From b8bf338dbd4047138fdf2054a44e3efae328ef5d Mon Sep 17 00:00:00 2001 From: cee1 Date: Fri, 18 Mar 2011 10:03:41 +0800 Subject: [PATCH] Detect page size runtime. Some architectures support multiple machine types with diffenent page sizes, and some machine types even support multiple page sizes themselves. --- src/macro.h | 11 +++-------- src/readahead-collect.c | 9 ++++++++- src/readahead-common.c | 11 +++++++++++ src/readahead-common.h | 1 + src/readahead-replay.c | 8 +++++++- 5 files changed, 30 insertions(+), 10 deletions(-) diff --git a/src/macro.h b/src/macro.h index 996b7c2..e7a4d2c 100644 --- a/src/macro.h +++ b/src/macro.h @@ -27,8 +27,6 @@ #include #include -#define PAGE_SIZE 4096 - #define _printf_attr_(a,b) __attribute__ ((format (printf, a, b))) #define _sentinel_ __attribute__ ((sentinel)) #define _noreturn_ __attribute__((noreturn)) @@ -51,12 +49,9 @@ #define STRINGIFY(x) XSTRINGIFY(x) /* Rounds up */ -static inline size_t ALIGN(size_t l) { - return ((l + sizeof(void*) - 1) & ~(sizeof(void*) - 1)); -} - -static inline size_t PAGE_ALIGN(size_t l) { - return ((l + PAGE_SIZE - 1) & ~(PAGE_SIZE -1)); +#define ALIGN(l) ALIGN_TO((l), sizeof(void*)) +static inline size_t ALIGN_TO(size_t l, size_t ali) { + return ((l + ali - 1) & ~(ali - 1)); } #define ELEMENTSOF(x) (sizeof(x)/sizeof((x)[0])) diff --git a/src/readahead-collect.c b/src/readahead-collect.c index ca82271..67f3c4b 100644 --- a/src/readahead-collect.c +++ b/src/readahead-collect.c @@ -64,6 +64,10 @@ static unsigned arg_files_max = 16*1024; static off_t arg_file_size_max = READAHEAD_FILE_SIZE_MAX; static usec_t arg_timeout = 2*USEC_PER_MINUTE; +static size_t page_size; +#undef PAGE_ALIGN +#define PAGE_ALIGN(l) ALIGN_TO((l), page_size) + static ReadaheadShared *shared = NULL; /* Avoid collisions with the NULL pointer */ @@ -119,9 +123,10 @@ static int pack_file(FILE *pack, const char *fn, bool on_btrfs) { goto finish; } - pages = l / PAGE_SIZE; + pages = l / page_size; vec = alloca(pages); + memset(vec, 0, pages); if (mincore(start, l, vec) < 0) { log_warning("mincore(%s) failed: %m", fn); r = -errno; @@ -649,6 +654,8 @@ int main(int argc, char *argv[]) { return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS; root = optind < argc ? argv[optind] : "/"; + page_size = get_pagesize(); + log_debug("Detected page size is %d.", page_size); if (fs_on_read_only(root) > 0) { log_info("Disabling readahead collector due to read-only media."); diff --git a/src/readahead-common.c b/src/readahead-common.c index 990ffd4..ae6c1e5 100644 --- a/src/readahead-common.c +++ b/src/readahead-common.c @@ -33,6 +33,17 @@ #include "readahead-common.h" #include "util.h" +size_t get_pagesize() +{ + long pgsz = sysconf(_SC_PAGESIZE); + if (pgsz <= 0) { + log_warning("sysconf(_SC_PAGESIZE) failed, assume page size is 4096: %m"); + pgsz = 4096; + } + + return (size_t) pgsz; +} + int file_verify(int fd, const char *fn, off_t file_size_max, struct stat *st) { assert(fd >= 0); assert(fn); diff --git a/src/readahead-common.h b/src/readahead-common.h index 167df31..022a7fa 100644 --- a/src/readahead-common.h +++ b/src/readahead-common.h @@ -29,6 +29,7 @@ #define READAHEAD_FILE_SIZE_MAX (128*1024*1024) +size_t get_pagesize(); int file_verify(int fd, const char *fn, off_t file_size_max, struct stat *st); int fs_on_ssd(const char *p); diff --git a/src/readahead-replay.c b/src/readahead-replay.c index d2de7ef..8bc241f 100644 --- a/src/readahead-replay.c +++ b/src/readahead-replay.c @@ -44,6 +44,10 @@ static off_t arg_file_size_max = READAHEAD_FILE_SIZE_MAX; +static size_t page_size; +#undef PAGE_ALIGN +#define PAGE_ALIGN(l) ALIGN_TO((l), page_size) + static ReadaheadShared *shared = NULL; static int unpack_file(FILE *pack) { @@ -94,7 +98,7 @@ static int unpack_file(FILE *pack) { any = true; if (fd >= 0) - if (posix_fadvise(fd, b * PAGE_SIZE, (c - b) * PAGE_SIZE, POSIX_FADV_WILLNEED) < 0) { + if (posix_fadvise(fd, b * page_size, (c - b) * page_size, POSIX_FADV_WILLNEED) < 0) { log_warning("posix_fadvise() failed: %m"); goto finish; } @@ -343,6 +347,8 @@ int main(int argc, char*argv[]) { return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS; root = optind < argc ? argv[optind] : "/"; + page_size = get_pagesize(); + log_debug("Detected page size is %d.", page_size); if (!enough_ram()) { log_info("Disabling readahead replay due to low memory."); -- 1.7.4.1