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author | Andres Lagar-Cavilla <andres@lagarcavilla.org> | 2012-03-01 16:41:39 +0000 |
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committer | Andres Lagar-Cavilla <andres@lagarcavilla.org> | 2012-03-01 16:41:39 +0000 |
commit | f140a8b192aa94dcd9356b558a12652b3c96d0f4 (patch) | |
tree | 927b0cd7ba972a338585b47255b426ef1fed9f33 /tools/misc | |
parent | 9f06a2e65888fc0972c977f3f951f41c3d17f22b (diff) | |
download | xen-f140a8b192aa94dcd9356b558a12652b3c96d0f4.tar.gz xen-f140a8b192aa94dcd9356b558a12652b3c96d0f4.tar.bz2 xen-f140a8b192aa94dcd9356b558a12652b3c96d0f4.zip |
Lowmemd: Simple demo code to show use of VIRQ_ENOMEM
Signed-off-by: Andres Lagar-Cavilla <andres@lagarcavilla.org>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Diffstat (limited to 'tools/misc')
-rw-r--r-- | tools/misc/Makefile | 7 | ||||
-rw-r--r-- | tools/misc/xen-lowmemd.c | 148 |
2 files changed, 153 insertions, 2 deletions
diff --git a/tools/misc/Makefile b/tools/misc/Makefile index 817398bc9b..bd9b017ad2 100644 --- a/tools/misc/Makefile +++ b/tools/misc/Makefile @@ -9,7 +9,7 @@ CFLAGS += $(CFLAGS_xeninclude) HDRS = $(wildcard *.h) TARGETS-y := xenperf xenpm xen-tmem-list-parse gtraceview gtracestat xenlockprof xenwatchdogd -TARGETS-$(CONFIG_X86) += xen-detect xen-hvmctx xen-hvmcrash +TARGETS-$(CONFIG_X86) += xen-detect xen-hvmctx xen-hvmcrash xen-lowmemd TARGETS-$(CONFIG_MIGRATE) += xen-hptool TARGETS := $(TARGETS-y) @@ -21,7 +21,7 @@ INSTALL_BIN-y := xencons INSTALL_BIN-$(CONFIG_X86) += xen-detect INSTALL_BIN := $(INSTALL_BIN-y) -INSTALL_SBIN-y := xm xen-bugtool xen-python-path xend xenperf xsview xenpm xen-tmem-list-parse gtraceview gtracestat xenlockprof xenwatchdogd xen-ringwatch +INSTALL_SBIN-y := xm xen-bugtool xen-python-path xend xenperf xsview xenpm xen-tmem-list-parse gtraceview gtracestat xenlockprof xenwatchdogd xen-ringwatch xen-lowmemd INSTALL_SBIN-$(CONFIG_X86) += xen-hvmctx xen-hvmcrash INSTALL_SBIN-$(CONFIG_MIGRATE) += xen-hptool INSTALL_SBIN := $(INSTALL_SBIN-y) @@ -70,6 +70,9 @@ xen-hptool: xen-hptool.o xenwatchdogd: xenwatchdogd.o $(CC) $(LDFLAGS) -o $@ $< $(LDLIBS_libxenctrl) $(APPEND_LDFLAGS) +xen-lowmemd: xen-lowmemd.o + $(CC) $(LDFLAGS) -o $@ $< $(LDLIBS_libxenctrl) $(LDLIBS_libxenstore) $(APPEND_LDFLAGS) + gtraceview: gtraceview.o $(CC) $(LDFLAGS) -o $@ $< $(CURSES_LIBS) $(APPEND_LDFLAGS) diff --git a/tools/misc/xen-lowmemd.c b/tools/misc/xen-lowmemd.c new file mode 100644 index 0000000000..42098e4d6f --- /dev/null +++ b/tools/misc/xen-lowmemd.c @@ -0,0 +1,148 @@ +/* + * xen-lowmemd: demo VIRQ_ENOMEM + * Andres Lagar-Cavilla (GridCentric Inc.) + */ + +#include <stdio.h> +#include <xenctrl.h> +#include <xs.h> +#include <stdlib.h> +#include <string.h> + +static evtchn_port_t virq_port = -1; +static xc_evtchn *xce_handle = NULL; +static xc_interface *xch = NULL; +static struct xs_handle *xs_handle = NULL; + +void cleanup(void) +{ + if (virq_port > -1) + xc_evtchn_unbind(xce_handle, virq_port); + if (xce_handle) + xc_evtchn_close(xce_handle); + if (xch) + xc_interface_close(xch); + if (xs_handle) + xs_daemon_close(xs_handle); +} + +/* Never shrink dom0 below 1 GiB */ +#define DOM0_FLOOR (1 << 30) +#define DOM0_FLOOR_PG ((DOM0_FLOOR) >> 12) + +/* Act if free memory is less than 92 MiB */ +#define THRESHOLD (92 << 20) +#define THRESHOLD_PG ((THRESHOLD) >> 12) + +#define BUFSZ 512 +void handle_low_mem(void) +{ + xc_dominfo_t dom0_info; + xc_physinfo_t info; + unsigned long long free_pages, dom0_pages, diff, dom0_target; + char data[BUFSZ], error[BUFSZ]; + + if (xc_physinfo(xch, &info) < 0) + { + perror("Getting physinfo failed"); + return; + } + + free_pages = (unsigned long long) info.free_pages; + printf("Available free pages: 0x%llx:%llux\n", + free_pages, free_pages); + + /* Don't do anything if we have more than the threshold free */ + if ( free_pages >= THRESHOLD_PG ) + return; + diff = THRESHOLD_PG - free_pages; + + if (xc_domain_getinfo(xch, 0, 1, &dom0_info) < 1) + { + perror("Failed to get dom0 info"); + return; + } + + dom0_pages = (unsigned long long) dom0_info.nr_pages; + printf("Dom0 pages: 0x%llx:%llu\n", dom0_pages, dom0_pages); + dom0_target = dom0_pages - diff; + if (dom0_target <= DOM0_FLOOR_PG) + return; + + printf("Shooting for dom0 target 0x%llx:%llu\n", + dom0_target, dom0_target); + + snprintf(data, BUFSZ, "%llu", dom0_target); + if (!xs_write(xs_handle, XBT_NULL, + "/local/domain/0/memory/target", data, strlen(data))) + { + snprintf(error, BUFSZ,"Failed to write target %s to xenstore", data); + perror(error); + } +} + +int main(int argc, char *argv[]) +{ + int rc; + + atexit(cleanup); + + xch = xc_interface_open(NULL, NULL, 0); + if (xch == NULL) + { + perror("Failed to open xc interface"); + return 1; + } + + xce_handle = xc_evtchn_open(NULL, 0); + if (xce_handle == NULL) + { + perror("Failed to open evtchn device"); + return 2; + } + + xs_handle = xs_daemon_open(); + if (xs_handle == NULL) + { + perror("Failed to open xenstore connection"); + return 3; + } + + if ((rc = xc_evtchn_bind_virq(xce_handle, VIRQ_ENOMEM)) == -1) + { + perror("Failed to bind to domain exception virq port"); + return 4; + } + + virq_port = rc; + + while(1) + { + evtchn_port_t port; + + if ((port = xc_evtchn_pending(xce_handle)) == -1) + { + perror("Failed to listen for pending event channel"); + return 5; + } + + if (port != virq_port) + { + char data[BUFSZ]; + snprintf(data, BUFSZ, "Wrong port, got %d expected %d", port, virq_port); + perror(data); + return 6; + } + + if (xc_evtchn_unmask(xce_handle, port) == -1) + { + perror("Failed to unmask port"); + return 7; + } + + printf("Got a virq kick, time to get work\n"); + handle_low_mem(); + } + + return 0; +} |