| Message ID | 1467735496-16256-3-git-send-email-alex.bennee@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 05/07/16 19:18, Alex Bennée wrote: > This ensures that if we find the TB on the slow path that tb->page_addr > is correctly set before being tested. > > Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Reveiwed-by: Sergey Fedorov <sergey.fedorov@linaro.org> > --- > translate-all.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/translate-all.c b/translate-all.c > index 96efe48..97e834a 100644 > --- a/translate-all.c > +++ b/translate-all.c > @@ -1126,10 +1126,6 @@ static void tb_link_page(TranslationBlock *tb, tb_page_addr_t phys_pc, > { > uint32_t h; > > - /* add in the hash table */ > - h = tb_hash_func(phys_pc, tb->pc, tb->flags); > - qht_insert(&tcg_ctx.tb_ctx.htable, tb, h); > - > /* add in the page list */ > tb_alloc_page(tb, 0, phys_pc & TARGET_PAGE_MASK); > if (phys_page2 != -1) { > @@ -1138,6 +1134,10 @@ static void tb_link_page(TranslationBlock *tb, tb_page_addr_t phys_pc, > tb->page_addr[1] = -1; > } > > + /* add in the hash table */ > + h = tb_hash_func(phys_pc, tb->pc, tb->flags); > + qht_insert(&tcg_ctx.tb_ctx.htable, tb, h); > + > #ifdef DEBUG_TB_CHECK > tb_page_check(); > #endif
On 07/07/16 17:08, Sergey Fedorov wrote: > On 05/07/16 19:18, Alex Bennée wrote: >> This ensures that if we find the TB on the slow path that tb->page_addr >> is correctly set before being tested. >> >> Signed-off-by: Alex Bennée <alex.bennee@linaro.org> > Reveiwed-by: Sergey Fedorov <sergey.fedorov@linaro.org> However, we may need to use smp_wmb() here paired with smp_rmb() in tb_find_fast(). Alternatively, QHT might provide some explicit guarantee about memory ordering around qht_insert() and qht_lookup(). Actually, there is already right ordering thanks to seqlock operations in QHT implementation. This means we could elide explicit memory barrier from the first patch as well. Kind regards, Sergey > >> --- >> translate-all.c | 8 ++++---- >> 1 file changed, 4 insertions(+), 4 deletions(-) >> >> diff --git a/translate-all.c b/translate-all.c >> index 96efe48..97e834a 100644 >> --- a/translate-all.c >> +++ b/translate-all.c >> @@ -1126,10 +1126,6 @@ static void tb_link_page(TranslationBlock *tb, tb_page_addr_t phys_pc, >> { >> uint32_t h; >> >> - /* add in the hash table */ >> - h = tb_hash_func(phys_pc, tb->pc, tb->flags); >> - qht_insert(&tcg_ctx.tb_ctx.htable, tb, h); >> - >> /* add in the page list */ >> tb_alloc_page(tb, 0, phys_pc & TARGET_PAGE_MASK); >> if (phys_page2 != -1) { >> @@ -1138,6 +1134,10 @@ static void tb_link_page(TranslationBlock *tb, tb_page_addr_t phys_pc, >> tb->page_addr[1] = -1; >> } >> >> + /* add in the hash table */ >> + h = tb_hash_func(phys_pc, tb->pc, tb->flags); >> + qht_insert(&tcg_ctx.tb_ctx.htable, tb, h); >> + >> #ifdef DEBUG_TB_CHECK >> tb_page_check(); >> #endif
diff --git a/translate-all.c b/translate-all.c index 96efe48..97e834a 100644 --- a/translate-all.c +++ b/translate-all.c @@ -1126,10 +1126,6 @@ static void tb_link_page(TranslationBlock *tb, tb_page_addr_t phys_pc, { uint32_t h; - /* add in the hash table */ - h = tb_hash_func(phys_pc, tb->pc, tb->flags); - qht_insert(&tcg_ctx.tb_ctx.htable, tb, h); - /* add in the page list */ tb_alloc_page(tb, 0, phys_pc & TARGET_PAGE_MASK); if (phys_page2 != -1) { @@ -1138,6 +1134,10 @@ static void tb_link_page(TranslationBlock *tb, tb_page_addr_t phys_pc, tb->page_addr[1] = -1; } + /* add in the hash table */ + h = tb_hash_func(phys_pc, tb->pc, tb->flags); + qht_insert(&tcg_ctx.tb_ctx.htable, tb, h); + #ifdef DEBUG_TB_CHECK tb_page_check(); #endif
This ensures that if we find the TB on the slow path that tb->page_addr is correctly set before being tested. Signed-off-by: Alex Bennée <alex.bennee@linaro.org> --- translate-all.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)