4.19-stable patches

added patches:
	bitmap-introduce-generic-optimized-bitmap_size.patch

diff --git a/queue-4.19/bitmap-introduce-generic-optimized-bitmap_size.patch b/queue-4.19/bitmap-introduce-generic-optimized-bitmap_size.patch
new file mode 100644 (file)
index 0000000..94e2196
--- /dev/null
+++ b/queue-4.19/bitmap-introduce-generic-optimized-bitmap_size.patch
@@ -0,0 +1,145 @@
+From a37fbe666c016fd89e4460d0ebfcea05baba46dc Mon Sep 17 00:00:00 2001
+From: Alexander Lobakin <aleksander.lobakin@intel.com>
+Date: Wed, 27 Mar 2024 16:23:49 +0100
+Subject: bitmap: introduce generic optimized bitmap_size()
+
+From: Alexander Lobakin <aleksander.lobakin@intel.com>
+
+commit a37fbe666c016fd89e4460d0ebfcea05baba46dc upstream.
+
+The number of times yet another open coded
+`BITS_TO_LONGS(nbits) * sizeof(long)` can be spotted is huge.
+Some generic helper is long overdue.
+
+Add one, bitmap_size(), but with one detail.
+BITS_TO_LONGS() uses DIV_ROUND_UP(). The latter works well when both
+divident and divisor are compile-time constants or when the divisor
+is not a pow-of-2. When it is however, the compilers sometimes tend
+to generate suboptimal code (GCC 13):
+
+48 83 c0 3f            add    $0x3f,%rax
+48 c1 e8 06            shr    $0x6,%rax
+48 8d 14 c5 00 00 00 00        lea    0x0(,%rax,8),%rdx
+
+%BITS_PER_LONG is always a pow-2 (either 32 or 64), but GCC still does
+full division of `nbits + 63` by it and then multiplication by 8.
+Instead of BITS_TO_LONGS(), use ALIGN() and then divide by 8. GCC:
+
+8d 50 3f               lea    0x3f(%rax),%edx
+c1 ea 03               shr    $0x3,%edx
+81 e2 f8 ff ff 1f      and    $0x1ffffff8,%edx
+
+Now it shifts `nbits + 63` by 3 positions (IOW performs fast division
+by 8) and then masks bits[2:0]. bloat-o-meter:
+
+add/remove: 0/0 grow/shrink: 20/133 up/down: 156/-773 (-617)
+
+Clang does it better and generates the same code before/after starting
+from -O1, except that with the ALIGN() approach it uses %edx and thus
+still saves some bytes:
+
+add/remove: 0/0 grow/shrink: 9/133 up/down: 18/-538 (-520)
+
+Note that we can't expand DIV_ROUND_UP() by adding a check and using
+this approach there, as it's used in array declarations where
+expressions are not allowed.
+Add this helper to tools/ as well.
+
+Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
+Acked-by: Yury Norov <yury.norov@gmail.com>
+Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/s390/cio/idset.c     |    2 +-
+ include/linux/bitmap.h       |    8 +++++---
+ include/linux/cpumask.h      |    2 +-
+ tools/include/linux/bitmap.h |    7 ++++---
+ 4 files changed, 11 insertions(+), 8 deletions(-)
+
+--- a/drivers/s390/cio/idset.c
++++ b/drivers/s390/cio/idset.c
+@@ -18,7 +18,7 @@ struct idset {
+ 
+ static inline unsigned long bitmap_size(int num_ssid, int num_id)
+ {
+-      return BITS_TO_LONGS(num_ssid * num_id) * sizeof(unsigned long);
++      return bitmap_size(size_mul(num_ssid, num_id));
+ }
+ 
+ static struct idset *idset_new(int num_ssid, int num_id)
+--- a/include/linux/bitmap.h
++++ b/include/linux/bitmap.h
+@@ -212,12 +212,14 @@ extern int bitmap_print_to_pagebuf(bool
+ #define small_const_nbits(nbits) \
+       (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG && (nbits) > 0)
+ 
++#define bitmap_size(nbits)    (ALIGN(nbits, BITS_PER_LONG) / BITS_PER_BYTE)
++
+ static inline void bitmap_zero(unsigned long *dst, unsigned int nbits)
+ {
+       if (small_const_nbits(nbits))
+               *dst = 0UL;
+       else {
+-              unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
++              unsigned int len = bitmap_size(nbits);
+               memset(dst, 0, len);
+       }
+ }
+@@ -227,7 +229,7 @@ static inline void bitmap_fill(unsigned
+       if (small_const_nbits(nbits))
+               *dst = ~0UL;
+       else {
+-              unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
++              unsigned int len = bitmap_size(nbits);
+               memset(dst, 0xff, len);
+       }
+ }
+@@ -238,7 +240,7 @@ static inline void bitmap_copy(unsigned
+       if (small_const_nbits(nbits))
+               *dst = *src;
+       else {
+-              unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
++              unsigned int len = bitmap_size(nbits);
+               memcpy(dst, src, len);
+       }
+ }
+--- a/include/linux/cpumask.h
++++ b/include/linux/cpumask.h
+@@ -656,7 +656,7 @@ static inline int cpulist_parse(const ch
+  */
+ static inline unsigned int cpumask_size(void)
+ {
+-      return BITS_TO_LONGS(nr_cpumask_bits) * sizeof(long);
++      return bitmap_size(nr_cpumask_bits);
+ }
+ 
+ /*
+--- a/tools/include/linux/bitmap.h
++++ b/tools/include/linux/bitmap.h
+@@ -27,13 +27,14 @@ int __bitmap_and(unsigned long *dst, con
+ #define small_const_nbits(nbits) \
+       (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG)
+ 
++#define bitmap_size(nbits)    (ALIGN(nbits, BITS_PER_LONG) / BITS_PER_BYTE)
++
+ static inline void bitmap_zero(unsigned long *dst, int nbits)
+ {
+       if (small_const_nbits(nbits))
+               *dst = 0UL;
+       else {
+-              int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
+-              memset(dst, 0, len);
++              memset(dst, 0, bitmap_size(nbits));
+       }
+ }
+ 
+@@ -119,7 +120,7 @@ static inline int test_and_clear_bit(int
+  */
+ static inline unsigned long *bitmap_alloc(int nbits)
+ {
+-      return calloc(1, BITS_TO_LONGS(nbits) * sizeof(unsigned long));
++      return calloc(1, bitmap_size(nbits));
+ }
+ 
+ /*

diff --git a/queue-4.19/fix-bitmap-corruption-on-close_range-with-close_range_unshare.patch b/queue-4.19/fix-bitmap-corruption-on-close_range-with-close_range_unshare.patch
index cd10ac83fc6bc5d39b19b346278b4f5f2a7f41eb..96b5864c5b263be2345256e5f9c394882e63a172 100644 (file)
--- a/queue-4.19/fix-bitmap-corruption-on-close_range-with-close_range_unshare.patch
+++ b/queue-4.19/fix-bitmap-corruption-on-close_range-with-close_range_unshare.patch
@@ -120,7 +120,7 @@ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
        new_fds = new_fdt->fd;
 --- a/include/linux/bitmap.h
 +++ b/include/linux/bitmap.h
-@@ -254,6 +254,18 @@ static inline void bitmap_copy_clear_tai
+@@ -256,6 +256,18 @@ static inline void bitmap_copy_clear_tai
                dst[nbits / BITS_PER_LONG] &= BITMAP_LAST_WORD_MASK(nbits);
  }
  

diff --git a/queue-4.19/series b/queue-4.19/series
index 6803eea792c32853fbd89347b37f0087c645f287..ded9034d4c1815dd0fe93eb7ae2b3c94ef104e37 100644 (file)
--- a/queue-4.19/series
+++ b/queue-4.19/series
@@ -4,4 +4,5 @@ xhci-fix-panther-point-null-pointer-deref-at-full-speed-re-enumeration.patch
 arm64-acpi-numa-initialize-all-values-of-acpi_early_node_map-to-numa_no_node.patch
 dm-resume-don-t-return-einval-when-signalled.patch
 dm-persistent-data-fix-memory-allocation-failure.patch
+bitmap-introduce-generic-optimized-bitmap_size.patch
 fix-bitmap-corruption-on-close_range-with-close_range_unshare.patch