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| author | scottl <scottl@FreeBSD.org> | 2013-07-30 23:26:05 +0000 |
|---|---|---|
| committer | scottl <scottl@FreeBSD.org> | 2013-07-30 23:26:05 +0000 |
| commit | 0eaffce7b350a432506f61d1240b4021dfced858 (patch) | |
| tree | 60c2d9f5e9fd2f5d373f58c5e67f4dc9baf09de0 /sys/kern/uipc_syscalls.c | |
| parent | d13c0062851638685f23ad2a414ca3b0e71ba340 (diff) | |
| download | FreeBSD-src-0eaffce7b350a432506f61d1240b4021dfced858.zip FreeBSD-src-0eaffce7b350a432506f61d1240b4021dfced858.tar.gz | |
Create a knob, kern.ipc.sfreadahead, that allows one to tune the amount of
readahead that sendfile() will do. Default remains the same.
Obtained from: Netflix
MFC after: 3 days
Diffstat (limited to 'sys/kern/uipc_syscalls.c')
| -rw-r--r-- | sys/kern/uipc_syscalls.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/sys/kern/uipc_syscalls.c b/sys/kern/uipc_syscalls.c index 46ceef2..07e169e 100644 --- a/sys/kern/uipc_syscalls.c +++ b/sys/kern/uipc_syscalls.c @@ -122,6 +122,7 @@ counter_u64_t sfstat[sizeof(struct sfstat) / sizeof(uint64_t)]; int nsfbufs; int nsfbufspeak; int nsfbufsused; +static int sfreadahead = MAXPHYS / MAXBSIZE; SYSCTL_INT(_kern_ipc, OID_AUTO, nsfbufs, CTLFLAG_RDTUN, &nsfbufs, 0, "Maximum number of sendfile(2) sf_bufs available"); @@ -129,6 +130,9 @@ SYSCTL_INT(_kern_ipc, OID_AUTO, nsfbufspeak, CTLFLAG_RD, &nsfbufspeak, 0, "Number of sendfile(2) sf_bufs at peak usage"); SYSCTL_INT(_kern_ipc, OID_AUTO, nsfbufsused, CTLFLAG_RD, &nsfbufsused, 0, "Number of sendfile(2) sf_bufs in use"); +SYSCTL_INT(_kern_ipc, OID_AUTO, sfreadahead, CTLFLAG_RW, &sfreadahead, 0, + "Number of sendfile(2) read-ahead MAXBSIZE blocks"); + static void sfstat_init(const void *unused) @@ -2240,6 +2244,7 @@ retry_space: error = EBUSY; else { ssize_t resid; + int readahead = sfreadahead * MAXBSIZE; /* * Ensure that our page is still around @@ -2255,9 +2260,9 @@ retry_space: * wrong, but is consistent with our original * implementation. */ - error = vn_rdwr(UIO_READ, vp, NULL, MAXBSIZE, + error = vn_rdwr(UIO_READ, vp, NULL, readahead, trunc_page(off), UIO_NOCOPY, IO_NODELOCKED | - IO_VMIO | ((MAXBSIZE / bsize) << IO_SEQSHIFT), + IO_VMIO | ((readahead / bsize) << IO_SEQSHIFT), td->td_ucred, NOCRED, &resid, td); VM_OBJECT_WLOCK(obj); vm_page_io_finish(pg); |
