#include #include #include /* * This implements the binary GCD algorithm. (Often attributed to Stein, * but as Knuth has noted, appears in a first-century Chinese math text.) * * This is faster than the division-based algorithm even on x86, which * has decent hardware division. */ #if !defined(CONFIG_CPU_NO_EFFICIENT_FFS) && !defined(CPU_NO_EFFICIENT_FFS) /* If __ffs is available, the even/odd algorithm benchmarks slower. */ unsigned long gcd(unsigned long a, unsigned long b) { unsigned long r = a | b; if (!a || !b) return r; b >>= __ffs(b); if (b == 1) return r & -r; for (;;) { a >>= __ffs(a); if (a == 1) return r & -r; if (a == b) return a << __ffs(r); if (a < b) swap(a, b); a -= b; } } #else /* If normalization is done by loops, the even/odd algorithm is a win. */ unsigned long gcd(unsigned long a, unsigned long b) { unsigned long r = a | b; if (!a || !b) return r; /* Isolate lsbit of r */ r &= -r; while (!(b & r)) b >>= 1; if (b == r) return r; for (;;) { while (!(a & r)) a >>= 1; if (a == r) return r; if (a == b) return a; if (a < b) swap(a, b); a -= b; a >>= 1; if (a & r) a += b; a >>= 1; } } #endif EXPORT_SYMBOL_GPL(gcd); ket-loop-back'>packet-loop-back net-next plumbingsTobias Klauser
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authorLinus Torvalds <torvalds@linux-foundation.org>2017-01-27 12:44:32 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-01-27 12:44:32 -0800
commit3365135d43f861003555c963b309672d053a2228 (patch)
treebfef4adec5da118bf1b3df7e5cff74f45af9e02d /include/trace/events/sched.h
parent5906374446386fd16fe562b042429d905d231ec3 (diff)
parente0d76fa4475ef2cf4b52d18588b8ce95153d021b (diff)
Merge tag 'xfs-for-linus-4.10-rc6-5' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull xfs uodates from Darrick Wong: "I have some more fixes this week: better input validation, corruption avoidance, build fixes, memory leak fixes, and a couple from Christoph to avoid an ENOSPC failure. Summary: - Fix race conditions in the CoW code - Fix some incorrect input validation checks - Avoid crashing fs by running out of space when freeing inodes - Fix toctou race wrt whether or not an inode has an attr - Fix build error on arm - Fix page refcount corruption when readahead fails - Don't corrupt userspace in the bmap ioctl" * tag 'xfs-for-linus-4.10-rc6-5' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: xfs: prevent quotacheck from overloading inode lru xfs: fix bmv_count confusion w/ shared extents xfs: clear _XBF_PAGES from buffers when readahead page xfs: extsize hints are not unlikely in xfs_bmap_btalloc xfs: remove racy hasattr check from attr ops xfs: use per-AG reservations for the finobt xfs: only update mount/resv fields on success in __xfs_ag_resv_init xfs: verify dirblocklog correctly xfs: fix COW writeback race
Diffstat (limited to 'include/trace/events/sched.h')