From mboxrd@z Thu Jan 1 00:00:00 1970 From: piaojun Message-ID: <5D48EEAB.7000100@huawei.com> Date: Tue, 6 Aug 2019 11:06:19 +0800 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Subject: [Virtio-fs] [PATCH RFC] virtiofs: improve io bandwidth by replacing pwrite with pwritev List-Id: Development discussions about virtio-fs List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: virtio-fs@redhat.com >>From my test, write bandwidth will be improved greatly by replacing pwrite with pwritev, and the test result as below: --- pwrite: # fio -direct=1 -time_based -iodepth=64 -rw=randwrite -ioengine=libaio -bs=1M -size=1G -numjob=16 -runtime=30 -group_reporting -name=file -filename=/mnt/virtiofs/file file: (g=0): rw=randwrite, bs=1M-1M/1M-1M/1M-1M, ioengine=libaio, iodepth=64 ... fio-2.13 Starting 16 processes Jobs: 16 (f=16): [w(16)] [100.0% done] [0KB/886.0MB/0KB /s] [0/886/0 iops] [eta 00m:00s] file: (groupid=0, jobs=16): err= 0: pid=5799: Tue Aug 6 18:48:26 2019 write: io=26881MB, bw=916988KB/s, iops=895, runt= 30018msec pwritev: # fio -direct=1 -time_based -iodepth=64 -rw=randwrite -ioengine=libaio -bs=1M -size=1G -numjob=16 -runtime=30 -group_reporting -name=file -filename=/mnt/virtiofs/file file: (g=0): rw=randwrite, bs=1M-1M/1M-1M/1M-1M, ioengine=libaio, iodepth=64 ... fio-2.13 Starting 16 processes Jobs: 16 (f=16): [w(16)] [100.0% done] [0KB/1793MB/0KB /s] [0/1793/0 iops] [eta 00m:00s] file: (groupid=0, jobs=16): err= 0: pid=6328: Tue Aug 6 18:22:17 2019 write: io=52775MB, bw=1758.7MB/s, iops=1758, runt= 30009msec --- This patch introduces writev and pwritev and clean up *fuse_buf_copy* and its related code. I wonder if I'd better split it into two patches or other modification. I'm very glad for your suggestions. Thanks, Jun Signed-off-by: Jun Piao --- contrib/virtiofsd/buffer.c | 310 ++++--------------------------------- contrib/virtiofsd/fuse_common.h | 15 +- contrib/virtiofsd/passthrough_ll.c | 2 +- contrib/virtiofsd/seccomp.c | 2 + 4 files changed, 37 insertions(+), 292 deletions(-) diff --git a/contrib/virtiofsd/buffer.c b/contrib/virtiofsd/buffer.c index 655be137..78f8d3e 100644 --- a/contrib/virtiofsd/buffer.c +++ b/contrib/virtiofsd/buffer.c @@ -15,6 +15,7 @@ #include #include #include +#include size_t fuse_buf_size(const struct fuse_bufvec *bufv) { @@ -31,299 +32,40 @@ size_t fuse_buf_size(const struct fuse_bufvec *bufv) return size; } -static size_t min_size(size_t s1, size_t s2) +ssize_t fuse_buf_writev(fuse_req_t req, + struct fuse_bufvec *out_buf, + struct fuse_bufvec *in_buf, + enum fuse_buf_copy_flags flags) { - return s1 < s2 ? s1 : s2; -} - -static ssize_t fuse_buf_write(const struct fuse_buf *dst, size_t dst_off, - const struct fuse_buf *src, size_t src_off, - size_t len) -{ - ssize_t res = 0; - size_t copied = 0; - - assert(!(src->flags & FUSE_BUF_PHYS_ADDR)); - while (len) { - if (dst->flags & FUSE_BUF_FD_SEEK) { - res = pwrite(dst->fd, src->mem + src_off, len, - dst->pos + dst_off); - } else { - res = write(dst->fd, src->mem + src_off, len); - } - if (res == -1) { - if (!copied) - return -errno; - break; - } - if (res == 0) - break; - - copied += res; - if (!(dst->flags & FUSE_BUF_FD_RETRY)) - break; - - src_off += res; - dst_off += res; - len -= res; - } - - return copied; -} - -static ssize_t fuse_buf_read(const struct fuse_buf *dst, size_t dst_off, - const struct fuse_buf *src, size_t src_off, - size_t len) -{ - ssize_t res = 0; - size_t copied = 0; - - while (len) { - if (src->flags & FUSE_BUF_FD_SEEK) { - res = pread(src->fd, dst->mem + dst_off, len, - src->pos + src_off); - } else { - res = read(src->fd, dst->mem + dst_off, len); - } - if (res == -1) { - if (!copied) - return -errno; - break; - } - if (res == 0) - break; - - copied += res; - if (!(src->flags & FUSE_BUF_FD_RETRY)) - break; - - dst_off += res; - src_off += res; - len -= res; - } - - return copied; -} - -static ssize_t fuse_buf_fd_to_fd(const struct fuse_buf *dst, size_t dst_off, - const struct fuse_buf *src, size_t src_off, - size_t len) -{ - char buf[4096]; - struct fuse_buf tmp = { - .size = sizeof(buf), - .flags = 0, - }; - ssize_t res; - size_t copied = 0; - - tmp.mem = buf; - - while (len) { - size_t this_len = min_size(tmp.size, len); - size_t read_len; - - res = fuse_buf_read(&tmp, 0, src, src_off, this_len); - if (res < 0) { - if (!copied) - return res; - break; - } - if (res == 0) - break; - - read_len = res; - res = fuse_buf_write(dst, dst_off, &tmp, 0, read_len); - if (res < 0) { - if (!copied) - return res; - break; - } - if (res == 0) - break; - - copied += res; - - if (res < this_len) - break; - - dst_off += res; - src_off += res; - len -= res; - } - - return copied; -} - -#ifdef HAVE_SPLICE -static ssize_t fuse_buf_splice(const struct fuse_buf *dst, size_t dst_off, - const struct fuse_buf *src, size_t src_off, - size_t len, enum fuse_buf_copy_flags flags) -{ - int splice_flags = 0; - off_t *srcpos = NULL; - off_t *dstpos = NULL; - off_t srcpos_val; - off_t dstpos_val; - ssize_t res; - size_t copied = 0; - - if (flags & FUSE_BUF_SPLICE_MOVE) - splice_flags |= SPLICE_F_MOVE; - if (flags & FUSE_BUF_SPLICE_NONBLOCK) - splice_flags |= SPLICE_F_NONBLOCK; - - if (src->flags & FUSE_BUF_FD_SEEK) { - srcpos_val = src->pos + src_off; - srcpos = &srcpos_val; - } - if (dst->flags & FUSE_BUF_FD_SEEK) { - dstpos_val = dst->pos + dst_off; - dstpos = &dstpos_val; - } - - while (len) { - res = splice(src->fd, srcpos, dst->fd, dstpos, len, - splice_flags); - if (res == -1) { - if (copied) - break; - - if (errno != EINVAL || (flags & FUSE_BUF_FORCE_SPLICE)) - return -errno; - - /* Maybe splice is not supported for this combination */ - return fuse_buf_fd_to_fd(dst, dst_off, src, src_off, - len); - } - if (res == 0) - break; - - copied += res; - if (!(src->flags & FUSE_BUF_FD_RETRY) && - !(dst->flags & FUSE_BUF_FD_RETRY)) { - break; - } - - len -= res; - } - - return copied; -} -#else -static ssize_t fuse_buf_splice(const struct fuse_buf *dst, size_t dst_off, - const struct fuse_buf *src, size_t src_off, - size_t len, enum fuse_buf_copy_flags flags) -{ - (void) flags; - - return fuse_buf_fd_to_fd(dst, dst_off, src, src_off, len); -} -#endif - - -static ssize_t fuse_buf_copy_one(fuse_req_t req, - const struct fuse_buf *dst, size_t dst_off, - const struct fuse_buf *src, size_t src_off, - size_t len, enum fuse_buf_copy_flags flags) -{ - int src_is_fd = src->flags & FUSE_BUF_IS_FD; - int dst_is_fd = dst->flags & FUSE_BUF_IS_FD; - int src_is_phys = src->flags & FUSE_BUF_PHYS_ADDR; - int dst_is_phys = src->flags & FUSE_BUF_PHYS_ADDR; - - if (src_is_phys && !src_is_fd && dst_is_fd) { - return fuse_virtio_write(req, dst, dst_off, src, src_off, len); - } - - assert(!src_is_phys && !dst_is_phys); - if (!src_is_fd && !dst_is_fd) { - void *dstmem = dst->mem + dst_off; - void *srcmem = src->mem + src_off; + ssize_t res, i, buf_index, iovcnt; + struct iovec * iov; + int fd = out_buf->buf[0].fd; + off_t pos = out_buf->buf[0].pos; - if (dstmem != srcmem) { - if (dstmem + len <= srcmem || srcmem + len <= dstmem) - memcpy(dstmem, srcmem, len); - else - memmove(dstmem, srcmem, len); - } - - return len; - } else if (!src_is_fd) { - return fuse_buf_write(dst, dst_off, src, src_off, len); - } else if (!dst_is_fd) { - return fuse_buf_read(dst, dst_off, src, src_off, len); - } else if (flags & FUSE_BUF_NO_SPLICE) { - return fuse_buf_fd_to_fd(dst, dst_off, src, src_off, len); - } else { - return fuse_buf_splice(dst, dst_off, src, src_off, len, flags); - } -} - -static const struct fuse_buf *fuse_bufvec_current(struct fuse_bufvec *bufv) -{ - if (bufv->idx < bufv->count) - return &bufv->buf[bufv->idx]; + if (in_buf->count > 2) + iovcnt = in_buf->count - 1; else - return NULL; -} + iovcnt = 1; -static int fuse_bufvec_advance(struct fuse_bufvec *bufv, size_t len) -{ - const struct fuse_buf *buf = fuse_bufvec_current(bufv); + iov = malloc(iovcnt * sizeof(struct iovec)); + if (!iov) + return -ENOMEM; - bufv->off += len; - assert(bufv->off <= buf->size); - if (bufv->off == buf->size) { - assert(bufv->idx < bufv->count); - bufv->idx++; - if (bufv->idx == bufv->count) - return 0; - bufv->off = 0; + for (i = 0, buf_index = 1; i < iovcnt; i++, buf_index++) { + iov[i].iov_base = in_buf->buf[buf_index].mem; + iov[i].iov_len = in_buf->buf[buf_index].size; } - return 1; -} -ssize_t fuse_buf_copy(fuse_req_t req, struct fuse_bufvec *dstv, struct fuse_bufvec *srcv, - enum fuse_buf_copy_flags flags) -{ - size_t copied = 0; - - if (dstv == srcv) - return fuse_buf_size(dstv); - - for (;;) { - const struct fuse_buf *src = fuse_bufvec_current(srcv); - const struct fuse_buf *dst = fuse_bufvec_current(dstv); - size_t src_len; - size_t dst_len; - size_t len; - ssize_t res; - - if (src == NULL || dst == NULL) - break; - - src_len = src->size - srcv->off; - dst_len = dst->size - dstv->off; - len = min_size(src_len, dst_len); - - res = fuse_buf_copy_one(req, dst, dstv->off, src, srcv->off, len, flags); - if (res < 0) { - if (!copied) - return res; - break; - } - copied += res; - - if (!fuse_bufvec_advance(srcv, res) || - !fuse_bufvec_advance(dstv, res)) - break; + if (flags & FUSE_BUF_FD_SEEK) + res = pwritev(fd, iov, iovcnt, pos); + else + res = writev(fd, iov, iovcnt); - if (res < len) - break; - } + if (res == -1 || res == 0) + res = -errno; - return copied; + free(iov); + return res; } void *fuse_mbuf_iter_advance(struct fuse_mbuf_iter *iter, size_t len) diff --git a/contrib/virtiofsd/fuse_common.h b/contrib/virtiofsd/fuse_common.h index 001e6d6..c715e52 100644 --- a/contrib/virtiofsd/fuse_common.h +++ b/contrib/virtiofsd/fuse_common.h @@ -717,17 +717,18 @@ struct fuse_bufvec { size_t fuse_buf_size(const struct fuse_bufvec *bufv); /** - * Copy data from one buffer vector to another + * Write data from one buffer vector to another * * @param req The request this copy is part of - * @param dst destination buffer vector - * @param src source buffer vector + * @param out_buf destination buffer vector + * @param in_buf source buffer vector * @param flags flags controlling the copy - * @return actual number of bytes copied or -errno on error + * @return actual number of bytes written or -errno on error */ -ssize_t fuse_buf_copy(fuse_req_t req, - struct fuse_bufvec *dst, struct fuse_bufvec *src, - enum fuse_buf_copy_flags flags); +ssize_t fuse_buf_writev(fuse_req_t req, + struct fuse_bufvec *out_buf, + struct fuse_bufvec *in_buf, + enum fuse_buf_copy_flags flags); /** * Memory buffer iterator diff --git a/contrib/virtiofsd/passthrough_ll.c b/contrib/virtiofsd/passthrough_ll.c index cc9c175..3082683 100644 --- a/contrib/virtiofsd/passthrough_ll.c +++ b/contrib/virtiofsd/passthrough_ll.c @@ -2023,7 +2023,7 @@ static void lo_write_buf(fuse_req_t req, fuse_ino_t ino, fuse_debug("lo_write_buf(ino=%" PRIu64 ", size=%zd, off=%lu)\n", ino, out_buf.buf[0].size, (unsigned long) off); - res = fuse_buf_copy(req, &out_buf, in_buf, 0); + res = fuse_buf_writev(req, &out_buf, in_buf, out_buf.buf[0].flags); if(res < 0) { fuse_reply_err(req, -res); } else { diff --git a/contrib/virtiofsd/seccomp.c b/contrib/virtiofsd/seccomp.c index 5f1c873..4bba30b 100644 --- a/contrib/virtiofsd/seccomp.c +++ b/contrib/virtiofsd/seccomp.c @@ -60,6 +60,7 @@ static const int syscall_whitelist[] = { SCMP_SYS(ppoll), SCMP_SYS(prctl), /* TODO restrict to just PR_SET_NAME? */ SCMP_SYS(preadv), + SCMP_SYS(pwritev), SCMP_SYS(pwrite64), SCMP_SYS(read), SCMP_SYS(readlinkat), @@ -78,6 +79,7 @@ static const int syscall_whitelist[] = { SCMP_SYS(unlinkat), SCMP_SYS(utimensat), SCMP_SYS(write), + SCMP_SYS(writev), }; /* Syscalls used when --syslog is enabled */ --