| Message ID | 20200707092117.963394-2-masahiroy@kernel.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v2,1/2] kbuild: introduce ccflags-remove-y and asflags-remove-y | expand |
On Tue, 7 Jul 2020 18:21:17 +0900 Masahiro Yamada <masahiroy@kernel.org> wrote: > ccflags-remove-$(CONFIG_FUNCTION_TRACER) += $(CC_FLAGS_FTRACE) > > exists here in sub-directories of lib/ to keep the behavior of > commit 2464a609ded0 ("ftrace: do not trace library functions"). > > Since that commit, not only the objects in lib/ but also the ones in > the sub-directories are excluded from ftrace (although the commit > description did not explicitly mention this). > > However, most of library functions in sub-directories are not so hot. > Re-add them to ftrace. I'm OK with this change, but note, it wasn't just the hot path that I disabled ftrace on lib for, but some of these calls are done very early at boot up. It may have been PowerPC that I was stumbling over. The issue is that they would call mcount before the kernel was mapped properly, and the system would crash. My PowerPC box no longer boots so I can't test this anymore. But a lot has changed since 2008, and all this may very well be OK. -- Steve
On Tue 2020-07-07 18:21:17, Masahiro Yamada wrote: > ccflags-remove-$(CONFIG_FUNCTION_TRACER) += $(CC_FLAGS_FTRACE) > > exists here in sub-directories of lib/ to keep the behavior of > commit 2464a609ded0 ("ftrace: do not trace library functions"). > > Since that commit, not only the objects in lib/ but also the ones in > the sub-directories are excluded from ftrace (although the commit > description did not explicitly mention this). > > However, most of library functions in sub-directories are not so hot. > Re-add them to ftrace. > > Going forward, only the objects right under lib/ will be excluded. > diff --git a/lib/livepatch/Makefile b/lib/livepatch/Makefile > index 9abdf615b088..295b94bff370 100644 > --- a/lib/livepatch/Makefile > +++ b/lib/livepatch/Makefile > @@ -2,8 +2,6 @@ > # > # Makefile for livepatch test code. > > -ccflags-remove-$(CONFIG_FUNCTION_TRACER) += $(CC_FLAGS_FTRACE) > - > obj-$(CONFIG_TEST_LIVEPATCH) += test_klp_atomic_replace.o \ > test_klp_callbacks_demo.o \ > test_klp_callbacks_demo2.o \ With this change it might be possible to remove also the last few lines that explicitly added $(CC_FLAGS_FTRACE) for two test modules. The two modules really needed these flags. But they are fine also for the other modules. We could do this later as a followup patch but it would be nice to do so here. Best Regards, Petr PS: BTW: The livepatch selftests fail in Linus's master now. But it seems to be for another reason. I am going to dig into it.
On Wed 2020-07-08 08:52:23, Petr Mladek wrote: > > PS: BTW: The livepatch selftests fail in Linus's master now. But it > seems to be for another reason. I am going to dig into it. JFYI, the livepatch selftests are actually working. I have messed the testing here. I am sorry for the noise. Best Regards, Petr
On Wed, Jul 8, 2020 at 1:02 AM Steven Rostedt <rostedt@goodmis.org> wrote: > > On Tue, 7 Jul 2020 18:21:17 +0900 > Masahiro Yamada <masahiroy@kernel.org> wrote: > > > ccflags-remove-$(CONFIG_FUNCTION_TRACER) += $(CC_FLAGS_FTRACE) > > > > exists here in sub-directories of lib/ to keep the behavior of > > commit 2464a609ded0 ("ftrace: do not trace library functions"). > > > > Since that commit, not only the objects in lib/ but also the ones in > > the sub-directories are excluded from ftrace (although the commit > > description did not explicitly mention this). > > > > However, most of library functions in sub-directories are not so hot. > > Re-add them to ftrace. > > I'm OK with this change, but note, it wasn't just the hot path that I > disabled ftrace on lib for, but some of these calls are done very early > at boot up. It may have been PowerPC that I was stumbling over. The > issue is that they would call mcount before the kernel was mapped > properly, and the system would crash. > > My PowerPC box no longer boots so I can't test this anymore. But a lot > has changed since 2008, and all this may very well be OK. > > -- Steve That's why I split this into two commits so that we can do git-bisect and revert the second one in case of a regression. Anyway, we have some more time to test this in linux-next (and somebody reports an issue, if any).
On Wed, Jul 8, 2020 at 6:23 PM Petr Mladek <pmladek@suse.com> wrote: > > On Wed 2020-07-08 08:52:23, Petr Mladek wrote: > > > > PS: BTW: The livepatch selftests fail in Linus's master now. But it > > seems to be for another reason. I am going to dig into it. > > JFYI, the livepatch selftests are actually working. I have messed > the testing here. I am sorry for the noise. > > Best Regards, > Petr No worry, thank you for testing this patch. I deleted the following two lines, otherwise $(CC_FLAGS_FTRACE) would be added twice. # Target modules to be livepatched require CC_FLAGS_FTRACE CFLAGS_test_klp_callbacks_busy.o += $(CC_FLAGS_FTRACE) CFLAGS_test_klp_callbacks_mod.o += $(CC_FLAGS_FTRACE)
On Wed, 22 Jul 2020 11:08:51 +0900 Masahiro Yamada <masahiroy@kernel.org> wrote: > That's why I split this into two commits > so that we can do git-bisect and > revert the second one in case of a regression. > > Anyway, we have some more time to test this in linux-next > (and somebody reports an issue, if any). > You can add my Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> and take it through your tree. -- Steve
diff --git a/lib/842/Makefile b/lib/842/Makefile index b815e824ae37..6f7aad269288 100644 --- a/lib/842/Makefile +++ b/lib/842/Makefile @@ -1,6 +1,3 @@ # SPDX-License-Identifier: GPL-2.0-only - -ccflags-remove-$(CONFIG_FUNCTION_TRACER) += $(CC_FLAGS_FTRACE) - obj-$(CONFIG_842_COMPRESS) += 842_compress.o obj-$(CONFIG_842_DECOMPRESS) += 842_decompress.o diff --git a/lib/crypto/Makefile b/lib/crypto/Makefile index b557ef0b07c2..3a435629d9ce 100644 --- a/lib/crypto/Makefile +++ b/lib/crypto/Makefile @@ -1,7 +1,5 @@ # SPDX-License-Identifier: GPL-2.0 -ccflags-remove-$(CONFIG_FUNCTION_TRACER) += $(CC_FLAGS_FTRACE) - # chacha is used by the /dev/random driver which is always builtin obj-y += chacha.o obj-$(CONFIG_CRYPTO_LIB_CHACHA_GENERIC) += libchacha.o diff --git a/lib/dim/Makefile b/lib/dim/Makefile index 97fc3e89d34e..1d6858a108cb 100644 --- a/lib/dim/Makefile +++ b/lib/dim/Makefile @@ -2,8 +2,6 @@ # DIM Dynamic Interrupt Moderation library # -ccflags-remove-$(CONFIG_FUNCTION_TRACER) += $(CC_FLAGS_FTRACE) - obj-$(CONFIG_DIMLIB) += dim.o dim-y := dim.o net_dim.o rdma_dim.o diff --git a/lib/fonts/Makefile b/lib/fonts/Makefile index f951750c179e..ed95070860de 100644 --- a/lib/fonts/Makefile +++ b/lib/fonts/Makefile @@ -1,8 +1,6 @@ # SPDX-License-Identifier: GPL-2.0 # Font handling -ccflags-remove-$(CONFIG_FUNCTION_TRACER) += $(CC_FLAGS_FTRACE) - font-objs := fonts.o font-objs-$(CONFIG_FONT_SUN8x16) += font_sun8x16.o diff --git a/lib/kunit/Makefile b/lib/kunit/Makefile index 8c847557ab24..724b94311ca3 100644 --- a/lib/kunit/Makefile +++ b/lib/kunit/Makefile @@ -1,6 +1,3 @@ - -ccflags-remove-$(CONFIG_FUNCTION_TRACER) += $(CC_FLAGS_FTRACE) - obj-$(CONFIG_KUNIT) += kunit.o kunit-objs += test.o \ diff --git a/lib/livepatch/Makefile b/lib/livepatch/Makefile index 9abdf615b088..295b94bff370 100644 --- a/lib/livepatch/Makefile +++ b/lib/livepatch/Makefile @@ -2,8 +2,6 @@ # # Makefile for livepatch test code. -ccflags-remove-$(CONFIG_FUNCTION_TRACER) += $(CC_FLAGS_FTRACE) - obj-$(CONFIG_TEST_LIVEPATCH) += test_klp_atomic_replace.o \ test_klp_callbacks_demo.o \ test_klp_callbacks_demo2.o \ diff --git a/lib/lz4/Makefile b/lib/lz4/Makefile index 53da4cab7015..5b42242afaa2 100644 --- a/lib/lz4/Makefile +++ b/lib/lz4/Makefile @@ -1,6 +1,5 @@ # SPDX-License-Identifier: GPL-2.0-only ccflags-y += -O3 -ccflags-remove-$(CONFIG_FUNCTION_TRACER) += $(CC_FLAGS_FTRACE) obj-$(CONFIG_LZ4_COMPRESS) += lz4_compress.o obj-$(CONFIG_LZ4HC_COMPRESS) += lz4hc_compress.o diff --git a/lib/lzo/Makefile b/lib/lzo/Makefile index 9565a555275b..2f58fafbbddd 100644 --- a/lib/lzo/Makefile +++ b/lib/lzo/Makefile @@ -1,6 +1,4 @@ # SPDX-License-Identifier: GPL-2.0-only -ccflags-remove-$(CONFIG_FUNCTION_TRACER) += $(CC_FLAGS_FTRACE) - lzo_compress-objs := lzo1x_compress.o lzo_decompress-objs := lzo1x_decompress_safe.o diff --git a/lib/math/Makefile b/lib/math/Makefile index 49aa50e28185..be6909e943bd 100644 --- a/lib/math/Makefile +++ b/lib/math/Makefile @@ -1,6 +1,4 @@ # SPDX-License-Identifier: GPL-2.0-only -ccflags-remove-$(CONFIG_FUNCTION_TRACER) += $(CC_FLAGS_FTRACE) - obj-y += div64.o gcd.o lcm.o int_pow.o int_sqrt.o reciprocal_div.o obj-$(CONFIG_CORDIC) += cordic.o diff --git a/lib/mpi/Makefile b/lib/mpi/Makefile index df7883521619..d5874a7f5ff9 100644 --- a/lib/mpi/Makefile +++ b/lib/mpi/Makefile @@ -3,8 +3,6 @@ # MPI multiprecision maths library (from gpg) # -ccflags-remove-$(CONFIG_FUNCTION_TRACER) += $(CC_FLAGS_FTRACE) - obj-$(CONFIG_MPILIB) = mpi.o mpi-y = \ diff --git a/lib/raid6/Makefile b/lib/raid6/Makefile index 3482d6ae3f3b..b4c0df6d706d 100644 --- a/lib/raid6/Makefile +++ b/lib/raid6/Makefile @@ -1,7 +1,4 @@ # SPDX-License-Identifier: GPL-2.0 - -ccflags-remove-$(CONFIG_FUNCTION_TRACER) += $(CC_FLAGS_FTRACE) - obj-$(CONFIG_RAID6_PQ) += raid6_pq.o raid6_pq-y += algos.o recov.o tables.o int1.o int2.o int4.o \ diff --git a/lib/reed_solomon/Makefile b/lib/reed_solomon/Makefile index a5c9defdac7f..5d4fa68f26cb 100644 --- a/lib/reed_solomon/Makefile +++ b/lib/reed_solomon/Makefile @@ -3,7 +3,5 @@ # This is a modified version of reed solomon lib, # -ccflags-remove-$(CONFIG_FUNCTION_TRACER) += $(CC_FLAGS_FTRACE) - obj-$(CONFIG_REED_SOLOMON) += reed_solomon.o obj-$(CONFIG_REED_SOLOMON_TEST) += test_rslib.o diff --git a/lib/xz/Makefile b/lib/xz/Makefile index fae9b6c7c389..fa6af814a8d1 100644 --- a/lib/xz/Makefile +++ b/lib/xz/Makefile @@ -1,7 +1,4 @@ # SPDX-License-Identifier: GPL-2.0-only - -ccflags-remove-$(CONFIG_FUNCTION_TRACER) += $(CC_FLAGS_FTRACE) - obj-$(CONFIG_XZ_DEC) += xz_dec.o xz_dec-y := xz_dec_syms.o xz_dec_stream.o xz_dec_lzma2.o xz_dec-$(CONFIG_XZ_DEC_BCJ) += xz_dec_bcj.o diff --git a/lib/zlib_deflate/Makefile b/lib/zlib_deflate/Makefile index 1fcefe73536f..2622e03c0b94 100644 --- a/lib/zlib_deflate/Makefile +++ b/lib/zlib_deflate/Makefile @@ -7,8 +7,6 @@ # decompression code. # -ccflags-remove-$(CONFIG_FUNCTION_TRACER) += $(CC_FLAGS_FTRACE) - obj-$(CONFIG_ZLIB_DEFLATE) += zlib_deflate.o zlib_deflate-objs := deflate.o deftree.o deflate_syms.o diff --git a/lib/zlib_dfltcc/Makefile b/lib/zlib_dfltcc/Makefile index 7a8067f6e772..8e4d5afbbb10 100644 --- a/lib/zlib_dfltcc/Makefile +++ b/lib/zlib_dfltcc/Makefile @@ -6,8 +6,6 @@ # This is the code for s390 zlib hardware support. # -ccflags-remove-$(CONFIG_FUNCTION_TRACER) += $(CC_FLAGS_FTRACE) - obj-$(CONFIG_ZLIB_DFLTCC) += zlib_dfltcc.o zlib_dfltcc-objs := dfltcc.o dfltcc_deflate.o dfltcc_inflate.o dfltcc_syms.o diff --git a/lib/zlib_inflate/Makefile b/lib/zlib_inflate/Makefile index a451e96f9845..27327d3e9f54 100644 --- a/lib/zlib_inflate/Makefile +++ b/lib/zlib_inflate/Makefile @@ -14,8 +14,6 @@ # uncompression can be done without blocking on allocation). # -ccflags-remove-$(CONFIG_FUNCTION_TRACER) += $(CC_FLAGS_FTRACE) - obj-$(CONFIG_ZLIB_INFLATE) += zlib_inflate.o zlib_inflate-objs := inffast.o inflate.o infutil.o \ diff --git a/lib/zstd/Makefile b/lib/zstd/Makefile index 01be908a2d94..f5d778e7e5c7 100644 --- a/lib/zstd/Makefile +++ b/lib/zstd/Makefile @@ -3,7 +3,6 @@ obj-$(CONFIG_ZSTD_COMPRESS) += zstd_compress.o obj-$(CONFIG_ZSTD_DECOMPRESS) += zstd_decompress.o ccflags-y += -O3 -ccflags-remove-$(CONFIG_FUNCTION_TRACER) += $(CC_FLAGS_FTRACE) zstd_compress-y := fse_compress.o huf_compress.o compress.o \ entropy_common.o fse_decompress.o zstd_common.o
ccflags-remove-$(CONFIG_FUNCTION_TRACER) += $(CC_FLAGS_FTRACE) exists here in sub-directories of lib/ to keep the behavior of commit 2464a609ded0 ("ftrace: do not trace library functions"). Since that commit, not only the objects in lib/ but also the ones in the sub-directories are excluded from ftrace (although the commit description did not explicitly mention this). However, most of library functions in sub-directories are not so hot. Re-add them to ftrace. Going forward, only the objects right under lib/ will be excluded. Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> --- Changes in v2: - New patch lib/842/Makefile | 3 --- lib/crypto/Makefile | 2 -- lib/dim/Makefile | 2 -- lib/fonts/Makefile | 2 -- lib/kunit/Makefile | 3 --- lib/livepatch/Makefile | 2 -- lib/lz4/Makefile | 1 - lib/lzo/Makefile | 2 -- lib/math/Makefile | 2 -- lib/mpi/Makefile | 2 -- lib/raid6/Makefile | 3 --- lib/reed_solomon/Makefile | 2 -- lib/xz/Makefile | 3 --- lib/zlib_deflate/Makefile | 2 -- lib/zlib_dfltcc/Makefile | 2 -- lib/zlib_inflate/Makefile | 2 -- lib/zstd/Makefile | 1 - 17 files changed, 36 deletions(-)