| Message ID | 1536781219-13938-8-git-send-email-leitao@debian.org (mailing list archive) |
|---|---|
| State | RFC |
| Headers | show |
| Series | New TM Model | expand |
| Context | Check | Description |
|---|---|---|
| snowpatch_ozlabs/apply_patch | success | next/apply_patch Successfully applied |
| snowpatch_ozlabs/checkpatch | success | Test checkpatch on branch next |
On Wed, 2018-09-12 at 16:40 -0300, Breno Leitao wrote: > Do not recheckpoint at signal code return. Just make sure TIF_RESTORE_TM is > set, which will restore on the exit to userspace by restore_tm_state. Cool, but what about the same for reclaim? Why not avoid treclaim since it's done on entry? Mikey > > All the FP and VEC lazy restore was already done by tm_reclaim_current(), > where it checked if FP/VEC was set, and filled out the ckfp and ckvr > registers area to the expected value. > > The current FP/VEC restoration is not necessary, since the transaction will > be aborted and the checkpointed values will be restore. > > Signed-off-by: Breno Leitao <leitao@debian.org> > --- > arch/powerpc/kernel/signal_32.c | 23 +++-------------------- > arch/powerpc/kernel/signal_64.c | 15 ++------------- > 2 files changed, 5 insertions(+), 33 deletions(-) > > diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c > index e6474a45cef5..4a1b17409bf3 100644 > --- a/arch/powerpc/kernel/signal_32.c > +++ b/arch/powerpc/kernel/signal_32.c > @@ -850,28 +850,11 @@ static long restore_tm_user_regs(struct pt_regs *regs, > return 1; > /* Pull in the MSR TM bits from the user context */ > regs->msr = (regs->msr & ~MSR_TS_MASK) | (msr_hi & MSR_TS_MASK); > - /* Now, recheckpoint. This loads up all of the checkpointed (older) > - * registers, including FP and V[S]Rs. After recheckpointing, the > - * transactional versions should be loaded. > - */ > - tm_enable(); > + > /* Make sure the transaction is marked as failed */ > current->thread.tm_texasr |= TEXASR_FS; > - /* This loads the checkpointed FP/VEC state, if used */ > - tm_recheckpoint(¤t->thread); > - > - /* This loads the speculative FP/VEC state, if used */ > - msr_check_and_set(msr & (MSR_FP | MSR_VEC)); > - if (msr & MSR_FP) { > - load_fp_state(¤t->thread.fp_state); > - regs->msr |= (MSR_FP | current->thread.fpexc_mode); > - } > -#ifdef CONFIG_ALTIVEC > - if (msr & MSR_VEC) { > - load_vr_state(¤t->thread.vr_state); > - regs->msr |= MSR_VEC; > - } > -#endif > + /* Make sure restore_tm_state will be called */ > + set_thread_flag(TIF_RESTORE_TM); > > return 0; > } > diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c > index 83d51bf586c7..32402aa23a5e 100644 > --- a/arch/powerpc/kernel/signal_64.c > +++ b/arch/powerpc/kernel/signal_64.c > @@ -569,21 +569,10 @@ static long restore_tm_sigcontexts(struct task_struct > *tsk, > } > } > #endif > - tm_enable(); > /* Make sure the transaction is marked as failed */ > tsk->thread.tm_texasr |= TEXASR_FS; > - /* This loads the checkpointed FP/VEC state, if used */ > - tm_recheckpoint(&tsk->thread); > - > - msr_check_and_set(msr & (MSR_FP | MSR_VEC)); > - if (msr & MSR_FP) { > - load_fp_state(&tsk->thread.fp_state); > - regs->msr |= (MSR_FP | tsk->thread.fpexc_mode); > - } > - if (msr & MSR_VEC) { > - load_vr_state(&tsk->thread.vr_state); > - regs->msr |= MSR_VEC; > - } > + /* Guarantee that restore_tm_state() will be called */ > + set_thread_flag(TIF_RESTORE_TM); > > return err; > }
diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c index e6474a45cef5..4a1b17409bf3 100644 --- a/arch/powerpc/kernel/signal_32.c +++ b/arch/powerpc/kernel/signal_32.c @@ -850,28 +850,11 @@ static long restore_tm_user_regs(struct pt_regs *regs, return 1; /* Pull in the MSR TM bits from the user context */ regs->msr = (regs->msr & ~MSR_TS_MASK) | (msr_hi & MSR_TS_MASK); - /* Now, recheckpoint. This loads up all of the checkpointed (older) - * registers, including FP and V[S]Rs. After recheckpointing, the - * transactional versions should be loaded. - */ - tm_enable(); + /* Make sure the transaction is marked as failed */ current->thread.tm_texasr |= TEXASR_FS; - /* This loads the checkpointed FP/VEC state, if used */ - tm_recheckpoint(¤t->thread); - - /* This loads the speculative FP/VEC state, if used */ - msr_check_and_set(msr & (MSR_FP | MSR_VEC)); - if (msr & MSR_FP) { - load_fp_state(¤t->thread.fp_state); - regs->msr |= (MSR_FP | current->thread.fpexc_mode); - } -#ifdef CONFIG_ALTIVEC - if (msr & MSR_VEC) { - load_vr_state(¤t->thread.vr_state); - regs->msr |= MSR_VEC; - } -#endif + /* Make sure restore_tm_state will be called */ + set_thread_flag(TIF_RESTORE_TM); return 0; } diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c index 83d51bf586c7..32402aa23a5e 100644 --- a/arch/powerpc/kernel/signal_64.c +++ b/arch/powerpc/kernel/signal_64.c @@ -569,21 +569,10 @@ static long restore_tm_sigcontexts(struct task_struct *tsk, } } #endif - tm_enable(); /* Make sure the transaction is marked as failed */ tsk->thread.tm_texasr |= TEXASR_FS; - /* This loads the checkpointed FP/VEC state, if used */ - tm_recheckpoint(&tsk->thread); - - msr_check_and_set(msr & (MSR_FP | MSR_VEC)); - if (msr & MSR_FP) { - load_fp_state(&tsk->thread.fp_state); - regs->msr |= (MSR_FP | tsk->thread.fpexc_mode); - } - if (msr & MSR_VEC) { - load_vr_state(&tsk->thread.vr_state); - regs->msr |= MSR_VEC; - } + /* Guarantee that restore_tm_state() will be called */ + set_thread_flag(TIF_RESTORE_TM); return err; }
Do not recheckpoint at signal code return. Just make sure TIF_RESTORE_TM is set, which will restore on the exit to userspace by restore_tm_state. All the FP and VEC lazy restore was already done by tm_reclaim_current(), where it checked if FP/VEC was set, and filled out the ckfp and ckvr registers area to the expected value. The current FP/VEC restoration is not necessary, since the transaction will be aborted and the checkpointed values will be restore. Signed-off-by: Breno Leitao <leitao@debian.org> --- arch/powerpc/kernel/signal_32.c | 23 +++-------------------- arch/powerpc/kernel/signal_64.c | 15 ++------------- 2 files changed, 5 insertions(+), 33 deletions(-)