fs: optimise kiocb_set_rw_flags() (1752f0ad) · Commits · 戴 / test

Use a local var to collect flags in kiocb_set_rw_flags(). That spares some memory writes and allows to replace most of the jumps with MOVEcc. Signed-off-by:

Pavel Begunkov <asml.silence@gmail.com> Reviewed-by:

Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by:

Jens Axboe <axboe@kernel.dk>

include/linux/fs.h

+11 −5

Original line number	Diff line number	Diff line
		@@ -3446,22 +3446,28 @@ static inline int iocb_flags(struct file *file)

		static inline int kiocb_set_rw_flags(struct kiocb *ki, rwf_t flags)
		{
		int kiocb_flags = 0;

		if (!flags)
		return 0;
		if (unlikely(flags & ~RWF_SUPPORTED))
		return -EOPNOTSUPP;

		if (flags & RWF_NOWAIT) {
		if (!(ki->ki_filp->f_mode & FMODE_NOWAIT))
		return -EOPNOTSUPP;
		ki->ki_flags \|= IOCB_NOWAIT;
		kiocb_flags \|= IOCB_NOWAIT;
		}
		if (flags & RWF_HIPRI)
		ki->ki_flags \|= IOCB_HIPRI;
		kiocb_flags \|= IOCB_HIPRI;
		if (flags & RWF_DSYNC)
		ki->ki_flags \|= IOCB_DSYNC;
		kiocb_flags \|= IOCB_DSYNC;
		if (flags & RWF_SYNC)
		ki->ki_flags \|= (IOCB_DSYNC \| IOCB_SYNC);
		kiocb_flags \|= (IOCB_DSYNC \| IOCB_SYNC);
		if (flags & RWF_APPEND)
		ki->ki_flags \|= IOCB_APPEND;
		kiocb_flags \|= IOCB_APPEND;

		ki->ki_flags \|= kiocb_flags;
		return 0;
		}

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