Hi Kazu, On Wed, Jan 17, 2024 at 4:11 PM HAGIO KAZUHITO(萩尾 一仁) <k-hagio-ab@xxxxxxx> wrote: > > On 2024/01/04 10:20, Tao Liu wrote: > > Previously, to find a module symbol and its offset by an arbitrary address, > > all symbols within the module will be iterated by address ascending order > > until the last symbol with a smaller address been noticed. > > > > However if the address is not within the module address range, e.g. > > the address is higher than the module's last symbol's address, then > > the module can be surely skipped, because its symbol iteration is > > unnecessary. This can speed up the kernel module symbols finding and improve > > the overall performance. > > > > Without the patch: > > $ time echo "bt 8993" | ~/crash-dev/crash vmcore vmlinux > > crash> bt 8993 > > PID: 8993 TASK: ffff927569cc2100 CPU: 2 COMMAND: "WriterPool0" > > #0 [ffff927569cd76f0] __schedule at ffffffffb3db78d8 > > #1 [ffff927569cd7758] schedule_preempt_disabled at ffffffffb3db8bf9 > > #2 [ffff927569cd7768] __mutex_lock_slowpath at ffffffffb3db6ca7 > > #3 [ffff927569cd77c0] mutex_lock at ffffffffb3db602f > > #4 [ffff927569cd77d8] ucache_retrieve at ffffffffc0cf4409 [secfs2] > > ...snip the stacktrace of the same module... > > #11 [ffff927569cd7ba0] cskal_path_vfs_getattr_nosec at ffffffffc05cae76 [falcon_kal] > > ...snip... > > #13 [ffff927569cd7c40] _ZdlPv at ffffffffc086e751 [falcon_lsm_serviceable] > > ...snip... > > #20 [ffff927569cd7ef8] unload_network_ops_symbols at ffffffffc06f11c0 [falcon_lsm_pinned_14713] > > #21 [ffff927569cd7f50] system_call_fastpath at ffffffffb3dc539a > > RIP: 00007f2b28ed4023 RSP: 00007f2a45fe7f80 RFLAGS: 00000206 > > RAX: 0000000000000012 RBX: 00007f2a68302e00 RCX: 00007f2a682546d8 > > RDX: 0000000000000826 RSI: 00007eb57ea6a000 RDI: 00000000000000e3 > > RBP: 00007eb57ea6a000 R8: 0000000000000826 R9: 00000002670bdfd2 > > R10: 00000002670bdfd2 R11: 0000000000000293 R12: 00000002670bdfd2 > > R13: 00007f29d501a480 R14: 0000000000000826 R15: 00000002670bdfd2 > > ORIG_RAX: 0000000000000012 CS: 0033 SS: 002b > > crash> > > real 7m14.826s > > user 7m12.502s > > sys 0m1.091s > > > > With the patch: > > $ time echo "bt 8993" | ~/crash-dev/crash vmcore vmlinux > > crash> bt 8993 > > PID: 8993 TASK: ffff927569cc2100 CPU: 2 COMMAND: "WriterPool0" > > #0 [ffff927569cd76f0] __schedule at ffffffffb3db78d8 > > #1 [ffff927569cd7758] schedule_preempt_disabled at ffffffffb3db8bf9 > > ...snip the same output... > > crash> > > real 0m8.827s > > user 0m7.896s > > sys 0m0.938s > > > > Signed-off-by: Tao Liu <ltao@xxxxxxxxxx> > > Nice, Looks good, and applied. > https://github.com/crash-utility/crash/commit/28891d112754 > Thanks for reviewing and applying the patch! Thanks, Tao Liu > Thanks, > Kazu > > > --- > > symbols.c | 5 ++++- > > 1 file changed, 4 insertions(+), 1 deletion(-) > > > > diff --git a/symbols.c b/symbols.c > > index 5d91991..88a3fd1 100644 > > --- a/symbols.c > > +++ b/symbols.c > > @@ -5561,7 +5561,7 @@ value_search_module_6_4(ulong value, ulong *offset) > > sp = lm->symtable[t]; > > sp_end = lm->symend[t]; > > > > - if (value < sp->value) > > + if (value < sp->value || value > sp_end->value) > > continue; > > > > splast = NULL; > > @@ -5646,6 +5646,9 @@ retry: > > if (sp->value > value) /* invalid -- between modules */ > > break; > > > > + if (sp_end->value < value) /* not within the module */ > > + continue; > > + > > /* > > * splast will contain the last module symbol encountered. > > * Note: "__insmod_"-type symbols will be set in splast only -- Crash-utility mailing list -- devel@xxxxxxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to devel-leave@xxxxxxxxxxxxxxxxxxxxxxxxxxx https://${domain_name}/admin/lists/devel.lists.crash-utility.osci.io/ Contribution Guidelines: https://github.com/crash-utility/crash/wiki
