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| author | kaf24@firebug.cl.cam.ac.uk <kaf24@firebug.cl.cam.ac.uk> | 2006-03-23 17:17:08 +0100 |
|---|---|---|
| committer | kaf24@firebug.cl.cam.ac.uk <kaf24@firebug.cl.cam.ac.uk> | 2006-03-23 17:17:08 +0100 |
| commit | a220cd9bebd1249df1708716995a4e95e142392a (patch) | |
| tree | fcff46d9e8c810f7ae8b0938c6bbc218aec64e10 /xen/common/gdbstub.c | |
| parent | 3b214d9b38158d1cd18790b67b5a27fd57cb9955 (diff) | |
| download | xen-a220cd9bebd1249df1708716995a4e95e142392a.tar.gz xen-a220cd9bebd1249df1708716995a4e95e142392a.tar.bz2 xen-a220cd9bebd1249df1708716995a4e95e142392a.zip | |
Reduce spin-waiting in Xen serial driver:
1. Split the serial port lock into receiver and transmitter locks.
2. In the ns16550 interrupt, only call the generic serial service
routines if there is receive (or transmit) work to do.
3. In the generic transmit ISR, avoid long spin-waits by *trying*
to take the transmitter lock and, if that fails, check again
whether the transmitter is empty. This will allow us to bail
bail quickly if there is a long-term lock holder stuffing lots
of bytes.
Also, gdbstub should be setting its serial handle in synchronous mode,
just for sanity.
Signed-off-by: Keir Fraser <keir@xensource.com>
Diffstat (limited to 'xen/common/gdbstub.c')
| -rw-r--r-- | xen/common/gdbstub.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/xen/common/gdbstub.c b/xen/common/gdbstub.c index fe51f79d35..8934122925 100644 --- a/xen/common/gdbstub.c +++ b/xen/common/gdbstub.c @@ -562,6 +562,7 @@ initialise_gdb(void) gdb_ctx->serhnd = serial_parse_handle(opt_gdb); if ( gdb_ctx->serhnd != -1 ) printk("GDB stub initialised.\n"); + serial_start_sync(gdb_ctx->serhnd); } /* |