Gitweb: http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=21371f768bf7127ee45bfaadd17899df6a439e8f Commit: 21371f768bf7127ee45bfaadd17899df6a439e8f Parent: b15c4bcd15741b31019379298edfca28dc78029d Author: Eric Dumazet <[EMAIL PROTECTED]> AuthorDate: Mon Dec 24 20:57:56 2007 -0800 Committer: David S. Miller <[EMAIL PROTECTED]> CommitDate: Mon Jan 28 15:00:05 2008 -0800
[SOCK] Avoid divides in sk_stream_pages() and __sk_stream_mem_reclaim() sk_forward_alloc being signed, we should take care of divides by SK_STREAM_MEM_QUANTUM we do in sk_stream_pages() and __sk_stream_mem_reclaim() This patchs introduces SK_STREAM_MEM_QUANTUM_SHIFT, defined as ilog2(SK_STREAM_MEM_QUANTUM), to be able to use right shifts instead of plain divides. This should help compiler to choose right shifts instead of expensive divides (as seen with CONFIG_CC_OPTIMIZE_FOR_SIZE=y on x86) Signed-off-by: Eric Dumazet <[EMAIL PROTECTED]> Signed-off-by: David S. Miller <[EMAIL PROTECTED]> --- include/net/sock.h | 3 ++- net/core/stream.c | 2 +- 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/include/net/sock.h b/include/net/sock.h index e178b49..d27ba6f 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -716,10 +716,11 @@ extern void __sk_stream_mem_reclaim(struct sock *sk); extern int sk_stream_mem_schedule(struct sock *sk, int size, int kind); #define SK_STREAM_MEM_QUANTUM ((int)PAGE_SIZE) +#define SK_STREAM_MEM_QUANTUM_SHIFT ilog2(SK_STREAM_MEM_QUANTUM) static inline int sk_stream_pages(int amt) { - return DIV_ROUND_UP(amt, SK_STREAM_MEM_QUANTUM); + return (amt + SK_STREAM_MEM_QUANTUM - 1) >> SK_STREAM_MEM_QUANTUM_SHIFT; } static inline void sk_stream_mem_reclaim(struct sock *sk) diff --git a/net/core/stream.c b/net/core/stream.c index 5586879..bf188ff 100644 --- a/net/core/stream.c +++ b/net/core/stream.c @@ -196,7 +196,7 @@ EXPORT_SYMBOL(sk_stream_error); void __sk_stream_mem_reclaim(struct sock *sk) { - atomic_sub(sk->sk_forward_alloc / SK_STREAM_MEM_QUANTUM, + atomic_sub(sk->sk_forward_alloc >> SK_STREAM_MEM_QUANTUM_SHIFT, sk->sk_prot->memory_allocated); sk->sk_forward_alloc &= SK_STREAM_MEM_QUANTUM - 1; if (*sk->sk_prot->memory_pressure && - To unsubscribe from this list: send the line "unsubscribe git-commits-head" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html