| Message ID | 20190718010456.4234-2-richardw.yang@linux.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | bitmap: refine bitmap_set | expand |
On Thu, Jul 18, 2019 at 09:04:55AM +0800, Wei Yang wrote: >The value left in nr is the number of bits for the last word, which >could be calculate the last word mask directly. > >Remove the unnecessary size. > May I ask why Patch 2 is picked up, but this one is not? >Signed-off-by: Wei Yang <richardw.yang@linux.intel.com> > >--- >v2: refine bitmap_set_atomic too, suggested from Peter >--- > util/bitmap.c | 9 +++------ > 1 file changed, 3 insertions(+), 6 deletions(-) > >diff --git a/util/bitmap.c b/util/bitmap.c >index 1753ff7f5b..5b15249796 100644 >--- a/util/bitmap.c >+++ b/util/bitmap.c >@@ -160,7 +160,6 @@ int slow_bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, > void bitmap_set(unsigned long *map, long start, long nr) > { > unsigned long *p = map + BIT_WORD(start); >- const long size = start + nr; > int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG); > unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start); > >@@ -174,7 +173,7 @@ void bitmap_set(unsigned long *map, long start, long nr) > p++; > } > if (nr) { >- mask_to_set &= BITMAP_LAST_WORD_MASK(size); >+ mask_to_set &= BITMAP_LAST_WORD_MASK(nr); > *p |= mask_to_set; > } > } >@@ -182,7 +181,6 @@ void bitmap_set(unsigned long *map, long start, long nr) > void bitmap_set_atomic(unsigned long *map, long start, long nr) > { > unsigned long *p = map + BIT_WORD(start); >- const long size = start + nr; > int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG); > unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start); > >@@ -208,7 +206,7 @@ void bitmap_set_atomic(unsigned long *map, long start, long nr) > > /* Last word */ > if (nr) { >- mask_to_set &= BITMAP_LAST_WORD_MASK(size); >+ mask_to_set &= BITMAP_LAST_WORD_MASK(nr); > atomic_or(p, mask_to_set); > } else { > /* If we avoided the full barrier in atomic_or(), issue a >@@ -221,7 +219,6 @@ void bitmap_set_atomic(unsigned long *map, long start, long nr) > void bitmap_clear(unsigned long *map, long start, long nr) > { > unsigned long *p = map + BIT_WORD(start); >- const long size = start + nr; > int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG); > unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start); > >@@ -235,7 +232,7 @@ void bitmap_clear(unsigned long *map, long start, long nr) > p++; > } > if (nr) { >- mask_to_clear &= BITMAP_LAST_WORD_MASK(size); >+ mask_to_clear &= BITMAP_LAST_WORD_MASK(nr); > *p &= ~mask_to_clear; > } > } >-- >2.17.1 >
On 21/07/19 02:33, Wei Yang wrote: > On Thu, Jul 18, 2019 at 09:04:55AM +0800, Wei Yang wrote: >> The value left in nr is the number of bits for the last word, which >> could be calculate the last word mask directly. >> >> Remove the unnecessary size. >> > > May I ask why Patch 2 is picked up, but this one is not? Tests are always good to have, this cleanup will wait for 4.2 but it's in the queue. Paolo >> Signed-off-by: Wei Yang <richardw.yang@linux.intel.com> >> >> --- >> v2: refine bitmap_set_atomic too, suggested from Peter >> --- >> util/bitmap.c | 9 +++------ >> 1 file changed, 3 insertions(+), 6 deletions(-) >> >> diff --git a/util/bitmap.c b/util/bitmap.c >> index 1753ff7f5b..5b15249796 100644 >> --- a/util/bitmap.c >> +++ b/util/bitmap.c >> @@ -160,7 +160,6 @@ int slow_bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, >> void bitmap_set(unsigned long *map, long start, long nr) >> { >> unsigned long *p = map + BIT_WORD(start); >> - const long size = start + nr; >> int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG); >> unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start); >> >> @@ -174,7 +173,7 @@ void bitmap_set(unsigned long *map, long start, long nr) >> p++; >> } >> if (nr) { >> - mask_to_set &= BITMAP_LAST_WORD_MASK(size); >> + mask_to_set &= BITMAP_LAST_WORD_MASK(nr); >> *p |= mask_to_set; >> } >> } >> @@ -182,7 +181,6 @@ void bitmap_set(unsigned long *map, long start, long nr) >> void bitmap_set_atomic(unsigned long *map, long start, long nr) >> { >> unsigned long *p = map + BIT_WORD(start); >> - const long size = start + nr; >> int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG); >> unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start); >> >> @@ -208,7 +206,7 @@ void bitmap_set_atomic(unsigned long *map, long start, long nr) >> >> /* Last word */ >> if (nr) { >> - mask_to_set &= BITMAP_LAST_WORD_MASK(size); >> + mask_to_set &= BITMAP_LAST_WORD_MASK(nr); >> atomic_or(p, mask_to_set); >> } else { >> /* If we avoided the full barrier in atomic_or(), issue a >> @@ -221,7 +219,6 @@ void bitmap_set_atomic(unsigned long *map, long start, long nr) >> void bitmap_clear(unsigned long *map, long start, long nr) >> { >> unsigned long *p = map + BIT_WORD(start); >> - const long size = start + nr; >> int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG); >> unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start); >> >> @@ -235,7 +232,7 @@ void bitmap_clear(unsigned long *map, long start, long nr) >> p++; >> } >> if (nr) { >> - mask_to_clear &= BITMAP_LAST_WORD_MASK(size); >> + mask_to_clear &= BITMAP_LAST_WORD_MASK(nr); >> *p &= ~mask_to_clear; >> } >> } >> -- >> 2.17.1 >> >
On Sun, Jul 21, 2019 at 07:27:14PM +0200, Paolo Bonzini wrote: >On 21/07/19 02:33, Wei Yang wrote: >> On Thu, Jul 18, 2019 at 09:04:55AM +0800, Wei Yang wrote: >>> The value left in nr is the number of bits for the last word, which >>> could be calculate the last word mask directly. >>> >>> Remove the unnecessary size. >>> >> >> May I ask why Patch 2 is picked up, but this one is not? > >Tests are always good to have, this cleanup will wait for 4.2 but it's >in the queue. > Thanks :-) >Paolo > >>> Signed-off-by: Wei Yang <richardw.yang@linux.intel.com> >>> >>> --- >>> v2: refine bitmap_set_atomic too, suggested from Peter >>> --- >>> util/bitmap.c | 9 +++------ >>> 1 file changed, 3 insertions(+), 6 deletions(-) >>> >>> diff --git a/util/bitmap.c b/util/bitmap.c >>> index 1753ff7f5b..5b15249796 100644 >>> --- a/util/bitmap.c >>> +++ b/util/bitmap.c >>> @@ -160,7 +160,6 @@ int slow_bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, >>> void bitmap_set(unsigned long *map, long start, long nr) >>> { >>> unsigned long *p = map + BIT_WORD(start); >>> - const long size = start + nr; >>> int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG); >>> unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start); >>> >>> @@ -174,7 +173,7 @@ void bitmap_set(unsigned long *map, long start, long nr) >>> p++; >>> } >>> if (nr) { >>> - mask_to_set &= BITMAP_LAST_WORD_MASK(size); >>> + mask_to_set &= BITMAP_LAST_WORD_MASK(nr); >>> *p |= mask_to_set; >>> } >>> } >>> @@ -182,7 +181,6 @@ void bitmap_set(unsigned long *map, long start, long nr) >>> void bitmap_set_atomic(unsigned long *map, long start, long nr) >>> { >>> unsigned long *p = map + BIT_WORD(start); >>> - const long size = start + nr; >>> int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG); >>> unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start); >>> >>> @@ -208,7 +206,7 @@ void bitmap_set_atomic(unsigned long *map, long start, long nr) >>> >>> /* Last word */ >>> if (nr) { >>> - mask_to_set &= BITMAP_LAST_WORD_MASK(size); >>> + mask_to_set &= BITMAP_LAST_WORD_MASK(nr); >>> atomic_or(p, mask_to_set); >>> } else { >>> /* If we avoided the full barrier in atomic_or(), issue a >>> @@ -221,7 +219,6 @@ void bitmap_set_atomic(unsigned long *map, long start, long nr) >>> void bitmap_clear(unsigned long *map, long start, long nr) >>> { >>> unsigned long *p = map + BIT_WORD(start); >>> - const long size = start + nr; >>> int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG); >>> unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start); >>> >>> @@ -235,7 +232,7 @@ void bitmap_clear(unsigned long *map, long start, long nr) >>> p++; >>> } >>> if (nr) { >>> - mask_to_clear &= BITMAP_LAST_WORD_MASK(size); >>> + mask_to_clear &= BITMAP_LAST_WORD_MASK(nr); >>> *p &= ~mask_to_clear; >>> } >>> } >>> -- >>> 2.17.1 >>> >>
On 18/07/19 03:04, Wei Yang wrote: > The value left in nr is the number of bits for the last word, which > could be calculate the last word mask directly. > > Remove the unnecessary size. Hi, the value left in nr is _not_ the number of bits for the last word if the start and the end are in the same word. For example, if start % BITS_PER_LONG was 3 and nr == 1, you'd have: - before the patch BITMAP_LAST_WORD_MASK(4) - after the patch BITMAP_LAST_WORD_MASK(1) Paolo > Signed-off-by: Wei Yang <richardw.yang@linux.intel.com> > > --- > v2: refine bitmap_set_atomic too, suggested from Peter > --- > util/bitmap.c | 9 +++------ > 1 file changed, 3 insertions(+), 6 deletions(-) > > diff --git a/util/bitmap.c b/util/bitmap.c > index 1753ff7f5b..5b15249796 100644 > --- a/util/bitmap.c > +++ b/util/bitmap.c > @@ -160,7 +160,6 @@ int slow_bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, > void bitmap_set(unsigned long *map, long start, long nr) > { > unsigned long *p = map + BIT_WORD(start); > - const long size = start + nr; > int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG); > unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start); > > @@ -174,7 +173,7 @@ void bitmap_set(unsigned long *map, long start, long nr) > p++; > } > if (nr) { > - mask_to_set &= BITMAP_LAST_WORD_MASK(size); > + mask_to_set &= BITMAP_LAST_WORD_MASK(nr); > *p |= mask_to_set; > } > } > @@ -182,7 +181,6 @@ void bitmap_set(unsigned long *map, long start, long nr) > void bitmap_set_atomic(unsigned long *map, long start, long nr) > { > unsigned long *p = map + BIT_WORD(start); > - const long size = start + nr; > int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG); > unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start); > > @@ -208,7 +206,7 @@ void bitmap_set_atomic(unsigned long *map, long start, long nr) > > /* Last word */ > if (nr) { > - mask_to_set &= BITMAP_LAST_WORD_MASK(size); > + mask_to_set &= BITMAP_LAST_WORD_MASK(nr); > atomic_or(p, mask_to_set); > } else { > /* If we avoided the full barrier in atomic_or(), issue a > @@ -221,7 +219,6 @@ void bitmap_set_atomic(unsigned long *map, long start, long nr) > void bitmap_clear(unsigned long *map, long start, long nr) > { > unsigned long *p = map + BIT_WORD(start); > - const long size = start + nr; > int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG); > unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start); > > @@ -235,7 +232,7 @@ void bitmap_clear(unsigned long *map, long start, long nr) > p++; > } > if (nr) { > - mask_to_clear &= BITMAP_LAST_WORD_MASK(size); > + mask_to_clear &= BITMAP_LAST_WORD_MASK(nr); > *p &= ~mask_to_clear; > } > } >
On Mon, Aug 12, 2019 at 06:18:43PM +0200, Paolo Bonzini wrote: >On 18/07/19 03:04, Wei Yang wrote: >> The value left in nr is the number of bits for the last word, which >> could be calculate the last word mask directly. >> >> Remove the unnecessary size. > >Hi, > >the value left in nr is _not_ the number of bits for the last word if >the start and the end are in the same word. For example, if start % >BITS_PER_LONG was 3 and nr == 1, you'd have: > >- before the patch BITMAP_LAST_WORD_MASK(4) > >- after the patch BITMAP_LAST_WORD_MASK(1) > You are right. I missed this case. Thanks for pointing out. >Paolo > >> Signed-off-by: Wei Yang <richardw.yang@linux.intel.com> >> >> --- >> v2: refine bitmap_set_atomic too, suggested from Peter >> --- >> util/bitmap.c | 9 +++------ >> 1 file changed, 3 insertions(+), 6 deletions(-) >> >> diff --git a/util/bitmap.c b/util/bitmap.c >> index 1753ff7f5b..5b15249796 100644 >> --- a/util/bitmap.c >> +++ b/util/bitmap.c >> @@ -160,7 +160,6 @@ int slow_bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, >> void bitmap_set(unsigned long *map, long start, long nr) >> { >> unsigned long *p = map + BIT_WORD(start); >> - const long size = start + nr; >> int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG); >> unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start); >> >> @@ -174,7 +173,7 @@ void bitmap_set(unsigned long *map, long start, long nr) >> p++; >> } >> if (nr) { >> - mask_to_set &= BITMAP_LAST_WORD_MASK(size); >> + mask_to_set &= BITMAP_LAST_WORD_MASK(nr); >> *p |= mask_to_set; >> } >> } >> @@ -182,7 +181,6 @@ void bitmap_set(unsigned long *map, long start, long nr) >> void bitmap_set_atomic(unsigned long *map, long start, long nr) >> { >> unsigned long *p = map + BIT_WORD(start); >> - const long size = start + nr; >> int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG); >> unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start); >> >> @@ -208,7 +206,7 @@ void bitmap_set_atomic(unsigned long *map, long start, long nr) >> >> /* Last word */ >> if (nr) { >> - mask_to_set &= BITMAP_LAST_WORD_MASK(size); >> + mask_to_set &= BITMAP_LAST_WORD_MASK(nr); >> atomic_or(p, mask_to_set); >> } else { >> /* If we avoided the full barrier in atomic_or(), issue a >> @@ -221,7 +219,6 @@ void bitmap_set_atomic(unsigned long *map, long start, long nr) >> void bitmap_clear(unsigned long *map, long start, long nr) >> { >> unsigned long *p = map + BIT_WORD(start); >> - const long size = start + nr; >> int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG); >> unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start); >> >> @@ -235,7 +232,7 @@ void bitmap_clear(unsigned long *map, long start, long nr) >> p++; >> } >> if (nr) { >> - mask_to_clear &= BITMAP_LAST_WORD_MASK(size); >> + mask_to_clear &= BITMAP_LAST_WORD_MASK(nr); >> *p &= ~mask_to_clear; >> } >> } >> >
diff --git a/util/bitmap.c b/util/bitmap.c index 1753ff7f5b..5b15249796 100644 --- a/util/bitmap.c +++ b/util/bitmap.c @@ -160,7 +160,6 @@ int slow_bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, void bitmap_set(unsigned long *map, long start, long nr) { unsigned long *p = map + BIT_WORD(start); - const long size = start + nr; int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG); unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start); @@ -174,7 +173,7 @@ void bitmap_set(unsigned long *map, long start, long nr) p++; } if (nr) { - mask_to_set &= BITMAP_LAST_WORD_MASK(size); + mask_to_set &= BITMAP_LAST_WORD_MASK(nr); *p |= mask_to_set; } } @@ -182,7 +181,6 @@ void bitmap_set(unsigned long *map, long start, long nr) void bitmap_set_atomic(unsigned long *map, long start, long nr) { unsigned long *p = map + BIT_WORD(start); - const long size = start + nr; int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG); unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start); @@ -208,7 +206,7 @@ void bitmap_set_atomic(unsigned long *map, long start, long nr) /* Last word */ if (nr) { - mask_to_set &= BITMAP_LAST_WORD_MASK(size); + mask_to_set &= BITMAP_LAST_WORD_MASK(nr); atomic_or(p, mask_to_set); } else { /* If we avoided the full barrier in atomic_or(), issue a @@ -221,7 +219,6 @@ void bitmap_set_atomic(unsigned long *map, long start, long nr) void bitmap_clear(unsigned long *map, long start, long nr) { unsigned long *p = map + BIT_WORD(start); - const long size = start + nr; int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG); unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start); @@ -235,7 +232,7 @@ void bitmap_clear(unsigned long *map, long start, long nr) p++; } if (nr) { - mask_to_clear &= BITMAP_LAST_WORD_MASK(size); + mask_to_clear &= BITMAP_LAST_WORD_MASK(nr); *p &= ~mask_to_clear; } }
The value left in nr is the number of bits for the last word, which could be calculate the last word mask directly. Remove the unnecessary size. Signed-off-by: Wei Yang <richardw.yang@linux.intel.com> --- v2: refine bitmap_set_atomic too, suggested from Peter --- util/bitmap.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-)