Resubmit r295469 [PGO] Suspend SIGKILL for PR_SET_PDEATHSIG in profile-write

And also r295364 [PGO] remove unintended debug trace. NFC
I removed the test case: it's hard to write synchronized test b/w processes
in this framework. I will revisit the test-case later.

llvm-svn: 298113
This commit is contained in:
Rong Xu 2017-03-17 18:41:33 +00:00
parent 848582181e
commit cf1f6fb1b2
3 changed files with 40 additions and 0 deletions

View File

@ -530,6 +530,7 @@ int __llvm_profile_write_file(void) {
int rc, Length; int rc, Length;
const char *Filename; const char *Filename;
char *FilenameBuf; char *FilenameBuf;
int PDeathSig = 0;
if (lprofProfileDumped()) { if (lprofProfileDumped()) {
PROF_NOTE("Profile data not written to file: %s.\n", PROF_NOTE("Profile data not written to file: %s.\n",
@ -556,10 +557,18 @@ int __llvm_profile_write_file(void) {
return -1; return -1;
} }
// Temporarily suspend getting SIGKILL when the parent exits.
PDeathSig = lprofSuspendSigKill();
/* Write profile data to the file. */ /* Write profile data to the file. */
rc = writeFile(Filename); rc = writeFile(Filename);
if (rc) if (rc)
PROF_ERR("Failed to write file \"%s\": %s\n", Filename, strerror(errno)); PROF_ERR("Failed to write file \"%s\": %s\n", Filename, strerror(errno));
// Restore SIGKILL.
if (PDeathSig == 1)
lprofRestoreSigKill();
return rc; return rc;
} }

View File

@ -29,6 +29,11 @@
#include <stdlib.h> #include <stdlib.h>
#include <string.h> #include <string.h>
#if defined(__linux__)
#include <signal.h>
#include <sys/prctl.h>
#endif
COMPILER_RT_VISIBILITY COMPILER_RT_VISIBILITY
void __llvm_profile_recursive_mkdir(char *path) { void __llvm_profile_recursive_mkdir(char *path) {
int i; int i;
@ -219,3 +224,21 @@ COMPILER_RT_VISIBILITY const char *lprofFindLastDirSeparator(const char *Path) {
#endif #endif
return Sep; return Sep;
} }
COMPILER_RT_VISIBILITY int lprofSuspendSigKill() {
#if defined(__linux__)
int PDeachSig = 0;
/* Temporarily suspend getting SIGKILL upon exit of the parent process. */
if (prctl(PR_GET_PDEATHSIG, &PDeachSig) == 0 && PDeachSig == SIGKILL)
prctl(PR_SET_PDEATHSIG, 0);
return (PDeachSig == SIGKILL);
#else
return 0;
#endif
}
COMPILER_RT_VISIBILITY void lprofRestoreSigKill() {
#if defined(__linux__)
prctl(PR_SET_PDEATHSIG, SIGKILL);
#endif
}

View File

@ -51,4 +51,12 @@ int lprofGetHostName(char *Name, int Len);
unsigned lprofBoolCmpXchg(void **Ptr, void *OldV, void *NewV); unsigned lprofBoolCmpXchg(void **Ptr, void *OldV, void *NewV);
void *lprofPtrFetchAdd(void **Mem, long ByteIncr); void *lprofPtrFetchAdd(void **Mem, long ByteIncr);
/* Temporarily suspend SIGKILL. Return value of 1 means a restore is needed.
* Other return values mean no restore is needed.
*/
int lprofSuspendSigKill();
/* Restore previously suspended SIGKILL. */
void lprofRestoreSigKill();
#endif /* PROFILE_INSTRPROFILINGUTIL_H */ #endif /* PROFILE_INSTRPROFILINGUTIL_H */