
           test -x "$RUN_PREFIX/rocksdb-master/bin/db_bench"
           echo "RUN_PREFIX=$RUN_PREFIX" >> "$GITHUB_ENV"
 
-      - name: Probe /dev/shm
+      - name: Resize /dev/shm to 75% of physical memory
         run: |
           set -xe
           # Engines rotate exclusive use of /dev/shm (one DB at a time).
           # Do not pre-create all three DB dirs here.
           df -h /dev/shm
+          sudo mount -o remount,size=75% /dev/shm
+          df -h /dev/shm
 
       - name: Run ToplingDB benches
         run: |