On Sun, Sep 27, 2020 at 11:21:59PM -0700, John Hubbard wrote: > @@ -76,8 +79,6 @@ TEST_FILES := test_vmalloc.sh > KSFT_KHDR_INSTALL := 1 > include ../lib.mk > > -$(OUTPUT)/hmm-tests: LDLIBS += -lhugetlbfs > - > ifeq ($(ARCH),x86_64) > BINARIES_32 := $(patsubst %,$(OUTPUT)/%,$(BINARIES_32)) > BINARIES_64 := $(patsubst %,$(OUTPUT)/%,$(BINARIES_64)) > @@ -130,3 +131,22 @@ endif > $(OUTPUT)/mlock-random-test: LDLIBS += -lcap > > $(OUTPUT)/gup_test: ../../../../mm/gup_test.h > + > +$(OUTPUT)/hmm-tests: local_config.h > + > +# HMM_EXTRA_LIBS may get set in local_config.mk, or it may be left empty. > +$(OUTPUT)/hmm-tests: LDLIBS += $(HMM_EXTRA_LIBS) > + > +local_config.mk local_config.h: check_config.sh > + ./check_config.sh > + > +EXTRA_CLEAN += local_config.mk local_config.h > + > +ifeq ($(HMM_EXTRA_LIBS),) > +all: warn_missing_hugelibs > + > +warn_missing_hugelibs: > + @echo ; \ > + echo "Warning: missing libhugetlbfs support. Some HMM tests will be skipped." ; \ > + echo > +endif > diff --git a/tools/testing/selftests/vm/check_config.sh b/tools/testing/selftests/vm/check_config.sh > new file mode 100755 > index 000000000000..651a4b192479 > +++ b/tools/testing/selftests/vm/check_config.sh > @@ -0,0 +1,30 @@ > +#!/bin/sh > +# SPDX-License-Identifier: GPL-2.0 > +# > +# Probe for libraries and create header files to record the results. Both C > +# header files and Makefile include fragments are created. > + > +OUTPUT_H_FILE=local_config.h > +OUTPUT_MKFILE=local_config.mk > + > +# libhugetlbfs > +tmpname=$(mktemp) > +tmpfile_c=${tmpname}.c > +tmpfile_o=${tmpname}.o > + > +echo "#include <sys/types.h>" > $tmpfile_c > +echo "#include <hugetlbfs.h>" >> $tmpfile_c > +echo "int func(void) { return 0; }" >> $tmpfile_c > + > +gcc -c $tmpfile_c -o $tmpfile_o >/dev/null 2>&1 This gcc has to come from some makefile variable This is kind of janky :\ Could we just not use libhugetlbfs? Doesn't it all just boil down to creating a file in /dev/huge? Eg look at tools/testing/selftests/vm/hugepage-mmap.c Jason