* Re: Unkillable process in last git -- 100% reproducible [not found] <20060628142918.1b2c25c3@localhost> @ 2006-06-28 12:53 ` Paolo Ornati 2006-06-28 13:09 ` Paolo Ornati 0 siblings, 1 reply; 8+ messages in thread From: Paolo Ornati @ 2006-06-28 12:53 UTC (permalink / raw) To: Paolo Ornati; +Cc: Linux Kernel Mailing List On Wed, 28 Jun 2006 14:29:18 +0200 Paolo Ornati <ornati@fastwebnet.it> wrote: > [ 430.083347] localedef R running task 0 8577 8558 8578 (NOTLB) > [ 430.083352] gzip X ffff81001e612ee0 0 8578 8577 (L-TLB) > [ 430.083358] ffff81001395bef8 ffff81001fd1a310 0000000000000246 ffff81001e612ee0 > [ 430.083362] ffff81001e4c0080 ffff81001e612ee0 ffff81001e4c0258 0000000000000001 > [ 430.083366] 0000000000000046 0000000000000046 ffff81001395bf18 0000000000000010 > [ 430.083370] Call Trace: <ffffffff80227f6f>{do_exit+2378} <ffffffff802628e9>{vfs_write+288} > [ 430.083379] <ffffffff80228065>{sys_exit_group+0} <ffffffff80209806>{system_call+126} do_exit() -- kernel/exit.c 0xffffffff80227f66 <do_exit+2369>: mov %rax,0x18(%rbp) 0xffffffff80227f6a <do_exit+2373>: callq 0xffffffff8048b850 <schedule> 0xffffffff80227f6f <do_exit+2378>: ud2a 0xffffffff80227f71 <do_exit+2380>: pushq $0xffffffff804b7821 0xffffffff80227f76 <do_exit+2385>: retq $0x3ba 0xffffffff80227f79 <do_exit+2388>: jmp 0xffffffff80227f79 <do_exit+2388> -- Paolo Ornati Linux 2.6.17-ga39727f2-dirty on x86_64 ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: Unkillable process in last git -- 100% reproducible 2006-06-28 12:53 ` Unkillable process in last git -- 100% reproducible Paolo Ornati @ 2006-06-28 13:09 ` Paolo Ornati 2006-06-28 13:19 ` Paolo Ornati 0 siblings, 1 reply; 8+ messages in thread From: Paolo Ornati @ 2006-06-28 13:09 UTC (permalink / raw) To: Paolo Ornati; +Cc: Linux Kernel Mailing List On Wed, 28 Jun 2006 14:53:49 +0200 Paolo Ornati <ornati@fastwebnet.it> wrote: > > [ 430.083347] localedef R running task 0 8577 8558 8578 (NOTLB) > > [ 430.083352] gzip X ffff81001e612ee0 0 8578 8577 (L-TLB) > > [ 430.083358] ffff81001395bef8 ffff81001fd1a310 0000000000000246 ffff81001e612ee0 > > [ 430.083362] ffff81001e4c0080 ffff81001e612ee0 ffff81001e4c0258 0000000000000001 > > [ 430.083366] 0000000000000046 0000000000000046 ffff81001395bf18 0000000000000010 > > [ 430.083370] Call Trace: <ffffffff80227f6f>{do_exit+2378} <ffffffff802628e9>{vfs_write+288} > > [ 430.083379] <ffffffff80228065>{sys_exit_group+0} <ffffffff80209806>{system_call+126} > > do_exit() -- kernel/exit.c > > 0xffffffff80227f66 <do_exit+2369>: mov %rax,0x18(%rbp) > 0xffffffff80227f6a <do_exit+2373>: callq 0xffffffff8048b850 <schedule> > 0xffffffff80227f6f <do_exit+2378>: ud2a > 0xffffffff80227f71 <do_exit+2380>: pushq $0xffffffff804b7821 > 0xffffffff80227f76 <do_exit+2385>: retq $0x3ba > 0xffffffff80227f79 <do_exit+2388>: jmp 0xffffffff80227f79 <do_exit+2388> that is the end of the function: ... schedule(); BUG(); /* Avoid "noreturn function does return". */ for (;;) ; } So the questions are two: 1) why schedule() didn't work? 2) why the process is looping around "ud2a" (placed by BUG()) and presumibly throwing a lot of "invalid opcode" exceptions? -- Paolo Ornati Linux 2.6.17-ga39727f2-dirty on x86_64 ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: Unkillable process in last git -- 100% reproducible 2006-06-28 13:09 ` Paolo Ornati @ 2006-06-28 13:19 ` Paolo Ornati 2006-06-28 18:38 ` Unkillable process in last git -- Bisected Paolo Ornati 0 siblings, 1 reply; 8+ messages in thread From: Paolo Ornati @ 2006-06-28 13:19 UTC (permalink / raw) To: Paolo Ornati; +Cc: Linux Kernel Mailing List [-- Attachment #1: Type: text/plain, Size: 2280 bytes --] On Wed, 28 Jun 2006 15:09:43 +0200 Paolo Ornati <ornati@fastwebnet.it> wrote: > On Wed, 28 Jun 2006 14:53:49 +0200 > Paolo Ornati <ornati@fastwebnet.it> wrote: > > > > [ 430.083347] localedef R running task 0 8577 8558 8578 (NOTLB) > > > [ 430.083352] gzip X ffff81001e612ee0 0 8578 8577 (L-TLB) > > > [ 430.083358] ffff81001395bef8 ffff81001fd1a310 0000000000000246 ffff81001e612ee0 > > > [ 430.083362] ffff81001e4c0080 ffff81001e612ee0 ffff81001e4c0258 0000000000000001 > > > [ 430.083366] 0000000000000046 0000000000000046 ffff81001395bf18 0000000000000010 > > > [ 430.083370] Call Trace: <ffffffff80227f6f>{do_exit+2378} <ffffffff802628e9>{vfs_write+288} > > > [ 430.083379] <ffffffff80228065>{sys_exit_group+0} <ffffffff80209806>{system_call+126} > > > > do_exit() -- kernel/exit.c > > > > 0xffffffff80227f66 <do_exit+2369>: mov %rax,0x18(%rbp) > > 0xffffffff80227f6a <do_exit+2373>: callq 0xffffffff8048b850 <schedule> > > 0xffffffff80227f6f <do_exit+2378>: ud2a > > 0xffffffff80227f71 <do_exit+2380>: pushq $0xffffffff804b7821 > > 0xffffffff80227f76 <do_exit+2385>: retq $0x3ba > > 0xffffffff80227f79 <do_exit+2388>: jmp 0xffffffff80227f79 <do_exit+2388> > > > that is the end of the function: > > ... > schedule(); > BUG(); > /* Avoid "noreturn function does return". */ > for (;;) ; > } > > > So the questions are two: > > 1) why schedule() didn't work? > > 2) why the process is looping around "ud2a" (placed by BUG()) and > presumibly throwing a lot of "invalid opcode" exceptions? It seems that the first mail didn't hit LKML (maybe it was too big), here it is (stripped): ------------------------------------------------------------------------ Running "localedef" triggers an infinite loop in kernel mode (or something) --> localdef becomes unkillable. This is dmesg after pressing ALT+SysRQ+T three times: [CUT] KERNEL: -- Paolo Ornati Linux 2.6.17-ga39727f2-dirty on x86_64 ^^^^^^^ The -dirty is because of a fix to PS2 Keyboard auto-repeat, nothing else. ------------------------------------------------------------------------ Full config attached. [-- Attachment #2: config.gz --] [-- Type: application/x-gzip, Size: 8546 bytes --] ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: Unkillable process in last git -- Bisected 2006-06-28 13:19 ` Paolo Ornati @ 2006-06-28 18:38 ` Paolo Ornati 2006-06-28 19:06 ` Vladimir V. Saveliev 2006-06-29 5:20 ` Andrew Morton 0 siblings, 2 replies; 8+ messages in thread From: Paolo Ornati @ 2006-06-28 18:38 UTC (permalink / raw) To: Paolo Ornati Cc: Linux Kernel Mailing List, vs, Neil Brown, Martin Schwidefsky, stable On Wed, 28 Jun 2006 15:19:55 +0200 Paolo Ornati <ornati@fastwebnet.it> wrote: > > > > [ 430.083347] localedef R running task 0 8577 8558 8578 (NOTLB) > > > > [ 430.083352] gzip X ffff81001e612ee0 0 8578 8577 (L-TLB) > > > > [ 430.083358] ffff81001395bef8 ffff81001fd1a310 0000000000000246 ffff81001e612ee0 > > > > [ 430.083362] ffff81001e4c0080 ffff81001e612ee0 ffff81001e4c0258 0000000000000001 > > > > [ 430.083366] 0000000000000046 0000000000000046 ffff81001395bf18 0000000000000010 > > > > [ 430.083370] Call Trace: <ffffffff80227f6f>{do_exit+2378} <ffffffff802628e9>{vfs_write+288} > > > > [ 430.083379] <ffffffff80228065>{sys_exit_group+0} <ffffffff80209806>{system_call+126} > > > > > > do_exit() -- kernel/exit.c > > > > > > 0xffffffff80227f66 <do_exit+2369>: mov %rax,0x18(%rbp) > > > 0xffffffff80227f6a <do_exit+2373>: callq 0xffffffff8048b850 <schedule> > > > 0xffffffff80227f6f <do_exit+2378>: ud2a > > > 0xffffffff80227f71 <do_exit+2380>: pushq $0xffffffff804b7821 > > > 0xffffffff80227f76 <do_exit+2385>: retq $0x3ba > > > 0xffffffff80227f79 <do_exit+2388>: jmp 0xffffffff80227f79 <do_exit+2388> > > > > > > that is the end of the function: > > > > ... > > schedule(); > > BUG(); > > /* Avoid "noreturn function does return". */ > > for (;;) ; > > } > > > > > > So the questions are two: > > > > 1) why schedule() didn't work? > > > > 2) why the process is looping around "ud2a" (placed by BUG()) and > > presumibly throwing a lot of "invalid opcode" exceptions? > > It seems that the first mail didn't hit LKML (maybe it was too big), > here it is (stripped): > > ------------------------------------------------------------------------ > Running "localedef" triggers an infinite loop in kernel mode (or > something) --> localdef becomes unkillable. > > This is dmesg after pressing ALT+SysRQ+T three times: > > [CUT] > > KERNEL: > > -- > Paolo Ornati > Linux 2.6.17-ga39727f2-dirty on x86_64 > ^^^^^^^ > > The -dirty is because of a fix to PS2 Keyboard auto-repeat, nothing else. > ------------------------------------------------------------------------ Hi everybody, as you can see from the subject the problem is an unkillable process (localedef) that eats 100% CPU (the system is usable however). After a git-bisect session I've found that reverting the following commit fixes the problem. Any idea? commit 6527c2bdf1f833cc18e8f42bd97973d583e4aa83 Author: Vladimir V. Saveliev <vs@namesys.com> Date: Tue Jun 27 02:53:57 2006 -0700 [PATCH] generic_file_buffered_write(): deadlock on vectored write generic_file_buffered_write() prefaults in user pages in order to avoid deadlock on copying from the same page as write goes to. However, it looks like there is a problem when write is vectored: fault_in_pages_readable brings in current segment or its part (maxlen). OTOH, filemap_copy_from_user_iovec is called to copy number of bytes (bytes) which may exceed current segment, so filemap_copy_from_user_iovec switches to the next segment which is not brought in yet. Pagefault is generated. That causes the deadlock if pagefault is for the same page write goes to: page being written is locked and not uptodate, pagefault will deadlock trying to lock locked page. [akpm@osdl.org: somewhat rewritten] Cc: Neil Brown <neilb@suse.de> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org> diff --git a/mm/filemap.c b/mm/filemap.c index 9c7334b..d504d6e 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -2095,14 +2095,21 @@ generic_file_buffered_write(struct kiocb do { unsigned long index; unsigned long offset; - unsigned long maxlen; size_t copied; offset = (pos & (PAGE_CACHE_SIZE -1)); /* Within page */ index = pos >> PAGE_CACHE_SHIFT; bytes = PAGE_CACHE_SIZE - offset; - if (bytes > count) - bytes = count; + + /* Limit the size of the copy to the caller's write size */ + bytes = min(bytes, count); + + /* + * Limit the size of the copy to that of the current segment, + * because fault_in_pages_readable() doesn't know how to walk + * segments. + */ + bytes = min(bytes, cur_iov->iov_len - iov_base); /* * Bring in the user page that we will copy from _first_. @@ -2110,10 +2117,7 @@ generic_file_buffered_write(struct kiocb * same page as we're writing to, without it being marked * up-to-date. */ - maxlen = cur_iov->iov_len - iov_base; - if (maxlen > bytes) - maxlen = bytes; - fault_in_pages_readable(buf, maxlen); + fault_in_pages_readable(buf, bytes); page = __grab_cache_page(mapping,index,&cached_page,&lru_pvec); if (!page) { -- Paolo Ornati Linux 2.6.17.1 on x86_64 ^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: Unkillable process in last git -- Bisected 2006-06-28 18:38 ` Unkillable process in last git -- Bisected Paolo Ornati @ 2006-06-28 19:06 ` Vladimir V. Saveliev 2006-06-28 20:14 ` Paolo Ornati 2006-06-29 5:20 ` Andrew Morton 1 sibling, 1 reply; 8+ messages in thread From: Vladimir V. Saveliev @ 2006-06-28 19:06 UTC (permalink / raw) To: Paolo Ornati Cc: Linux Kernel Mailing List, Neil Brown, Martin Schwidefsky, stable Hello On Wed, 2006-06-28 at 20:38 +0200, Paolo Ornati wrote: > > Running "localedef" triggers an infinite loop in kernel mode (or > > something) --> localdef becomes unkillable. > > Can you, please, run localedef under strace -e set=open,write on a kernel having the below patch applied, so that we will see arguments of write which caused write to fall into endless loop. > commit 6527c2bdf1f833cc18e8f42bd97973d583e4aa83 > Author: Vladimir V. Saveliev <vs@namesys.com> > Date: Tue Jun 27 02:53:57 2006 -0700 > > [PATCH] generic_file_buffered_write(): deadlock on vectored write > > generic_file_buffered_write() prefaults in user pages in order to avoid > deadlock on copying from the same page as write goes to. > > However, it looks like there is a problem when write is vectored: > fault_in_pages_readable brings in current segment or its part (maxlen). > OTOH, filemap_copy_from_user_iovec is called to copy number of bytes > (bytes) which may exceed current segment, so filemap_copy_from_user_iovec > switches to the next segment which is not brought in yet. Pagefault is > generated. That causes the deadlock if pagefault is for the same page > write goes to: page being written is locked and not uptodate, pagefault > will deadlock trying to lock locked page. > > [akpm@osdl.org: somewhat rewritten] > Cc: Neil Brown <neilb@suse.de> > Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> > Cc: <stable@kernel.org> > Signed-off-by: Andrew Morton <akpm@osdl.org> > Signed-off-by: Linus Torvalds <torvalds@osdl.org> > > diff --git a/mm/filemap.c b/mm/filemap.c > index 9c7334b..d504d6e 100644 > --- a/mm/filemap.c > +++ b/mm/filemap.c > @@ -2095,14 +2095,21 @@ generic_file_buffered_write(struct kiocb > do { > unsigned long index; > unsigned long offset; > - unsigned long maxlen; > size_t copied; > > offset = (pos & (PAGE_CACHE_SIZE -1)); /* Within page */ > index = pos >> PAGE_CACHE_SHIFT; > bytes = PAGE_CACHE_SIZE - offset; > - if (bytes > count) > - bytes = count; > + > + /* Limit the size of the copy to the caller's write size */ > + bytes = min(bytes, count); > + > + /* > + * Limit the size of the copy to that of the current segment, > + * because fault_in_pages_readable() doesn't know how to walk > + * segments. > + */ > + bytes = min(bytes, cur_iov->iov_len - iov_base); > > /* > * Bring in the user page that we will copy from _first_. > @@ -2110,10 +2117,7 @@ generic_file_buffered_write(struct kiocb > * same page as we're writing to, without it being marked > * up-to-date. > */ > - maxlen = cur_iov->iov_len - iov_base; > - if (maxlen > bytes) > - maxlen = bytes; > - fault_in_pages_readable(buf, maxlen); > + fault_in_pages_readable(buf, bytes); > > page = __grab_cache_page(mapping,index,&cached_page,&lru_pvec); > if (!page) { > > > ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: Unkillable process in last git -- Bisected 2006-06-28 19:06 ` Vladimir V. Saveliev @ 2006-06-28 20:14 ` Paolo Ornati 0 siblings, 0 replies; 8+ messages in thread From: Paolo Ornati @ 2006-06-28 20:14 UTC (permalink / raw) To: Vladimir V. Saveliev Cc: Linux Kernel Mailing List, Neil Brown, Martin Schwidefsky, stable On Wed, 28 Jun 2006 23:06:17 +0400 "Vladimir V. Saveliev" <vs@namesys.com> wrote: > On Wed, 2006-06-28 at 20:38 +0200, Paolo Ornati wrote: > > > Running "localedef" triggers an infinite loop in kernel mode (or > > > something) --> localdef becomes unkillable. > > > > > Can you, please, run localedef under strace -e set=open,write on a > kernel having the below patch applied, so that we will see arguments of > write which caused write to fall into endless loop. The full strace is short enough, I think: $ strace localedef --no-archive -c -i en_US -f ISO-8859-1 -A /usr/share/locale/locale.alias en_US execve("/usr/bin/localedef", ["localedef", "--no-archive", "-c", "-i", "en_US", "-f", "ISO-8859-1", "-A", "/usr/share/locale/locale.alias", "en_US"], [/* 44 vars */]) = 0 uname({sys="Linux", node="tux", ...}) = 0 brk(0) = 0x549000 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x2b0f18098000 access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory) open("/etc/ld.so.cache", O_RDONLY) = 3 fstat(3, {st_mode=S_IFREG|0644, st_size=163137, ...}) = 0 mmap(NULL, 163137, PROT_READ, MAP_PRIVATE, 3, 0) = 0x2b0f18099000 close(3) = 0 open("/lib/tls/libc.so.6", O_RDONLY) = 3 read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\360\306"..., 640) = 640 lseek(3, 64, SEEK_SET) = 64 read(3, "\6\0\0\0\5\0\0\0@\0\0\0\0\0\0\0@\0\0\0\0\0\0\0@\0\0\0\0"..., 616) = 616 lseek(3, 680, SEEK_SET) = 680 read(3, "\4\0\0\0\20\0\0\0\1\0\0\0GNU\0\0\0\0\0\2\0\0\0\6\0\0\0"..., 32) = 32 fstat(3, {st_mode=S_IFREG|0755, st_size=1268224, ...}) = 0 lseek(3, 64, SEEK_SET) = 64 read(3, "\6\0\0\0\5\0\0\0@\0\0\0\0\0\0\0@\0\0\0\0\0\0\0@\0\0\0\0"..., 616) = 616 mmap(NULL, 2261000, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x2b0f1819a000 madvise(0x2b0f1819a000, 2261000, MADV_SEQUENTIAL|0x1) = 0 mprotect(0x2b0f182b9000, 1085448, PROT_NONE) = 0 mmap(0x2b0f183b8000, 24576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x11e000) = 0x2b0f183b8000 mmap(0x2b0f183be000, 16392, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x2b0f183be000 close(3) = 0 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x2b0f183c3000 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x2b0f183c4000 mprotect(0x2b0f183b8000, 12288, PROT_READ) = 0 mprotect(0x2b0f18198000, 4096, PROT_READ) = 0 arch_prctl(ARCH_SET_FS, 0x2b0f183c3ae0) = 0 munmap(0x2b0f18099000, 163137) = 0 open("/dev/urandom", O_RDONLY) = 3 read(3, "\363\300\254\335\34A\365\327", 8) = 8 close(3) = 0 brk(0) = 0x549000 brk(0x56a000) = 0x56a000 open("/usr/lib64/locale/locale-archive", O_RDONLY) = -1 ENOENT (No such file or directory) open("/usr/share/locale/locale.alias", O_RDONLY) = 3 fstat(3, {st_mode=S_IFREG|0644, st_size=2586, ...}) = 0 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x2b0f18099000 read(3, "# Locale name alias data base.\n#"..., 4096) = 2586 read(3, "", 4096) = 0 close(3) = 0 munmap(0x2b0f18099000, 4096) = 0 open("/usr/lib64/locale/en_US.utf8/LC_MESSAGES", O_RDONLY) = 3 fstat(3, {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0 close(3) = 0 open("/usr/lib64/locale/en_US.utf8/LC_MESSAGES/SYS_LC_MESSAGES", O_RDONLY) = 3 fstat(3, {st_mode=S_IFREG|0644, st_size=52, ...}) = 0 mmap(NULL, 52, PROT_READ, MAP_PRIVATE, 3, 0) = 0x2b0f18099000 close(3) = 0 open("/usr/lib64/gconv/gconv-modules.cache", O_RDONLY) = 3 fstat(3, {st_mode=S_IFREG|0644, st_size=21546, ...}) = 0 mmap(NULL, 21546, PROT_READ, MAP_SHARED, 3, 0) = 0x2b0f1809a000 close(3) = 0 open("/usr/lib64/locale/en_US.utf8/LC_CTYPE", O_RDONLY) = 3 fstat(3, {st_mode=S_IFREG|0644, st_size=208464, ...}) = 0 mmap(NULL, 208464, PROT_READ, MAP_PRIVATE, 3, 0) = 0x2b0f180a0000 close(3) = 0 access("/usr/lib64/locale/en_US", W_OK) = 0 open("ISO-8859-1", O_RDONLY) = -1 ENOENT (No such file or directory) open("/usr/share/i18n/charmaps/ISO-8859-1", O_RDONLY) = -1 ENOENT (No such file or directory) open("/usr/share/i18n/charmaps/ISO-8859-1.gz", O_RDONLY) = 3 fstat(3, {st_mode=S_IFREG|0644, st_size=3150, ...}) = 0 pipe([4, 5]) = 0 getrlimit(RLIMIT_NOFILE, {rlim_cur=1024, rlim_max=1024}) = 0 getrlimit(RLIMIT_NOFILE, {rlim_cur=1024, rlim_max=1024}) = 0 getrlimit(RLIMIT_NOFILE, {rlim_cur=1024, rlim_max=1024}) = 0 getrlimit(RLIMIT_NOFILE, {rlim_cur=1024, rlim_max=1024}) = 0 getrlimit(RLIMIT_NOFILE, {rlim_cur=1024, rlim_max=1024}) = 0 clone(child_stack=0, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD, child_tidptr=0x2b0f183c3b70) = 4258 close(5) = 0 close(3) = 0 fcntl(4, F_GETFL) = 0 (flags O_RDONLY) fstat(4, {st_mode=S_IFIFO|0600, st_size=0, ...}) = 0 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x2b0f180d3000 lseek(4, 0, SEEK_CUR) = -1 ESPIPE (Illegal seek) read(4, "<code_set_name> ISO-8859-1\n<comm"..., 4096) = 4096 read(4, " LATIN CAPITAL LETTER Z\n<U00"..., 4096) = 4096 read(4, " SUPERSCRIPT THREE\n<U00B4"..., 4096) = 4096 read(4, "L LETTER U WITH CIRCUMFLEX\n<U00F"..., 4096) = 337 read(4, "", 4096) = 0 close(4) = 0 munmap(0x2b0f180d3000, 4096) = 0 open("en_US", O_RDONLY) = -1 ENOENT (No such file or directory) open("/usr/share/i18n/locales/en_US", O_RDONLY) = 3 --- SIGCHLD (Child exited) @ 0 (0) --- fstat(3, {st_mode=S_IFREG|0644, st_size=5480, ...}) = 0 mmap(NULL, 5480, PROT_READ, MAP_SHARED, 3, 0) = 0x2b0f180d3000 lseek(3, 5480, SEEK_SET) = 5480 open("i18n", O_RDONLY) = -1 ENOENT (No such file or directory) open("/usr/share/i18n/locales/i18n", O_RDONLY) = 4 fstat(4, {st_mode=S_IFREG|0644, st_size=95199, ...}) = 0 mmap(NULL, 95199, PROT_READ, MAP_SHARED, 4, 0) = 0x2b0f180d5000 lseek(4, 95199, SEEK_SET) = 95199 brk(0x58b000) = 0x58b000 mmap(NULL, 262144, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x2b0f180ed000 mremap(0x2b0f180ed000, 262144, 524288, MREMAP_MAYMOVE) = 0x2b0f180ed000 brk(0x5ac000) = 0x5ac000 brk(0x5d4000) = 0x5d4000 mmap(NULL, 135168, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x2b0f1816d000 mmap(NULL, 135168, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x2b0f183c5000 mmap(NULL, 135168, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x2b0f183e6000 brk(0x5c7000) = 0x5c7000 mremap(0x2b0f1816d000, 135168, 266240, MREMAP_MAYMOVE) = 0x2b0f18407000 mremap(0x2b0f183c5000, 135168, 266240, MREMAP_MAYMOVE) = 0x2b0f18448000 mremap(0x2b0f183e6000, 135168, 266240, MREMAP_MAYMOVE) = 0x2b0f18489000 mremap(0x2b0f180ed000, 524288, 1048576, MREMAP_MAYMOVE) = 0x2b0f184ca000 mremap(0x2b0f18407000, 266240, 528384, MREMAP_MAYMOVE) = 0x2b0f180ed000 mremap(0x2b0f18448000, 266240, 528384, MREMAP_MAYMOVE) = 0x2b0f183c5000 mmap(NULL, 528384, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x2b0f185ca000 brk(0x5a7000) = 0x5a7000 mremap(0x2b0f18489000, 266240, 528384, MREMAP_MAYMOVE) = 0x2b0f1864b000 mremap(0x2b0f184ca000, 1048576, 3674112, MREMAP_MAYMOVE) = 0x2b0f186cc000 mremap(0x2b0f186cc000, 3674112, 7344128, MREMAP_MAYMOVE) = 0x2b0f186cc000 mremap(0x2b0f180ed000, 528384, 1052672, MREMAP_MAYMOVE) = 0x2b0f18446000 mremap(0x2b0f183c5000, 528384, 1052672, MREMAP_MAYMOVE) = 0x2b0f18dcd000 mremap(0x2b0f185ca000, 528384, 1052672, MREMAP_MAYMOVE) = 0x2b0f18ece000 mremap(0x2b0f1864b000, 528384, 1052672, MREMAP_MAYMOVE) = 0x2b0f18547000 brk(0x5c8000) = 0x5c8000 brk(0x5e9000) = 0x5e9000 brk(0x60a000) = 0x60a000 brk(0x62b000) = 0x62b000 brk(0x64c000) = 0x64c000 brk(0x66d000) = 0x66d000 fstat(4, {st_mode=S_IFREG|0644, st_size=95199, ...}) = 0 munmap(0x2b0f180d5000, 95199) = 0 close(4) = 0 open("iso14651_t1", O_RDONLY) = -1 ENOENT (No such file or directory) open("/usr/share/i18n/locales/iso14651_t1", O_RDONLY) = 4 fstat(4, {st_mode=S_IFREG|0644, st_size=47626, ...}) = 0 mmap(NULL, 47626, PROT_READ, MAP_SHARED, 4, 0) = 0x2b0f180d5000 lseek(4, 47626, SEEK_SET) = 47626 brk(0x68e000) = 0x68e000 brk(0x68d000) = 0x68d000 brk(0x6ae000) = 0x6ae000 brk(0x6cf000) = 0x6cf000 brk(0x6f0000) = 0x6f0000 brk(0x711000) = 0x711000 brk(0x73d000) = 0x73d000 fstat(4, {st_mode=S_IFREG|0644, st_size=47626, ...}) = 0 munmap(0x2b0f180d5000, 47626) = 0 close(4) = 0 fstat(3, {st_mode=S_IFREG|0644, st_size=5480, ...}) = 0 munmap(0x2b0f180d3000, 5480) = 0 close(3) = 0 open("translit_neutral", O_RDONLY) = -1 ENOENT (No such file or directory) open("/usr/share/i18n/locales/translit_neutral", O_RDONLY) = 3 fstat(3, {st_mode=S_IFREG|0644, st_size=7383, ...}) = 0 mmap(NULL, 7383, PROT_READ, MAP_SHARED, 3, 0) = 0x2b0f180d3000 lseek(3, 7383, SEEK_SET) = 7383 brk(0x75e000) = 0x75e000 fstat(3, {st_mode=S_IFREG|0644, st_size=7383, ...}) = 0 munmap(0x2b0f180d3000, 7383) = 0 close(3) = 0 open("translit_circle", O_RDONLY) = -1 ENOENT (No such file or directory) open("/usr/share/i18n/locales/translit_circle", O_RDONLY) = 3 fstat(3, {st_mode=S_IFREG|0644, st_size=14116, ...}) = 0 mmap(NULL, 14116, PROT_READ, MAP_SHARED, 3, 0) = 0x2b0f180d3000 lseek(3, 14116, SEEK_SET) = 14116 brk(0x77f000) = 0x77f000 fstat(3, {st_mode=S_IFREG|0644, st_size=14116, ...}) = 0 munmap(0x2b0f180d3000, 14116) = 0 close(3) = 0 open("translit_cjk_compat", O_RDONLY) = -1 ENOENT (No such file or directory) open("/usr/share/i18n/locales/translit_cjk_compat", O_RDONLY) = 3 fstat(3, {st_mode=S_IFREG|0644, st_size=59104, ...}) = 0 mmap(NULL, 59104, PROT_READ, MAP_SHARED, 3, 0) = 0x2b0f180d3000 lseek(3, 59104, SEEK_SET) = 59104 brk(0x7a0000) = 0x7a0000 brk(0x7c1000) = 0x7c1000 brk(0x7e2000) = 0x7e2000 brk(0x803000) = 0x803000 fstat(3, {st_mode=S_IFREG|0644, st_size=59104, ...}) = 0 munmap(0x2b0f180d3000, 59104) = 0 close(3) = 0 open("translit_compat", O_RDONLY) = -1 ENOENT (No such file or directory) open("/usr/share/i18n/locales/translit_compat", O_RDONLY) = 3 fstat(3, {st_mode=S_IFREG|0644, st_size=34361, ...}) = 0 mmap(NULL, 34361, PROT_READ, MAP_SHARED, 3, 0) = 0x2b0f180d3000 lseek(3, 34361, SEEK_SET) = 34361 brk(0x824000) = 0x824000 fstat(3, {st_mode=S_IFREG|0644, st_size=34361, ...}) = 0 munmap(0x2b0f180d3000, 34361) = 0 close(3) = 0 open("translit_font", O_RDONLY) = -1 ENOENT (No such file or directory) open("/usr/share/i18n/locales/translit_font", O_RDONLY) = 3 fstat(3, {st_mode=S_IFREG|0644, st_size=58986, ...}) = 0 mmap(NULL, 58986, PROT_READ, MAP_SHARED, 3, 0) = 0x2b0f180d3000 lseek(3, 58986, SEEK_SET) = 58986 brk(0x845000) = 0x845000 brk(0x866000) = 0x866000 brk(0x887000) = 0x887000 brk(0x8a8000) = 0x8a8000 fstat(3, {st_mode=S_IFREG|0644, st_size=58986, ...}) = 0 munmap(0x2b0f180d3000, 58986) = 0 close(3) = 0 open("translit_fraction", O_RDONLY) = -1 ENOENT (No such file or directory) open("/usr/share/i18n/locales/translit_fraction", O_RDONLY) = 3 fstat(3, {st_mode=S_IFREG|0644, st_size=2380, ...}) = 0 mmap(NULL, 2380, PROT_READ, MAP_SHARED, 3, 0) = 0x2b0f180d3000 lseek(3, 2380, SEEK_SET) = 2380 fstat(3, {st_mode=S_IFREG|0644, st_size=2380, ...}) = 0 munmap(0x2b0f180d3000, 2380) = 0 close(3) = 0 open("translit_narrow", O_RDONLY) = -1 ENOENT (No such file or directory) open("/usr/share/i18n/locales/translit_narrow", O_RDONLY) = 3 fstat(3, {st_mode=S_IFREG|0644, st_size=6210, ...}) = 0 mmap(NULL, 6210, PROT_READ, MAP_SHARED, 3, 0) = 0x2b0f180d3000 lseek(3, 6210, SEEK_SET) = 6210 brk(0x8c9000) = 0x8c9000 fstat(3, {st_mode=S_IFREG|0644, st_size=6210, ...}) = 0 munmap(0x2b0f180d3000, 6210) = 0 close(3) = 0 open("translit_small", O_RDONLY) = -1 ENOENT (No such file or directory) open("/usr/share/i18n/locales/translit_small", O_RDONLY) = 3 fstat(3, {st_mode=S_IFREG|0644, st_size=3088, ...}) = 0 mmap(NULL, 3088, PROT_READ, MAP_SHARED, 3, 0) = 0x2b0f180d3000 lseek(3, 3088, SEEK_SET) = 3088 fstat(3, {st_mode=S_IFREG|0644, st_size=3088, ...}) = 0 munmap(0x2b0f180d3000, 3088) = 0 close(3) = 0 open("translit_wide", O_RDONLY) = -1 ENOENT (No such file or directory) open("/usr/share/i18n/locales/translit_wide", O_RDONLY) = 3 fstat(3, {st_mode=S_IFREG|0644, st_size=5030, ...}) = 0 mmap(NULL, 5030, PROT_READ, MAP_SHARED, 3, 0) = 0x2b0f180d3000 lseek(3, 5030, SEEK_SET) = 5030 fstat(3, {st_mode=S_IFREG|0644, st_size=5030, ...}) = 0 munmap(0x2b0f180d3000, 5030) = 0 close(3) = 0 brk(0x8ea000) = 0x8ea000 brk(0x910000) = 0x910000 unlink("/usr/lib64/locale/en_US/LC_CTYPE") = 0 creat("/usr/lib64/locale/en_US/LC_CTYPE", 0666) = 3 writev(3, [{"\25\21\3 X\0\0\0", 8}, {"h\1\0\0h\4\0\0h\n\0\0h\n\0\0h\20\0\0h\20\0\0h\24\0\0h\24"..., 352}, {"\2\0\2\0\2\0\2\0\2\0\2\0\2\0\2\0\2\0\2\0\2\0\2\0\2\0\2"..., 768}, {"\200\0\0\0\201\0\0\0\202\0\0\0\203\0\0\0\204\0\0\0\205"..., 1536}, {NULL, 0}, {"\200\0\0\0\201\0\0\0\202\0\0\0\203\0\0\0\204\0\0\0\205"..., 1536}, {NULL, 0}, {"\0\0\2\0\0\0\2\0\0\0\2\0\0\0\2\0\0\0\2\0\0\0\2\0\0\0\2"..., 1024}, {NULL, 0}, {NULL, 0}, {NULL, 0}, {NULL, 0}, {"upper\0", 6}, {"lower\0", 6}, {"alpha\0", 6}, {"digit\0", 6}, {"xdigit\0", 7}, {"space\0", 6}, {"print\0", 6}, {"graph\0", 6}, {"blank\0", 6}, {"cntrl\0", 6}, {"punct\0", 6}, {"alnum\0", 6}, {"combining\0", 10}, {"combining_level3\0", 17}, {"\0\0\0\0", 4}, {"toupper\0", 8}, {"tolower\0", 8}, {"totitle\0", 8}, {"\0\0\0\0", 4}, {"\20\0\0\0\1\0\0\0\7\0\0\0\377\1\0\0\177\0\0\0\30\0\0\0"..., 2328}, ...], 125 -- Paolo Ornati Linux 2.6.17.1 on x86_64 ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: Unkillable process in last git -- Bisected 2006-06-28 18:38 ` Unkillable process in last git -- Bisected Paolo Ornati 2006-06-28 19:06 ` Vladimir V. Saveliev @ 2006-06-29 5:20 ` Andrew Morton 2006-06-29 6:23 ` Paolo Ornati 1 sibling, 1 reply; 8+ messages in thread From: Andrew Morton @ 2006-06-29 5:20 UTC (permalink / raw) To: Paolo Ornati; +Cc: ornati, linux-kernel, vs, neilb, schwidefsky, stable On Wed, 28 Jun 2006 20:38:25 +0200 Paolo Ornati <ornati@fastwebnet.it> wrote: > After a git-bisect session I've found that reverting the following > commit fixes the problem. > > Any idea? > > > commit 6527c2bdf1f833cc18e8f42bd97973d583e4aa83 > Author: Vladimir V. Saveliev <vs@namesys.com> > Date: Tue Jun 27 02:53:57 2006 -0700 > > [PATCH] generic_file_buffered_write(): deadlock on vectored write From: Andrew Morton <akpm@osdl.org> The recent generic_file_write() deadlock fix caused generic_file_buffered_write() to loop inifinitely when presented with a zero-length iovec segment. Fix. Note that this fix deliberately avoids calling ->prepare_write(), ->commit_write() etc with a zero-length write. This is because I don't trust all filesystems to get that right. This is a cautious approach, for 2.6.17.x. For 2.6.18 we should just go ahead and call ->prepare_write() and ->commit_write() with the zero length and fix any broken filesystems. So I'll make that change once this code is stabilised and backported into 2.6.17.x. The reason for preferring to call ->prepare_write() and ->commit_write() with the zero-length segment: a zero-length segment _should_ be sufficiently uncommon that this is the correct way of handling it. We don't want to optimise for poorly-written userspace at the expense of well-written userspace. Cc: "Vladimir V. Saveliev" <vs@namesys.com> Cc: Neil Brown <neilb@suse.de> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Chris Wright <chrisw@sous-sol.org> Cc: Greg KH <greg@kroah.com> Cc: <stable@kernel.org> Cc: walt <wa1ter@myrealbox.com> Signed-off-by: Andrew Morton <akpm@osdl.org> --- mm/filemap.c | 9 ++++++++- mm/filemap.h | 4 ++-- 2 files changed, 10 insertions(+), 3 deletions(-) diff -puN mm/filemap.c~generic_file_buffered_write-handle-zero-length-iovec-segments-stable mm/filemap.c --- a/mm/filemap.c~generic_file_buffered_write-handle-zero-length-iovec-segments-stable +++ a/mm/filemap.c @@ -2125,6 +2125,12 @@ generic_file_buffered_write(struct kiocb break; } + if (unlikely(bytes == 0)) { + status = 0; + copied = 0; + goto zero_length_segment; + } + status = a_ops->prepare_write(file, page, offset, offset+bytes); if (unlikely(status)) { loff_t isize = i_size_read(inode); @@ -2154,7 +2160,8 @@ generic_file_buffered_write(struct kiocb page_cache_release(page); continue; } - if (likely(copied > 0)) { +zero_length_segment: + if (likely(copied >= 0)) { if (!status) status = copied; diff -puN mm/filemap.h~generic_file_buffered_write-handle-zero-length-iovec-segments-stable mm/filemap.h --- a/mm/filemap.h~generic_file_buffered_write-handle-zero-length-iovec-segments-stable +++ a/mm/filemap.h @@ -88,7 +88,7 @@ filemap_set_next_iovec(const struct iove const struct iovec *iov = *iovp; size_t base = *basep; - while (bytes) { + do { int copy = min(bytes, iov->iov_len - base); bytes -= copy; @@ -97,7 +97,7 @@ filemap_set_next_iovec(const struct iove iov++; base = 0; } - } + } while (bytes); *iovp = iov; *basep = base; } _ ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: Unkillable process in last git -- Bisected 2006-06-29 5:20 ` Andrew Morton @ 2006-06-29 6:23 ` Paolo Ornati 0 siblings, 0 replies; 8+ messages in thread From: Paolo Ornati @ 2006-06-29 6:23 UTC (permalink / raw) To: Andrew Morton; +Cc: linux-kernel, vs, neilb, schwidefsky, stable On Wed, 28 Jun 2006 22:20:36 -0700 Andrew Morton <akpm@osdl.org> wrote: > From: Andrew Morton <akpm@osdl.org> > > The recent generic_file_write() deadlock fix caused > generic_file_buffered_write() to loop inifinitely when presented with a > zero-length iovec segment. Fix. It works for me :) -- Paolo Ornati Linux 2.6.17.1 on x86_64 ^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2006-06-29 6:23 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz follow: Atom feed
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2006-06-28 12:53 ` Unkillable process in last git -- 100% reproducible Paolo Ornati
2006-06-28 13:09 ` Paolo Ornati
2006-06-28 13:19 ` Paolo Ornati
2006-06-28 18:38 ` Unkillable process in last git -- Bisected Paolo Ornati
2006-06-28 19:06 ` Vladimir V. Saveliev
2006-06-28 20:14 ` Paolo Ornati
2006-06-29 5:20 ` Andrew Morton
2006-06-29 6:23 ` Paolo Ornati
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