diff options
| author | Ming Lei <ming.lei@canonical.com> | 2016-05-30 09:34:32 -0400 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2016-06-09 12:02:47 -0400 |
| commit | 1bdc76aea1159a750846c2fc98e404403eb7d51c (patch) | |
| tree | eb61e4844ee2862fc43d396645224da2fa6fd177 /lib/iov_iter.c | |
| parent | 80f162ff061c9e280589bb1a1890c7fc21c932cd (diff) | |
iov_iter: use bvec iterator to implement iterate_bvec()
bvec has one native/mature iterator for long time, so not
necessary to use the reinvented wheel for iterating bvecs
in lib/iov_iter.c.
Two ITER_BVEC test cases are run:
- xfstest(-g auto) on loop dio/aio, no regression found
- swap file works well under extreme stress(stress-ng --all 64 -t
800 -v), and lots of OOMs are triggerd, and the whole
system still survives
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Tested-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'lib/iov_iter.c')
| -rw-r--r-- | lib/iov_iter.c | 45 |
1 files changed, 15 insertions, 30 deletions
diff --git a/lib/iov_iter.c b/lib/iov_iter.c index 0cd522753ff5..d67c8288d95d 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c | |||
| @@ -56,37 +56,24 @@ | |||
| 56 | n = wanted; \ | 56 | n = wanted; \ |
| 57 | } | 57 | } |
| 58 | 58 | ||
| 59 | #define iterate_bvec(i, n, __v, __p, skip, STEP) { \ | 59 | #define iterate_bvec(i, n, __v, __bi, skip, STEP) { \ |
| 60 | size_t wanted = n; \ | 60 | struct bvec_iter __start; \ |
| 61 | __p = i->bvec; \ | 61 | __start.bi_size = n; \ |
| 62 | __v.bv_len = min_t(size_t, n, __p->bv_len - skip); \ | 62 | __start.bi_bvec_done = skip; \ |
| 63 | if (likely(__v.bv_len)) { \ | 63 | __start.bi_idx = 0; \ |
| 64 | __v.bv_page = __p->bv_page; \ | 64 | for_each_bvec(__v, i->bvec, __bi, __start) { \ |
| 65 | __v.bv_offset = __p->bv_offset + skip; \ | 65 | if (!__v.bv_len) \ |
| 66 | (void)(STEP); \ | ||
| 67 | skip += __v.bv_len; \ | ||
| 68 | n -= __v.bv_len; \ | ||
| 69 | } \ | ||
| 70 | while (unlikely(n)) { \ | ||
| 71 | __p++; \ | ||
| 72 | __v.bv_len = min_t(size_t, n, __p->bv_len); \ | ||
| 73 | if (unlikely(!__v.bv_len)) \ | ||
| 74 | continue; \ | 66 | continue; \ |
| 75 | __v.bv_page = __p->bv_page; \ | ||
| 76 | __v.bv_offset = __p->bv_offset; \ | ||
| 77 | (void)(STEP); \ | 67 | (void)(STEP); \ |
| 78 | skip = __v.bv_len; \ | ||
| 79 | n -= __v.bv_len; \ | ||
| 80 | } \ | 68 | } \ |
| 81 | n = wanted; \ | ||
| 82 | } | 69 | } |
| 83 | 70 | ||
| 84 | #define iterate_all_kinds(i, n, v, I, B, K) { \ | 71 | #define iterate_all_kinds(i, n, v, I, B, K) { \ |
| 85 | size_t skip = i->iov_offset; \ | 72 | size_t skip = i->iov_offset; \ |
| 86 | if (unlikely(i->type & ITER_BVEC)) { \ | 73 | if (unlikely(i->type & ITER_BVEC)) { \ |
| 87 | const struct bio_vec *bvec; \ | ||
| 88 | struct bio_vec v; \ | 74 | struct bio_vec v; \ |
| 89 | iterate_bvec(i, n, v, bvec, skip, (B)) \ | 75 | struct bvec_iter __bi; \ |
| 76 | iterate_bvec(i, n, v, __bi, skip, (B)) \ | ||
| 90 | } else if (unlikely(i->type & ITER_KVEC)) { \ | 77 | } else if (unlikely(i->type & ITER_KVEC)) { \ |
| 91 | const struct kvec *kvec; \ | 78 | const struct kvec *kvec; \ |
| 92 | struct kvec v; \ | 79 | struct kvec v; \ |
| @@ -104,15 +91,13 @@ | |||
| 104 | if (i->count) { \ | 91 | if (i->count) { \ |
| 105 | size_t skip = i->iov_offset; \ | 92 | size_t skip = i->iov_offset; \ |
| 106 | if (unlikely(i->type & ITER_BVEC)) { \ | 93 | if (unlikely(i->type & ITER_BVEC)) { \ |
| 107 | const struct bio_vec *bvec; \ | 94 | const struct bio_vec *bvec = i->bvec; \ |
| 108 | struct bio_vec v; \ | 95 | struct bio_vec v; \ |
| 109 | iterate_bvec(i, n, v, bvec, skip, (B)) \ | 96 | struct bvec_iter __bi; \ |
| 110 | if (skip == bvec->bv_len) { \ | 97 | iterate_bvec(i, n, v, __bi, skip, (B)) \ |
| 111 | bvec++; \ | 98 | i->bvec = __bvec_iter_bvec(i->bvec, __bi); \ |
| 112 | skip = 0; \ | 99 | i->nr_segs -= i->bvec - bvec; \ |
| 113 | } \ | 100 | skip = __bi.bi_bvec_done; \ |
| 114 | i->nr_segs -= bvec - i->bvec; \ | ||
| 115 | i->bvec = bvec; \ | ||
| 116 | } else if (unlikely(i->type & ITER_KVEC)) { \ | 101 | } else if (unlikely(i->type & ITER_KVEC)) { \ |
| 117 | const struct kvec *kvec; \ | 102 | const struct kvec *kvec; \ |
| 118 | struct kvec v; \ | 103 | struct kvec v; \ |