Eric Lee / smarc-ti-linux-kernel

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Commit b0fafc11115938a3215723f37e8e9cc6a94b05b0

Authored by Oleg Nesterov
Committed by Linus Torvalds
1 parent 0f4a0d53f2
Exists in ti-lsk-linux-4.1.y and in 10 other branches dlt-processor-sdk-linux-03.00.00.04, processor-sdk-linux-02.00.01, smarc-ti-lsk-linux-4.1.y, smarct3x-processor-sdk-04.01.00.06, smarct3x-processor-sdk-linux-02.00.01, smarct3x-processor-sdk-linux-03.00.00.04, smarct4x-800-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-04.01.00.06, smarct4x-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-linux-03.00.00.04

proc: task_state: move the main seq_printf() outside of rcu_read_lock() 

task_state() does seq_printf() under rcu_read_lock(), but this is only
needed for task_tgid_nr_ns() and task_numa_group_id().  We can calculate
tgid/ngid and drop rcu lock.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Aaron Tomlin <atomlin@redhat.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>,
Cc: Sterling Alexander <stalexan@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Roland McGrath <roland@hack.frob.com>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Showing 1 changed file with 6 additions and 6 deletions Side-by-side Diff

... ... @@ -158,7 +158,7 @@
158 158 struct group_info *group_info;
159 159 int g;
160 160 const struct cred *cred;
161   - pid_t ppid, tpid;
  161 + pid_t ppid, tpid, tgid, ngid;
162 162 unsigned int max_fds = 0;
163 163  
164 164 rcu_read_lock();
165 165  
... ... @@ -170,12 +170,16 @@
170 170 if (tracer)
171 171 tpid = task_pid_nr_ns(tracer, ns);
172 172 }
  173 +
  174 + tgid = task_tgid_nr_ns(p, ns);
  175 + ngid = task_numa_group_id(p);
173 176 cred = get_task_cred(p);
174 177  
175 178 task_lock(p);
176 179 if (p->files)
177 180 max_fds = files_fdtable(p->files)->max_fds;
178 181 task_unlock(p);
  182 + rcu_read_unlock();
179 183  
180 184 seq_printf(m,
181 185 "State:\t%s\n"
... ... @@ -188,10 +192,7 @@
188 192 "Gid:\t%d\t%d\t%d\t%d\n"
189 193 "FDSize:\t%d\nGroups:\t",
190 194 get_task_state(p),
191   - task_tgid_nr_ns(p, ns),
192   - task_numa_group_id(p),
193   - pid_nr_ns(pid, ns),
194   - ppid, tpid,
  195 + tgid, ngid, pid_nr_ns(pid, ns), ppid, tpid,
195 196 from_kuid_munged(user_ns, cred->uid),
196 197 from_kuid_munged(user_ns, cred->euid),
197 198 from_kuid_munged(user_ns, cred->suid),
... ... @@ -201,7 +202,6 @@
201 202 from_kgid_munged(user_ns, cred->sgid),
202 203 from_kgid_munged(user_ns, cred->fsgid),
203 204 max_fds);
204   - rcu_read_unlock();
205 205  
206 206 group_info = cred->group_info;
207 207 for (g = 0; g < group_info->ngroups; g++)