Message ID | 1429721610-8251-1-git-send-email-cota@braap.org |
---|---|
State | New |
Headers | show |
On 22/04/2015 18:53, Emilio G. Cota wrote: > Here we have an open-coded byte-based bitmap implementation. > Get rid of it since there's a ulong-based implementation to be > used by all code. > > Signed-off-by: Emilio G. Cota <cota@braap.org> > --- > translate-all.c | 40 +++++++--------------------------------- > 1 file changed, 7 insertions(+), 33 deletions(-) > > diff --git a/translate-all.c b/translate-all.c > index acf792c..9592a3b 100644 > --- a/translate-all.c > +++ b/translate-all.c > @@ -59,6 +59,7 @@ > > #include "exec/cputlb.h" > #include "translate-all.h" > +#include "qemu/bitmap.h" > #include "qemu/timer.h" > > //#define DEBUG_TB_INVALIDATE > @@ -79,7 +80,7 @@ typedef struct PageDesc { > /* in order to optimize self modifying code, we count the number > of lookups we do to a given page to use a bitmap */ > unsigned int code_write_count; > - uint8_t *code_bitmap; > + unsigned long *code_bitmap; > #if defined(CONFIG_USER_ONLY) > unsigned long flags; > #endif > @@ -964,39 +965,12 @@ void tb_phys_invalidate(TranslationBlock *tb, tb_page_addr_t page_addr) > tcg_ctx.tb_ctx.tb_phys_invalidate_count++; > } > > -static inline void set_bits(uint8_t *tab, int start, int len) > -{ > - int end, mask, end1; > - > - end = start + len; > - tab += start >> 3; > - mask = 0xff << (start & 7); > - if ((start & ~7) == (end & ~7)) { > - if (start < end) { > - mask &= ~(0xff << (end & 7)); > - *tab |= mask; > - } > - } else { > - *tab++ |= mask; > - start = (start + 8) & ~7; > - end1 = end & ~7; > - while (start < end1) { > - *tab++ = 0xff; > - start += 8; > - } > - if (start < end) { > - mask = ~(0xff << (end & 7)); > - *tab |= mask; > - } > - } > -} > - > static void build_page_bitmap(PageDesc *p) > { > int n, tb_start, tb_end; > TranslationBlock *tb; > > - p->code_bitmap = g_malloc0(TARGET_PAGE_SIZE / 8); > + p->code_bitmap = bitmap_new(TARGET_PAGE_SIZE); > > tb = p->first_tb; > while (tb != NULL) { > @@ -1015,7 +989,7 @@ static void build_page_bitmap(PageDesc *p) > tb_start = 0; > tb_end = ((tb->pc + tb->size) & ~TARGET_PAGE_MASK); > } > - set_bits(p->code_bitmap, tb_start, tb_end - tb_start); > + bitmap_set(p->code_bitmap, tb_start, tb_end - tb_start); > tb = tb->page_next[n]; > } > } > @@ -1205,7 +1179,6 @@ void tb_invalidate_phys_page_range(tb_page_addr_t start, tb_page_addr_t end, > void tb_invalidate_phys_page_fast(tb_page_addr_t start, int len) > { > PageDesc *p; > - int offset, b; > > #if 0 > if (1) { > @@ -1221,8 +1194,9 @@ void tb_invalidate_phys_page_fast(tb_page_addr_t start, int len) > return; > } > if (p->code_bitmap) { > - offset = start & ~TARGET_PAGE_MASK; > - b = p->code_bitmap[offset >> 3] >> (offset & 7); > + int nr = start & ~TARGET_PAGE_MASK; This should be unsigned, otherwise the compiler might not make BIT_WORD(nr) a simple right shift (maybe it can see that nr > 0 thanks to the AND, but in principle x / 32 is not the same as x >> 5 if x is signed). > + int b = p->code_bitmap[BIT_WORD(nr)] >> (nr & (BITS_PER_LONG - 1)); And this should be unsigned long. Otherwise looks good. Paolo > + > if (b & ((1 << len) - 1)) { > goto do_invalidate; > } >
On Wed, Apr 22, 2015 at 22:30:23 +0200, Paolo Bonzini wrote: > On 22/04/2015 18:53, Emilio G. Cota wrote: > > @@ -1221,8 +1194,9 @@ void tb_invalidate_phys_page_fast(tb_page_addr_t start, int len) > > return; > > } > > if (p->code_bitmap) { > > - offset = start & ~TARGET_PAGE_MASK; > > - b = p->code_bitmap[offset >> 3] >> (offset & 7); > > + int nr = start & ~TARGET_PAGE_MASK; > > This should be unsigned, otherwise the compiler might not make > BIT_WORD(nr) a simple right shift (maybe it can see that nr > 0 thanks > to the AND, but in principle x / 32 is not the same as x >> 5 if x is > signed). OK. Note that all bit{map,ops} helpers take a long as the bit position, and then do BIT_WORD() on it--I was following that convention wrt sign. > > + int b = p->code_bitmap[BIT_WORD(nr)] >> (nr & (BITS_PER_LONG - 1)); > > And this should be unsigned long. Used an int because we only care about the least significant bits (len <= 8): > > if (b & ((1 << len) - 1)) { > > goto do_invalidate; > > } But yes, an unsigned long here is more appropriate. Thanks, Emilio
diff --git a/translate-all.c b/translate-all.c index acf792c..9592a3b 100644 --- a/translate-all.c +++ b/translate-all.c @@ -59,6 +59,7 @@ #include "exec/cputlb.h" #include "translate-all.h" +#include "qemu/bitmap.h" #include "qemu/timer.h" //#define DEBUG_TB_INVALIDATE @@ -79,7 +80,7 @@ typedef struct PageDesc { /* in order to optimize self modifying code, we count the number of lookups we do to a given page to use a bitmap */ unsigned int code_write_count; - uint8_t *code_bitmap; + unsigned long *code_bitmap; #if defined(CONFIG_USER_ONLY) unsigned long flags; #endif @@ -964,39 +965,12 @@ void tb_phys_invalidate(TranslationBlock *tb, tb_page_addr_t page_addr) tcg_ctx.tb_ctx.tb_phys_invalidate_count++; } -static inline void set_bits(uint8_t *tab, int start, int len) -{ - int end, mask, end1; - - end = start + len; - tab += start >> 3; - mask = 0xff << (start & 7); - if ((start & ~7) == (end & ~7)) { - if (start < end) { - mask &= ~(0xff << (end & 7)); - *tab |= mask; - } - } else { - *tab++ |= mask; - start = (start + 8) & ~7; - end1 = end & ~7; - while (start < end1) { - *tab++ = 0xff; - start += 8; - } - if (start < end) { - mask = ~(0xff << (end & 7)); - *tab |= mask; - } - } -} - static void build_page_bitmap(PageDesc *p) { int n, tb_start, tb_end; TranslationBlock *tb; - p->code_bitmap = g_malloc0(TARGET_PAGE_SIZE / 8); + p->code_bitmap = bitmap_new(TARGET_PAGE_SIZE); tb = p->first_tb; while (tb != NULL) { @@ -1015,7 +989,7 @@ static void build_page_bitmap(PageDesc *p) tb_start = 0; tb_end = ((tb->pc + tb->size) & ~TARGET_PAGE_MASK); } - set_bits(p->code_bitmap, tb_start, tb_end - tb_start); + bitmap_set(p->code_bitmap, tb_start, tb_end - tb_start); tb = tb->page_next[n]; } } @@ -1205,7 +1179,6 @@ void tb_invalidate_phys_page_range(tb_page_addr_t start, tb_page_addr_t end, void tb_invalidate_phys_page_fast(tb_page_addr_t start, int len) { PageDesc *p; - int offset, b; #if 0 if (1) { @@ -1221,8 +1194,9 @@ void tb_invalidate_phys_page_fast(tb_page_addr_t start, int len) return; } if (p->code_bitmap) { - offset = start & ~TARGET_PAGE_MASK; - b = p->code_bitmap[offset >> 3] >> (offset & 7); + int nr = start & ~TARGET_PAGE_MASK; + int b = p->code_bitmap[BIT_WORD(nr)] >> (nr & (BITS_PER_LONG - 1)); + if (b & ((1 << len) - 1)) { goto do_invalidate; }
Here we have an open-coded byte-based bitmap implementation. Get rid of it since there's a ulong-based implementation to be used by all code. Signed-off-by: Emilio G. Cota <cota@braap.org> --- translate-all.c | 40 +++++++--------------------------------- 1 file changed, 7 insertions(+), 33 deletions(-)