On 03/01/2018 06:43 PM, Li Zhijian wrote:
this patch is to fix running userfaultfd_hugetlb failed on the host which has
more than 64 cpus
running userfaultfd_hugetlb
invalid MiB
Usage: <MiB> <bounces>
[FAIL]
From userfaultfd.c we can know, hugetlb_size need to meet hugetlb_size >= nr_cpus * hugepage_size
hugepage_size is often 2M, so when host cpus > 64, it requires more than 128M.
Signed-off-by: Li Zhijian zhijianx.li@intel.com
Thanks for fixing this.
tools/testing/selftests/vm/run_vmtests | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/tools/testing/selftests/vm/run_vmtests b/tools/testing/selftests/vm/run_vmtests
index d2561895a021a..c440fb972afe9 100755
--- a/tools/testing/selftests/vm/run_vmtests
+++ b/tools/testing/selftests/vm/run_vmtests
@@ -2,8 +2,6 @@
 # SPDX-License-Identifier: GPL-2.0
 #please run as root
 
-#we need 256M, below is the size in kB
-needmem=262144
 mnt=./huge
 exitcode=0
 
@@ -17,6 +15,13 @@ while read name size unit; do
   fi
 done < /proc/meminfo
 
+nr_cpus=$(nproc)
+pgsize_MB=$((pgsize/1024))
+# rule: nr_cpus * pgsize_MB <= hugetlb_size(round to 128M for testing)
+hugetlb_size=$((((nr_cpus*pgsize_MB+127)/128)*128))
+# needmem depends on the nr_cpus, below is the size in kB
+needmem=$((hugetlb_size*2*1024))
#set proper nr_hugepages
 if [ -n "$freepgs" ] && [ -n "$pgsize" ]; then
   nr_hugepgs=`cat /proc/sys/vm/nr_hugepages`
@@ -107,8 +112,8 @@ fi
 echo "---------------------------"
 echo "running userfaultfd_hugetlb"
 echo "---------------------------"
-# 256MB total huge pages == 128MB src and 128MB dst
-./userfaultfd hugetlb 128 32 $mnt/ufd_test_file
+# 256MB total huge pages == 128MB src and 128MB dst when nr_cpus <= 64
+./userfaultfd hugetlb $hugetlb_size 32 $mnt/ufd_test_file
 if [ $? -ne 0 ]; then
   echo "[FAIL]"
   exitcode=1
The above changes are functionally OK.  But, I think something like the
following may be easier to read/understand.  Feel free to use as much or
little as you would like.
-- 
Mike Kravetz
Signed-off-by: Mike Kravetz 
mike.kravetz@oracle.com
---
 tools/testing/selftests/vm/run_vmtests | 25 +++++++++++++++++--------
 1 file changed, 17 insertions(+), 8 deletions(-)
diff --git a/tools/testing/selftests/vm/run_vmtests b/tools/testing/selftests/vm/run_vmtests
index d2561895a021..40671f6739a9 100755
--- a/tools/testing/selftests/vm/run_vmtests
+++ b/tools/testing/selftests/vm/run_vmtests
@@ -2,25 +2,33 @@
 # SPDX-License-Identifier: GPL-2.0
 #please run as root
-#we need 256M, below is the size in kB
-needmem=262144
 mnt=./huge
 exitcode=0
-#get pagesize and freepages from /proc/meminfo
+#get huge pagesize and freepages from /proc/meminfo
 while read name size unit; do
    if [ "$name" = "HugePages_Free:" ]; then
    	freepgs=$size
    fi
    if [ "$name" = "Hugepagesize:" ]; then
-		pgsize=$size
+		hpgsize_KB=$size
    fi
 done < /proc/meminfo
+# Simple hugetlbfs tests have a hardcoded minimum requirement of
+# huge pages totaling 256MB (262144KB) in size.  The userfaultfd
+# hugetlb test requires a minimum of 2 * nr_cpus huge pages.  Take
+# both of these requirements into account and attempt to increase
+* number of huge pages available.
+nr_cpus=$(nproc)
+hpgsize_MB=$((hpgsize_KB / 1024))
+half_ufd_size_MB=$((((nr_cpus * hpgsize_MB + 127) / 128) * 128))
+needmem_KB=$((half_ufd_size_MB * 2 * 1024))
+
 #set proper nr_hugepages
-if [ -n "$freepgs" ] && [ -n "$pgsize" ]; then
+if [ -n "$freepgs" ] && [ -n "$hpgsize_KB" ]; then
    nr_hugepgs=`cat /proc/sys/vm/nr_hugepages`
-	needpgs=`expr $needmem / $pgsize`
+	needpgs=$((needmem_KB / hpgsize_KB))
    tries=2
    while [ $tries -gt 0 ] && [ $freepgs -lt $needpgs ]; do
    	lackpgs=$(( $needpgs - $freepgs ))
@@ -107,8 +115,9 @@ fi
 echo "---------------------------"
 echo "running userfaultfd_hugetlb"
 echo "---------------------------"
-# 256MB total huge pages == 128MB src and 128MB dst
-./userfaultfd hugetlb 128 32 $mnt/ufd_test_file
+# Test requires source and destination huge pages.  Size of source
+# (half_ufd_size_MB) is passed as argument to test.
+./userfaultfd hugetlb $half_ufd_size_MB 32 $mnt/ufd_test_file
 if [ $? -ne 0 ]; then
    echo "[FAIL]"
    exitcode=1
-- 
2.13.6
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