| Message ID | a1d31f84ddb0926813b17fcd5cc7f3fa7b4deac2.1602759123.git.christophe.leroy@csgroup.eu (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 328e7e487a464aad024fbde6663b7859df082b7b |
| Headers | show |
| Series | powerpc: force inlining of csum_partial() to avoid multiple csum_partial() with GCC10 | expand |
| Context | Check | Description |
|---|---|---|
| snowpatch_ozlabs/apply_patch | success | Successfully applied on branch powerpc/merge (118be7377c97e35c33819bcb3bbbae5a42a4ac43) |
| snowpatch_ozlabs/build-ppc64le | warning | Upstream build failed, couldn't test patch |
| snowpatch_ozlabs/build-ppc64be | warning | Upstream build failed, couldn't test patch |
| snowpatch_ozlabs/build-ppc64e | warning | Upstream build failed, couldn't test patch |
| snowpatch_ozlabs/build-pmac32 | warning | Upstream build failed, couldn't test patch |
| snowpatch_ozlabs/checkpatch | warning | total: 0 errors, 1 warnings, 0 checks, 8 lines checked |
| snowpatch_ozlabs/needsstable | success | Patch has no Fixes tags |
Hi! On Thu, Oct 15, 2020 at 10:52:20AM +0000, Christophe Leroy wrote: > With gcc9 I get: <snip> > With gcc10 I get: <snip> > gcc10 defines multiple versions of csum_partial() which are just > an unconditionnal branch to __csum_partial(). It doesn't inline it, yes. Could you open a GCC PR for this please? > To enforce inlining of that branch to __csum_partial(), > mark csum_partial() as __always_inline. That should be fine of course, but it would be good if we could fix this in the compiler :-) Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org> Segher
Le 15/10/2020 à 15:25, Segher Boessenkool a écrit : > Hi! > > On Thu, Oct 15, 2020 at 10:52:20AM +0000, Christophe Leroy wrote: >> With gcc9 I get: > > <snip> > >> With gcc10 I get: > > <snip> > >> gcc10 defines multiple versions of csum_partial() which are just >> an unconditionnal branch to __csum_partial(). > > It doesn't inline it, yes. > > Could you open a GCC PR for this please? Sure. I also have get_order() 75 times in my vmlinux, all the same as the following: c0016790 <get_order>: c0016790: 38 63 ff ff addi r3,r3,-1 c0016794: 54 63 a3 3e rlwinm r3,r3,20,12,31 c0016798: 7c 63 00 34 cntlzw r3,r3 c001679c: 20 63 00 20 subfic r3,r3,32 c00167a0: 4e 80 00 20 blr Christophe
Le 15/10/2020 à 15:25, Segher Boessenkool a écrit : > Hi! > > On Thu, Oct 15, 2020 at 10:52:20AM +0000, Christophe Leroy wrote: >> With gcc9 I get: > > <snip> > >> With gcc10 I get: > > <snip> > >> gcc10 defines multiple versions of csum_partial() which are just >> an unconditionnal branch to __csum_partial(). > > It doesn't inline it, yes. > > Could you open a GCC PR for this please? > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97445 Christophe
On Thu, 15 Oct 2020 10:52:20 +0000 (UTC), Christophe Leroy wrote: > ppc-linux-objdump -d vmlinux | grep -e "<csum_partial>" -e "<__csum_partial>" > > With gcc9 I get: > > c0017ef8 <__csum_partial>: > c00182fc: 4b ff fb fd bl c0017ef8 <__csum_partial> > c0018478: 4b ff fa 80 b c0017ef8 <__csum_partial> > c03e8458: 4b c2 fa a0 b c0017ef8 <__csum_partial> > c03e8518: 4b c2 f9 e1 bl c0017ef8 <__csum_partial> > c03ef410: 4b c2 8a e9 bl c0017ef8 <__csum_partial> > c03f0b24: 4b c2 73 d5 bl c0017ef8 <__csum_partial> > c04279a4: 4b bf 05 55 bl c0017ef8 <__csum_partial> > c0429820: 4b be e6 d9 bl c0017ef8 <__csum_partial> > c0429944: 4b be e5 b5 bl c0017ef8 <__csum_partial> > c042b478: 4b be ca 81 bl c0017ef8 <__csum_partial> > c042b554: 4b be c9 a5 bl c0017ef8 <__csum_partial> > c045f15c: 4b bb 8d 9d bl c0017ef8 <__csum_partial> > c0492190: 4b b8 5d 69 bl c0017ef8 <__csum_partial> > c0492310: 4b b8 5b e9 bl c0017ef8 <__csum_partial> > c0495594: 4b b8 29 65 bl c0017ef8 <__csum_partial> > c049c420: 4b b7 ba d9 bl c0017ef8 <__csum_partial> > c049c870: 4b b7 b6 89 bl c0017ef8 <__csum_partial> > c049c930: 4b b7 b5 c9 bl c0017ef8 <__csum_partial> > c04a9ca0: 4b b6 e2 59 bl c0017ef8 <__csum_partial> > c04bdde4: 4b b5 a1 15 bl c0017ef8 <__csum_partial> > c04be480: 4b b5 9a 79 bl c0017ef8 <__csum_partial> > c04be710: 4b b5 97 e9 bl c0017ef8 <__csum_partial> > c04c969c: 4b b4 e8 5d bl c0017ef8 <__csum_partial> > c04ca2fc: 4b b4 db fd bl c0017ef8 <__csum_partial> > c04cf5bc: 4b b4 89 3d bl c0017ef8 <__csum_partial> > c04d0440: 4b b4 7a b9 bl c0017ef8 <__csum_partial> > > [...] Applied to powerpc/next. [1/1] powerpc: force inlining of csum_partial() to avoid multiple csum_partial() with GCC10 https://git.kernel.org/powerpc/c/328e7e487a464aad024fbde6663b7859df082b7b cheers
diff --git a/arch/powerpc/include/asm/checksum.h b/arch/powerpc/include/asm/checksum.h index 9cce06194dcc..cab8fec60005 100644 --- a/arch/powerpc/include/asm/checksum.h +++ b/arch/powerpc/include/asm/checksum.h @@ -164,7 +164,7 @@ static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl) */ __wsum __csum_partial(const void *buff, int len, __wsum sum); -static inline __wsum csum_partial(const void *buff, int len, __wsum sum) +static __always_inline __wsum csum_partial(const void *buff, int len, __wsum sum) { if (__builtin_constant_p(len) && len <= 16 && (len & 1) == 0) { if (len == 2)
ppc-linux-objdump -d vmlinux | grep -e "<csum_partial>" -e "<__csum_partial>" With gcc9 I get: c0017ef8 <__csum_partial>: c00182fc: 4b ff fb fd bl c0017ef8 <__csum_partial> c0018478: 4b ff fa 80 b c0017ef8 <__csum_partial> c03e8458: 4b c2 fa a0 b c0017ef8 <__csum_partial> c03e8518: 4b c2 f9 e1 bl c0017ef8 <__csum_partial> c03ef410: 4b c2 8a e9 bl c0017ef8 <__csum_partial> c03f0b24: 4b c2 73 d5 bl c0017ef8 <__csum_partial> c04279a4: 4b bf 05 55 bl c0017ef8 <__csum_partial> c0429820: 4b be e6 d9 bl c0017ef8 <__csum_partial> c0429944: 4b be e5 b5 bl c0017ef8 <__csum_partial> c042b478: 4b be ca 81 bl c0017ef8 <__csum_partial> c042b554: 4b be c9 a5 bl c0017ef8 <__csum_partial> c045f15c: 4b bb 8d 9d bl c0017ef8 <__csum_partial> c0492190: 4b b8 5d 69 bl c0017ef8 <__csum_partial> c0492310: 4b b8 5b e9 bl c0017ef8 <__csum_partial> c0495594: 4b b8 29 65 bl c0017ef8 <__csum_partial> c049c420: 4b b7 ba d9 bl c0017ef8 <__csum_partial> c049c870: 4b b7 b6 89 bl c0017ef8 <__csum_partial> c049c930: 4b b7 b5 c9 bl c0017ef8 <__csum_partial> c04a9ca0: 4b b6 e2 59 bl c0017ef8 <__csum_partial> c04bdde4: 4b b5 a1 15 bl c0017ef8 <__csum_partial> c04be480: 4b b5 9a 79 bl c0017ef8 <__csum_partial> c04be710: 4b b5 97 e9 bl c0017ef8 <__csum_partial> c04c969c: 4b b4 e8 5d bl c0017ef8 <__csum_partial> c04ca2fc: 4b b4 db fd bl c0017ef8 <__csum_partial> c04cf5bc: 4b b4 89 3d bl c0017ef8 <__csum_partial> c04d0440: 4b b4 7a b9 bl c0017ef8 <__csum_partial> With gcc10 I get: c0018d08 <__csum_partial>: c0019020 <csum_partial>: c0019020: 4b ff fc e8 b c0018d08 <__csum_partial> c001914c: 4b ff fe d4 b c0019020 <csum_partial> c0019250: 4b ff fd d1 bl c0019020 <csum_partial> c03e404c <csum_partial>: c03e404c: 4b c3 4c bc b c0018d08 <__csum_partial> c03e4050: 4b ff ff fc b c03e404c <csum_partial> c03e40fc: 4b ff ff 51 bl c03e404c <csum_partial> c03e6680: 4b ff d9 cd bl c03e404c <csum_partial> c03e68c4: 4b ff d7 89 bl c03e404c <csum_partial> c03e7934: 4b ff c7 19 bl c03e404c <csum_partial> c03e7bf8: 4b ff c4 55 bl c03e404c <csum_partial> c03eb148: 4b ff 8f 05 bl c03e404c <csum_partial> c03ecf68: 4b c2 bd a1 bl c0018d08 <__csum_partial> c04275b8 <csum_partial>: c04275b8: 4b bf 17 50 b c0018d08 <__csum_partial> c0427884: 4b ff fd 35 bl c04275b8 <csum_partial> c0427b18: 4b ff fa a1 bl c04275b8 <csum_partial> c0427bd8: 4b ff f9 e1 bl c04275b8 <csum_partial> c0427cd4: 4b ff f8 e5 bl c04275b8 <csum_partial> c0427e34: 4b ff f7 85 bl c04275b8 <csum_partial> c045a1c0: 4b bb eb 49 bl c0018d08 <__csum_partial> c0489464 <csum_partial>: c0489464: 4b b8 f8 a4 b c0018d08 <__csum_partial> c04896b0: 4b ff fd b5 bl c0489464 <csum_partial> c048982c: 4b ff fc 39 bl c0489464 <csum_partial> c0490158: 4b b8 8b b1 bl c0018d08 <__csum_partial> c0492f0c <csum_partial>: c0492f0c: 4b b8 5d fc b c0018d08 <__csum_partial> c049326c: 4b ff fc a1 bl c0492f0c <csum_partial> c049333c: 4b ff fb d1 bl c0492f0c <csum_partial> c0493b18: 4b ff f3 f5 bl c0492f0c <csum_partial> c0493f50: 4b ff ef bd bl c0492f0c <csum_partial> c0493ffc: 4b ff ef 11 bl c0492f0c <csum_partial> c04a0f78: 4b b7 7d 91 bl c0018d08 <__csum_partial> c04b3e3c: 4b b6 4e cd bl c0018d08 <__csum_partial> c04b40d0 <csum_partial>: c04b40d0: 4b b6 4c 38 b c0018d08 <__csum_partial> c04b4448: 4b ff fc 89 bl c04b40d0 <csum_partial> c04b46f4: 4b ff f9 dd bl c04b40d0 <csum_partial> c04bf448: 4b b5 98 c0 b c0018d08 <__csum_partial> c04c5264: 4b b5 3a a5 bl c0018d08 <__csum_partial> c04c61e4: 4b b5 2b 25 bl c0018d08 <__csum_partial> gcc10 defines multiple versions of csum_partial() which are just an unconditionnal branch to __csum_partial(). To enforce inlining of that branch to __csum_partial(), mark csum_partial() as __always_inline. With this patch with gcc10: c0018d08 <__csum_partial>: c0019148: 4b ff fb c0 b c0018d08 <__csum_partial> c001924c: 4b ff fa bd bl c0018d08 <__csum_partial> c03e40ec: 4b c3 4c 1d bl c0018d08 <__csum_partial> c03e4120: 4b c3 4b e8 b c0018d08 <__csum_partial> c03eb004: 4b c2 dd 05 bl c0018d08 <__csum_partial> c03ecef4: 4b c2 be 15 bl c0018d08 <__csum_partial> c0427558: 4b bf 17 b1 bl c0018d08 <__csum_partial> c04286e4: 4b bf 06 25 bl c0018d08 <__csum_partial> c0428cd8: 4b bf 00 31 bl c0018d08 <__csum_partial> c0428d84: 4b be ff 85 bl c0018d08 <__csum_partial> c045a17c: 4b bb eb 8d bl c0018d08 <__csum_partial> c0489450: 4b b8 f8 b9 bl c0018d08 <__csum_partial> c0491860: 4b b8 74 a9 bl c0018d08 <__csum_partial> c0492eec: 4b b8 5e 1d bl c0018d08 <__csum_partial> c04a0eac: 4b b7 7e 5d bl c0018d08 <__csum_partial> c04b3e34: 4b b6 4e d5 bl c0018d08 <__csum_partial> c04b426c: 4b b6 4a 9d bl c0018d08 <__csum_partial> c04b463c: 4b b6 46 cd bl c0018d08 <__csum_partial> c04c004c: 4b b5 8c bd bl c0018d08 <__csum_partial> c04c0368: 4b b5 89 a1 bl c0018d08 <__csum_partial> c04c5254: 4b b5 3a b5 bl c0018d08 <__csum_partial> c04c60d4: 4b b5 2c 35 bl c0018d08 <__csum_partial> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> --- arch/powerpc/include/asm/checksum.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)