From 82f77991679c05d93c01888bb79c571c7fa9142f Mon Sep 17 00:00:00 2001 From: Krutika Dhananjay Date: Tue, 7 Jun 2016 16:27:34 +0530 Subject: libglusterfs: Implement API that provides page-aligned iobufs Backport of: http://review.gluster.org/14672 One of the consumers of a page aligned buffer would be posix's readv fop on O_DIRECT fds. Today the way it works is by getting a page-aligned buffer through calloc, pread()ing into this buffer and then copying its contents into a newly created iobuf's ptr. This results in an extra memcpy() which can be avoided if we could implement an api that would return an iobuf whose ptr is page-aligned. That way the iobuf->ptr can be directly passed to sys_pread() as a parameter by posix translator. Change-Id: I7f64419461db387e4ab6b0e03c90471744aa56e1 BUG: 1351025 Signed-off-by: Krutika Dhananjay Reviewed-on: http://review.gluster.org/14825 Smoke: Gluster Build System NetBSD-regression: NetBSD Build System CentOS-regression: Gluster Build System Reviewed-by: Pranith Kumar Karampuri --- libglusterfs/src/iobuf.c | 35 +++++++++++++++++++++++++++++++ libglusterfs/src/iobuf.h | 4 ++++ xlators/storage/posix/src/posix.c | 44 ++++++++++----------------------------- 3 files changed, 50 insertions(+), 33 deletions(-) diff --git a/libglusterfs/src/iobuf.c b/libglusterfs/src/iobuf.c index d1eb0acaf5e..17cd68fc206 100644 --- a/libglusterfs/src/iobuf.c +++ b/libglusterfs/src/iobuf.c @@ -678,6 +678,36 @@ unlock: return iobuf; } +struct iobuf * +iobuf_get_page_aligned (struct iobuf_pool *iobuf_pool, size_t page_size, + size_t align_size) +{ + size_t req_size = 0; + struct iobuf *iobuf = NULL; + + req_size = page_size; + + if (req_size == 0) { + req_size = iobuf_pool->default_page_size; + } + + iobuf = iobuf_get2 (iobuf_pool, req_size + align_size); + /* If std allocation was used, then free_ptr will be non-NULL. In this + * case, we do not want to modify the original free_ptr. + * On the other hand, if the buf was gotten through the available + * arenas, then we use iobuf->free_ptr to store the original + * pointer to the offset into the mmap'd block of memory and in turn + * reuse iobuf->ptr to hold the page-aligned address. And finally, in + * iobuf_put(), we copy iobuf->free_ptr into iobuf->ptr - back to where + * it was originally when __iobuf_get() returned this iobuf. + */ + if (!iobuf->free_ptr) + iobuf->free_ptr = iobuf->ptr; + iobuf->ptr = GF_ALIGN_BUF (iobuf->ptr, align_size); + + return iobuf; +} + struct iobuf * iobuf_get (struct iobuf_pool *iobuf_pool) { @@ -745,6 +775,11 @@ __iobuf_put (struct iobuf *iobuf, struct iobuf_arena *iobuf_arena) list_del_init (&iobuf->list); iobuf_arena->active_cnt--; + if (iobuf->free_ptr) { + iobuf->ptr = iobuf->free_ptr; + iobuf->free_ptr = NULL; + } + list_add (&iobuf->list, &iobuf_arena->passive.list); iobuf_arena->passive_cnt++; diff --git a/libglusterfs/src/iobuf.h b/libglusterfs/src/iobuf.h index 7e5cfe37a28..1578ceb84dd 100644 --- a/libglusterfs/src/iobuf.h +++ b/libglusterfs/src/iobuf.h @@ -169,4 +169,8 @@ void iobuf_stats_dump (struct iobuf_pool *iobuf_pool); struct iobuf * iobuf_get2 (struct iobuf_pool *iobuf_pool, size_t page_size); + +struct iobuf * +iobuf_get_page_aligned (struct iobuf_pool *iobuf_pool, size_t page_size, + size_t align_size); #endif /* !_IOBUF_H_ */ diff --git a/xlators/storage/posix/src/posix.c b/xlators/storage/posix/src/posix.c index 2320bf13449..8784571470f 100644 --- a/xlators/storage/posix/src/posix.c +++ b/xlators/storage/posix/src/posix.c @@ -3042,8 +3042,6 @@ posix_readv (call_frame_t *frame, xlator_t *this, int32_t op_ret = -1; int32_t op_errno = 0; int _fd = -1; - char *buf = NULL; - char *alloc_buf = NULL; struct posix_private * priv = NULL; struct iobuf * iobuf = NULL; struct iobref * iobref = NULL; @@ -3075,42 +3073,23 @@ posix_readv (call_frame_t *frame, xlator_t *this, goto out; } - iobuf = iobuf_get2 (this->ctx->iobuf_pool, size); + iobuf = iobuf_get_page_aligned (this->ctx->iobuf_pool, size, + ALIGN_SIZE); if (!iobuf) { op_errno = ENOMEM; goto out; } _fd = pfd->fd; - if (pfd->flags & O_DIRECT) { - alloc_buf = _page_aligned_alloc (size, &buf); - if (!alloc_buf) { - op_ret = -1; - op_errno = errno; - goto out; - } - - op_ret = sys_pread (_fd, buf, size, offset); - if (op_ret == -1) { - op_errno = errno; - gf_msg (this->name, GF_LOG_ERROR, errno, - P_MSG_READ_FAILED, "read failed on gfid=%s, " - "fd=%p, offset=%"PRIu64" size=%"GF_PRI_SIZET", " - "buf=%p", uuid_utoa (fd->inode->gfid), fd, - offset, size, buf); - goto out; - } - memcpy(iobuf->ptr, buf, size); - } else { - op_ret = sys_pread (_fd, iobuf->ptr, size, offset); - if (op_ret == -1) { - op_errno = errno; - gf_msg (this->name, GF_LOG_ERROR, errno, P_MSG_READ_FAILED, - "read failed on gfid=%s, fd=%p, offset=%"PRIu64" " - "size=%"GF_PRI_SIZET"", uuid_utoa (fd->inode->gfid), fd, - offset, size); - goto out; - } + op_ret = sys_pread (_fd, iobuf->ptr, size, offset); + if (op_ret == -1) { + op_errno = errno; + gf_msg (this->name, GF_LOG_ERROR, errno, + P_MSG_READ_FAILED, "read failed on gfid=%s, " + "fd=%p, offset=%"PRIu64" size=%"GF_PRI_SIZET", " + "buf=%p", uuid_utoa (fd->inode->gfid), fd, + offset, size, iobuf->ptr); + goto out; } LOCK (&priv->lock); @@ -3153,7 +3132,6 @@ out: iobref_unref (iobref); if (iobuf) iobuf_unref (iobuf); - GF_FREE (alloc_buf); return 0; } -- cgit