| Message ID | 20220127205824.40626-1-dirty@apple.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] linux-user: Implement starttime field in self stat emulation | expand |
Le 27/01/2022 à 21:58, Cameron Esfahani a écrit : > Instead of always returning 0, return actual starttime. > > v2: Use clock_gettime() instead of scanning /proc/self/stat > > Signed-off-by: Cameron Esfahani <dirty@apple.com> > --- > linux-user/main.c | 11 +++++++++++ > linux-user/qemu.h | 3 +++ > linux-user/syscall.c | 3 +++ > 3 files changed, 17 insertions(+) > > diff --git a/linux-user/main.c b/linux-user/main.c > index 16def5215d..2e5e0e886b 100644 > --- a/linux-user/main.c > +++ b/linux-user/main.c > @@ -196,6 +196,17 @@ void init_task_state(TaskState *ts) > .ss_size = 0, > .ss_flags = TARGET_SS_DISABLE, > }; > + > + /* Capture task start time relative to system boot */ > + > + long long ticksPerSec = sysconf(_SC_CLK_TCK); I don't think we need a "long long" here. sysconf() returns "long". Use lower case with underscore https://qemu-project.gitlab.io/qemu/devel/style.html#variable-naming-conventions Put the declaration at the beginning of the function https://qemu-project.gitlab.io/qemu/devel/style.html#declarations > + struct timespec bt; > + > + if ((ticksPerSec > 0) && !clock_gettime(CLOCK_BOOTTIME, &bt)) { > + /* start_boottime is expressed in clock ticks */ > + ts->start_boottime = bt.tv_sec * ticksPerSec; You can cast ticksPerSec with uint64_t to have a 64bit result. > + ts->start_boottime += bt.tv_nsec * ticksPerSec / 1000000000L; Use NANOSECONDS_PER_SECOND > + } > } > > CPUArchState *cpu_copy(CPUArchState *env) > diff --git a/linux-user/qemu.h b/linux-user/qemu.h > index 7910ce59cc..86bc169e72 100644 > --- a/linux-user/qemu.h > +++ b/linux-user/qemu.h > @@ -158,6 +158,9 @@ typedef struct TaskState { > > /* This thread's sigaltstack, if it has one */ > struct target_sigaltstack sigaltstack_used; > + > + /* Start time of task after system boot in clock ticks */ > + unsigned long long start_boottime; Use uint64_t, like the kernel does for start_boottime. > } __attribute__((aligned(16))) TaskState; > > abi_long do_brk(abi_ulong new_brk); > diff --git a/linux-user/syscall.c b/linux-user/syscall.c > index 5950222a77..2f77dbdda7 100644 > --- a/linux-user/syscall.c > +++ b/linux-user/syscall.c > @@ -8107,6 +8107,9 @@ static int open_self_stat(void *cpu_env, int fd) > } else if (i == 3) { > /* ppid */ > g_string_printf(buf, FMT_pid " ", getppid()); > + } else if (i == 21) { > + /* starttime */ > + g_string_printf(buf, "%llu ", ts->start_boottime); with uint64_t, use "%PRIu64 ". > } else if (i == 27) { > /* stack bottom */ > g_string_printf(buf, TARGET_ABI_FMT_ld " ", ts->info->start_stack); Except these minor tweaks, it looks good. Thanks, Laurent
diff --git a/linux-user/main.c b/linux-user/main.c index 16def5215d..2e5e0e886b 100644 --- a/linux-user/main.c +++ b/linux-user/main.c @@ -196,6 +196,17 @@ void init_task_state(TaskState *ts) .ss_size = 0, .ss_flags = TARGET_SS_DISABLE, }; + + /* Capture task start time relative to system boot */ + + long long ticksPerSec = sysconf(_SC_CLK_TCK); + struct timespec bt; + + if ((ticksPerSec > 0) && !clock_gettime(CLOCK_BOOTTIME, &bt)) { + /* start_boottime is expressed in clock ticks */ + ts->start_boottime = bt.tv_sec * ticksPerSec; + ts->start_boottime += bt.tv_nsec * ticksPerSec / 1000000000L; + } } CPUArchState *cpu_copy(CPUArchState *env) diff --git a/linux-user/qemu.h b/linux-user/qemu.h index 7910ce59cc..86bc169e72 100644 --- a/linux-user/qemu.h +++ b/linux-user/qemu.h @@ -158,6 +158,9 @@ typedef struct TaskState { /* This thread's sigaltstack, if it has one */ struct target_sigaltstack sigaltstack_used; + + /* Start time of task after system boot in clock ticks */ + unsigned long long start_boottime; } __attribute__((aligned(16))) TaskState; abi_long do_brk(abi_ulong new_brk); diff --git a/linux-user/syscall.c b/linux-user/syscall.c index 5950222a77..2f77dbdda7 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -8107,6 +8107,9 @@ static int open_self_stat(void *cpu_env, int fd) } else if (i == 3) { /* ppid */ g_string_printf(buf, FMT_pid " ", getppid()); + } else if (i == 21) { + /* starttime */ + g_string_printf(buf, "%llu ", ts->start_boottime); } else if (i == 27) { /* stack bottom */ g_string_printf(buf, TARGET_ABI_FMT_ld " ", ts->info->start_stack);
Instead of always returning 0, return actual starttime. v2: Use clock_gettime() instead of scanning /proc/self/stat Signed-off-by: Cameron Esfahani <dirty@apple.com> --- linux-user/main.c | 11 +++++++++++ linux-user/qemu.h | 3 +++ linux-user/syscall.c | 3 +++ 3 files changed, 17 insertions(+)