[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen-unstable] xl: free memory before building a domain
# HG changeset patch # User Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx> # Date 1285174956 -3600 # Node ID d4a30bee570198e7dfce0f43b20de52fb4f0574b # Parent afe7d12da9418910400771e3c3bb4e14843fdb56 xl: free memory before building a domain Free the needed amount of memory before proceeding with the domain build. Use a filelock to prevent other xl instances from conflicting during this operation. Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx> Signed-off-by: Ian Jackson <ian.jackson@xxxxxxxxxxxxx> --- tools/examples/xl.conf | 3 + tools/libxl/xl.c | 12 ++++ tools/libxl/xl.h | 1 tools/libxl/xl_cmdimpl.c | 116 +++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 132 insertions(+) diff -r afe7d12da941 -r d4a30bee5701 tools/examples/xl.conf --- a/tools/examples/xl.conf Wed Sep 22 17:55:38 2010 +0100 +++ b/tools/examples/xl.conf Wed Sep 22 18:02:36 2010 +0100 @@ -3,3 +3,6 @@ # automatically balloon down dom0 when xen doesn't have enough free # memory to create a domain #autoballon=1 + +# full path of the lockfile used by xl during domain creation +#lockfile="/var/lock/xl" diff -r afe7d12da941 -r d4a30bee5701 tools/libxl/xl.c --- a/tools/libxl/xl.c Wed Sep 22 17:55:38 2010 +0100 +++ b/tools/libxl/xl.c Wed Sep 22 18:02:36 2010 +0100 @@ -34,6 +34,7 @@ xentoollog_logger_stdiostream *logger; int autoballoon = 1; +char *lockfile; static xentoollog_level minmsglevel = XTL_PROGRESS; @@ -44,6 +45,7 @@ static void parse_global_config(const ch long l; XLU_Config *config; int e; + const char *buf; config = xlu_cfg_init(stderr, configfile); if (!config) { @@ -59,6 +61,16 @@ static void parse_global_config(const ch if (!xlu_cfg_get_long (config, "autoballoon", &l)) autoballoon = l; + + if (!xlu_cfg_get_string (config, "lockfile", &buf)) + lockfile = strdup(buf); + else { + e = asprintf(&lockfile, "%s/xl", (char *)libxl_lock_dir_path()); + if (e < 0) { + fprintf(stderr, "asprintf memory allocation failed\n"); + exit(1); + } + } xlu_cfg_destroy(config); } diff -r afe7d12da941 -r d4a30bee5701 tools/libxl/xl.h --- a/tools/libxl/xl.h Wed Sep 22 17:55:38 2010 +0100 +++ b/tools/libxl/xl.h Wed Sep 22 18:02:36 2010 +0100 @@ -92,5 +92,6 @@ extern xentoollog_logger_stdiostream *lo /* global options */ extern int autoballoon; +extern char *lockfile; #endif /* XL_H */ diff -r afe7d12da941 -r d4a30bee5701 tools/libxl/xl_cmdimpl.c --- a/tools/libxl/xl_cmdimpl.c Wed Sep 22 17:55:38 2010 +0100 +++ b/tools/libxl/xl_cmdimpl.c Wed Sep 22 18:02:36 2010 +0100 @@ -68,6 +68,7 @@ libxl_ctx ctx; /* when we operate on a domain, it is this one: */ static uint32_t domid; static const char *common_domname; +static int fd_lock = -1; static const char savefileheader_magic[32]= @@ -232,6 +233,65 @@ static void find_domain(const char *p) exit(2); } common_domname = was_name ? p : libxl_domid_to_name(&ctx, domid); +} + +static int acquire_lock(void) +{ + int rc; + struct flock fl; + + /* lock already acquired */ + if (fd_lock >= 0) + return ERROR_INVAL; + + fl.l_type = F_WRLCK; + fl.l_whence = SEEK_SET; + fl.l_start = 0; + fl.l_len = 0; + fd_lock = open(lockfile, O_WRONLY|O_CREAT, S_IWUSR); + if (fd_lock < 0) { + fprintf(stderr, "cannot open the lockfile %s errno=%d\n", lockfile, errno); + return ERROR_FAIL; + } +get_lock: + rc = fcntl(fd_lock, F_SETLKW, &fl); + if (rc < 0 && errno == EINTR) + goto get_lock; + if (rc < 0) { + fprintf(stderr, "cannot acquire lock %s errno=%d\n", lockfile, errno); + rc = ERROR_FAIL; + } else + rc = 0; + return rc; +} + +static int release_lock(void) +{ + int rc; + struct flock fl; + + /* lock not acquired */ + if (fd_lock < 0) + return ERROR_INVAL; + +release_lock: + fl.l_type = F_UNLCK; + fl.l_whence = SEEK_SET; + fl.l_start = 0; + fl.l_len = 0; + + rc = fcntl(fd_lock, F_SETLKW, &fl); + if (rc < 0 && errno == EINTR) + goto release_lock; + if (rc < 0) { + fprintf(stderr, "cannot release lock %s, errno=%d\n", lockfile, errno); + rc = ERROR_FAIL; + } else + rc = 0; + close(fd_lock); + fd_lock = -1; + + return rc; } #define LOG(_f, _a...) dolog(__FILE__, __LINE__, __func__, _f "\n", ##_a) @@ -1213,6 +1273,48 @@ struct domain_create { char **migration_domname_r; /* from malloc */ }; +static int freemem(libxl_domain_build_info *b_info, libxl_device_model_info *dm_info) +{ + int rc, retries = 3; + uint32_t need_memkb, free_memkb; + + if (!autoballoon) + return 0; + + rc = libxl_domain_need_memory(&ctx, b_info, dm_info, &need_memkb); + if (rc < 0) + return rc; + + do { + rc = libxl_get_free_memory(&ctx, &free_memkb); + if (rc < 0) + return rc; + + if (free_memkb >= need_memkb) + return 0; + + rc = libxl_set_memory_target(&ctx, 0, free_memkb - need_memkb, 1, 0); + if (rc < 0) + return rc; + + rc = libxl_wait_for_free_memory(&ctx, domid, need_memkb, 10); + if (!rc) + return 0; + else if (rc != ERROR_NOMEM) + return rc; + + /* the memory target has been reached but the free memory is still + * not enough: loop over again */ + rc = libxl_wait_for_memory_target(&ctx, 0, 1); + if (rc < 0) + return rc; + + retries--; + } while (retries > 0); + + return ERROR_NOMEM; +} + static int create_domain(struct domain_create *dom_info) { struct domain_config d_config; @@ -1372,6 +1474,17 @@ start: start: domid = 0; + rc = acquire_lock(); + if (rc < 0) + goto error_out; + + ret = freemem(&d_config.b_info, &dm_info); + if (ret < 0) { + fprintf(stderr, "failed to free memory for the domain\n"); + ret = ERROR_FAIL; + goto error_out; + } + ret = libxl_domain_make(&ctx, &d_config.c_info, &domid); if (ret) { fprintf(stderr, "cannot make domain: %d\n", ret); @@ -1481,6 +1594,8 @@ start: if (child_console_pid < 0) goto error_out; } + + release_lock(); if (!paused) libxl_domain_unpause(&ctx, domid); @@ -1619,6 +1734,7 @@ start: } error_out: + release_lock(); if (domid) libxl_domain_destroy(&ctx, domid, 0); _______________________________________________ Xen-changelog mailing list Xen-changelog@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-changelog
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