diff options
Diffstat (limited to 'Documentation/trace')
| -rw-r--r-- | Documentation/trace/ftrace-design.txt | 153 | ||||
| -rw-r--r-- | Documentation/trace/kmemtrace.txt | 126 | ||||
| -rw-r--r-- | Documentation/trace/kprobetrace.txt | 2 | ||||
| -rw-r--r-- | Documentation/trace/postprocess/trace-vmscan-postprocess.pl | 686 |
4 files changed, 835 insertions, 132 deletions
diff --git a/Documentation/trace/ftrace-design.txt b/Documentation/trace/ftrace-design.txt index f1f81af..dc52bd4 100644 --- a/Documentation/trace/ftrace-design.txt +++ b/Documentation/trace/ftrace-design.txt @@ -13,6 +13,9 @@ Note that this focuses on architecture implementation details only. If you want more explanation of a feature in terms of common code, review the common ftrace.txt file. +Ideally, everyone who wishes to retain performance while supporting tracing in +their kernel should make it all the way to dynamic ftrace support. + Prerequisites ------------- @@ -215,7 +218,7 @@ An arch may pass in a unique value (frame pointer) to both the entering and exiting of a function. On exit, the value is compared and if it does not match, then it will panic the kernel. This is largely a sanity check for bad code generation with gcc. If gcc for your port sanely updates the frame -pointer under different opitmization levels, then ignore this option. +pointer under different optimization levels, then ignore this option. However, adding support for it isn't terribly difficult. In your assembly code that calls prepare_ftrace_return(), pass the frame pointer as the 3rd argument. @@ -234,7 +237,7 @@ If you can't trace NMI functions, then skip this option. HAVE_SYSCALL_TRACEPOINTS ---------------------- +------------------------ You need very few things to get the syscalls tracing in an arch. @@ -250,12 +253,152 @@ You need very few things to get the syscalls tracing in an arch. HAVE_FTRACE_MCOUNT_RECORD ------------------------- -See scripts/recordmcount.pl for more info. +See scripts/recordmcount.pl for more info. Just fill in the arch-specific +details for how to locate the addresses of mcount call sites via objdump. +This option doesn't make much sense without also implementing dynamic ftrace. + +HAVE_DYNAMIC_FTRACE +------------------- + +You will first need HAVE_FTRACE_MCOUNT_RECORD and HAVE_FUNCTION_TRACER, so +scroll your reader back up if you got over eager. + +Once those are out of the way, you will need to implement: + - asm/ftrace.h: + - MCOUNT_ADDR + - ftrace_call_adjust() + - struct dyn_arch_ftrace{} + - asm code: + - mcount() (new stub) + - ftrace_caller() + - ftrace_call() + - ftrace_stub() + - C code: + - ftrace_dyn_arch_init() + - ftrace_make_nop() + - ftrace_make_call() + - ftrace_update_ftrace_func() + +First you will need to fill out some arch details in your asm/ftrace.h. + +Define MCOUNT_ADDR as the address of your mcount symbol similar to: + #define MCOUNT_ADDR ((unsigned long)mcount) +Since no one else will have a decl for that function, you will need to: + extern void mcount(void); + +You will also need the helper function ftrace_call_adjust(). Most people +will be able to stub it out like so: + static inline unsigned long ftrace_call_adjust(unsigned long addr) + { + return addr; + } <details to be filled> +Lastly you will need the custom dyn_arch_ftrace structure. If you need +some extra state when runtime patching arbitrary call sites, this is the +place. For now though, create an empty struct: + struct dyn_arch_ftrace { + /* No extra data needed */ + }; + +With the header out of the way, we can fill out the assembly code. While we +did already create a mcount() function earlier, dynamic ftrace only wants a +stub function. This is because the mcount() will only be used during boot +and then all references to it will be patched out never to return. Instead, +the guts of the old mcount() will be used to create a new ftrace_caller() +function. Because the two are hard to merge, it will most likely be a lot +easier to have two separate definitions split up by #ifdefs. Same goes for +the ftrace_stub() as that will now be inlined in ftrace_caller(). + +Before we get confused anymore, let's check out some pseudo code so you can +implement your own stuff in assembly: -HAVE_DYNAMIC_FTRACE ---------------------- +void mcount(void) +{ + return; +} + +void ftrace_caller(void) +{ + /* implement HAVE_FUNCTION_TRACE_MCOUNT_TEST if you desire */ + + /* save all state needed by the ABI (see paragraph above) */ + + unsigned long frompc = ...; + unsigned long selfpc = <return address> - MCOUNT_INSN_SIZE; + +ftrace_call: + ftrace_stub(frompc, selfpc); + + /* restore all state needed by the ABI */ + +ftrace_stub: + return; +} + +This might look a little odd at first, but keep in mind that we will be runtime +patching multiple things. First, only functions that we actually want to trace +will be patched to call ftrace_caller(). Second, since we only have one tracer +active at a time, we will patch the ftrace_caller() function itself to call the +specific tracer in question. That is the point of the ftrace_call label. + +With that in mind, let's move on to the C code that will actually be doing the +runtime patching. You'll need a little knowledge of your arch's opcodes in +order to make it through the next section. + +Every arch has an init callback function. If you need to do something early on +to initialize some state, this is the time to do that. Otherwise, this simple +function below should be sufficient for most people: + +int __init ftrace_dyn_arch_init(void *data) +{ + /* return value is done indirectly via data */ + *(unsigned long *)data = 0; + + return 0; +} + +There are two functions that are used to do runtime patching of arbitrary +functions. The first is used to turn the mcount call site into a nop (which +is what helps us retain runtime performance when not tracing). The second is +used to turn the mcount call site into a call to an arbitrary location (but +typically that is ftracer_caller()). See the general function definition in +linux/ftrace.h for the functions: + ftrace_make_nop() + ftrace_make_call() +The rec->ip value is the address of the mcount call site that was collected +by the scripts/recordmcount.pl during build time. + +The last function is used to do runtime patching of the active tracer. This +will be modifying the assembly code at the location of the ftrace_call symbol +inside of the ftrace_caller() function. So you should have sufficient padding +at that location to support the new function calls you'll be inserting. Some +people will be using a "call" type instruction while others will be using a +"branch" type instruction. Specifically, the function is: + ftrace_update_ftrace_func() + + +HAVE_DYNAMIC_FTRACE + HAVE_FUNCTION_GRAPH_TRACER +------------------------------------------------ + +The function grapher needs a few tweaks in order to work with dynamic ftrace. +Basically, you will need to: + - update: + - ftrace_caller() + - ftrace_graph_call() + - ftrace_graph_caller() + - implement: + - ftrace_enable_ftrace_graph_caller() + - ftrace_disable_ftrace_graph_caller() <details to be filled> +Quick notes: + - add a nop stub after the ftrace_call location named ftrace_graph_call; + stub needs to be large enough to support a call to ftrace_graph_caller() + - update ftrace_graph_caller() to work with being called by the new + ftrace_caller() since some semantics may have changed + - ftrace_enable_ftrace_graph_caller() will runtime patch the + ftrace_graph_call location with a call to ftrace_graph_caller() + - ftrace_disable_ftrace_graph_caller() will runtime patch the + ftrace_graph_call location with nops diff --git a/Documentation/trace/kmemtrace.txt b/Documentation/trace/kmemtrace.txt deleted file mode 100644 index 6308735..0000000 --- a/Documentation/trace/kmemtrace.txt +++ /dev/null @@ -1,126 +0,0 @@ - kmemtrace - Kernel Memory Tracer - - by Eduard - Gabriel Munteanu - <eduard.munteanu@linux360.ro> - -I. Introduction -=============== - -kmemtrace helps kernel developers figure out two things: -1) how different allocators (SLAB, SLUB etc.) perform -2) how kernel code allocates memory and how much - -To do this, we trace every allocation and export information to the userspace -through the relay interface. We export things such as the number of requested -bytes, the number of bytes actually allocated (i.e. including internal -fragmentation), whether this is a slab allocation or a plain kmalloc() and so -on. - -The actual analysis is performed by a userspace tool (see section III for -details on where to get it from). It logs the data exported by the kernel, -processes it and (as of writing this) can provide the following information: -- the total amount of memory allocated and fragmentation per call-site -- the amount of memory allocated and fragmentation per allocation -- total memory allocated and fragmentation in the collected dataset -- number of cross-CPU allocation and frees (makes sense in NUMA environments) - -Moreover, it can potentially find inconsistent and erroneous behavior in -kernel code, such as using slab free functions on kmalloc'ed memory or -allocating less memory than requested (but not truly failed allocations). - -kmemtrace also makes provisions for tracing on some arch and analysing the -data on another. - -II. Design and goals -==================== - -kmemtrace was designed to handle rather large amounts of data. Thus, it uses -the relay interface to export whatever is logged to userspace, which then -stores it. Analysis and reporting is done asynchronously, that is, after the -data is collected and stored. By design, it allows one to log and analyse -on different machines and different arches. - -As of writing this, the ABI is not considered stable, though it might not -change much. However, no guarantees are made about compatibility yet. When -deemed stable, the ABI should still allow easy extension while maintaining -backward compatibility. This is described further in Documentation/ABI. - -Summary of design goals: - - allow logging and analysis to be done across different machines - - be fast and anticipate usage in high-load environments (*) - - be reasonably extensible - - make it possible for GNU/Linux distributions to have kmemtrace - included in their repositories - -(*) - one of the reasons Pekka Enberg's original userspace data analysis - tool's code was rewritten from Perl to C (although this is more than a - simple conversion) - - -III. Quick usage guide -====================== - -1) Get a kernel that supports kmemtrace and build it accordingly (i.e. enable -CONFIG_KMEMTRACE). - -2) Get the userspace tool and build it: -$ git clone git://repo.or.cz/kmemtrace-user.git # current repository -$ cd kmemtrace-user/ -$ ./autogen.sh -$ ./configure -$ make - -3) Boot the kmemtrace-enabled kernel if you haven't, preferably in the -'single' runlevel (so that relay buffers don't fill up easily), and run -kmemtrace: -# '$' does not mean user, but root here. -$ mount -t debugfs none /sys/kernel/debug -$ mount -t proc none /proc -$ cd path/to/kmemtrace-user/ -$ ./kmemtraced -Wait a bit, then stop it with CTRL+C. -$ cat /sys/kernel/debug/kmemtrace/total_overruns # Check if we didn't - # overrun, should - # be zero. -$ (Optionally) [Run kmemtrace_check separately on each cpu[0-9]*.out file to - check its correctness] -$ ./kmemtrace-report - -Now you should have a nice and short summary of how the allocator performs. - -IV. FAQ and known issues -======================== - -Q: 'cat /sys/kernel/debug/kmemtrace/total_overruns' is non-zero, how do I fix -this? Should I worry? -A: If it's non-zero, this affects kmemtrace's accuracy, depending on how -large the number is. You can fix it by supplying a higher -'kmemtrace.subbufs=N' kernel parameter. ---- - -Q: kmemtrace_check reports errors, how do I fix this? Should I worry? -A: This is a bug and should be reported. It can occur for a variety of -reasons: - - possible bugs in relay code - - possible misuse of relay by kmemtrace - - timestamps being collected unorderly -Or you may fix it yourself and send us a patch. ---- - -Q: kmemtrace_report shows many errors, how do I fix this? Should I worry? -A: This is a known issue and I'm working on it. These might be true errors -in kernel code, which may have inconsistent behavior (e.g. allocating memory -with kmem_cache_alloc() and freeing it with kfree()). Pekka Enberg pointed -out this behavior may work with SLAB, but may fail with other allocators. - -It may also be due to lack of tracing in some unusual allocator functions. - -We don't want bug reports regarding this issue yet. ---- - -V. See also -=========== - -Documentation/kernel-parameters.txt -Documentation/ABI/testing/debugfs-kmemtrace - diff --git a/Documentation/trace/kprobetrace.txt b/Documentation/trace/kprobetrace.txt index ec94748..5f77d94 100644 --- a/Documentation/trace/kprobetrace.txt +++ b/Documentation/trace/kprobetrace.txt @@ -42,7 +42,7 @@ Synopsis of kprobe_events +|-offs(FETCHARG) : Fetch memory at FETCHARG +|- offs address.(**) NAME=FETCHARG : Set NAME as the argument name of FETCHARG. FETCHARG:TYPE : Set TYPE as the type of FETCHARG. Currently, basic types - (u8/u16/u32/u64/s8/s16/s32/s64) are supported. + (u8/u16/u32/u64/s8/s16/s32/s64) and string are supported. (*) only for return probe. (**) this is useful for fetching a field of data structures. diff --git a/Documentation/trace/postprocess/trace-vmscan-postprocess.pl b/Documentation/trace/postprocess/trace-vmscan-postprocess.pl new file mode 100644 index 0000000..1b55146 --- /dev/null +++ b/Documentation/trace/postprocess/trace-vmscan-postprocess.pl @@ -0,0 +1,686 @@ +#!/usr/bin/perl +# This is a POC for reading the text representation of trace output related to +# page reclaim. It makes an attempt to extract some high-level information on +# what is going on. The accuracy of the parser may vary +# +# Example usage: trace-vmscan-postprocess.pl < /sys/kernel/debug/tracing/trace_pipe +# other options +# --read-procstat If the trace lacks process info, get it from /proc +# --ignore-pid Aggregate processes of the same name together +# +# Copyright (c) IBM Corporation 2009 +# Author: Mel Gorman <mel@csn.ul.ie> +use strict; +use Getopt::Long; + +# Tracepoint events +use constant MM_VMSCAN_DIRECT_RECLAIM_BEGIN => 1; +use constant MM_VMSCAN_DIRECT_RECLAIM_END => 2; +use constant MM_VMSCAN_KSWAPD_WAKE => 3; +use constant MM_VMSCAN_KSWAPD_SLEEP => 4; +use constant MM_VMSCAN_LRU_SHRINK_ACTIVE => 5; +use constant MM_VMSCAN_LRU_SHRINK_INACTIVE => 6; +use constant MM_VMSCAN_LRU_ISOLATE => 7; +use constant MM_VMSCAN_WRITEPAGE_FILE_SYNC => 8; +use constant MM_VMSCAN_WRITEPAGE_ANON_SYNC => 9; +use constant MM_VMSCAN_WRITEPAGE_FILE_ASYNC => 10; +use constant MM_VMSCAN_WRITEPAGE_ANON_ASYNC => 11; +use constant MM_VMSCAN_WRITEPAGE_ASYNC => 12; +use constant EVENT_UNKNOWN => 13; + +# Per-order events +use constant MM_VMSCAN_DIRECT_RECLAIM_BEGIN_PERORDER => 11; +use constant MM_VMSCAN_WAKEUP_KSWAPD_PERORDER => 12; +use constant MM_VMSCAN_KSWAPD_WAKE_PERORDER => 13; +use constant HIGH_KSWAPD_REWAKEUP_PERORDER => 14; + +# Constants used to track state +use constant STATE_DIRECT_BEGIN => 15; +use constant STATE_DIRECT_ORDER => 16; +use constant STATE_KSWAPD_BEGIN => 17; +use constant STATE_KSWAPD_ORDER => 18; + +# High-level events extrapolated from tracepoints +use constant HIGH_DIRECT_RECLAIM_LATENCY => 19; +use constant HIGH_KSWAPD_LATENCY => 20; +use constant HIGH_KSWAPD_REWAKEUP => 21; +use constant HIGH_NR_SCANNED => 22; +use constant HIGH_NR_TAKEN => 23; +use constant HIGH_NR_RECLAIM => 24; +use constant HIGH_NR_CONTIG_DIRTY => 25; + +my %perprocesspid; +my %perprocess; +my %last_procmap; +my $opt_ignorepid; +my $opt_read_procstat; + +my $total_wakeup_kswapd; +my ($total_direct_reclaim, $total_direct_nr_scanned); +my ($total_direct_latency, $total_kswapd_latency); +my ($total_direct_writepage_file_sync, $total_direct_writepage_file_async); +my ($total_direct_writepage_anon_sync, $total_direct_writepage_anon_async); +my ($total_kswapd_nr_scanned, $total_kswapd_wake); +my ($total_kswapd_writepage_file_sync, $total_kswapd_writepage_file_async); +my ($total_kswapd_writepage_anon_sync, $total_kswapd_writepage_anon_async); + +# Catch sigint and exit on request +my $sigint_report = 0; +my $sigint_exit = 0; +my $sigint_pending = 0; +my $sigint_received = 0; +sub sigint_handler { + my $current_time = time; + if ($current_time - 2 > $sigint_received) { + print "SIGINT received, report pending. Hit ctrl-c again to exit\n"; + $sigint_report = 1; + } else { + if (!$sigint_exit) { + print "Second SIGINT received quickly, exiting\n"; + } + $sigint_exit++; + } + + if ($sigint_exit > 3) { + print "Many SIGINTs received, exiting now without report\n"; + exit; + } + + $sigint_received = $current_time; + $sigint_pending = 1; +} +$SIG{INT} = "sigint_handler"; + +# Parse command line options +GetOptions( + 'ignore-pid' => \$opt_ignorepid, + 'read-procstat' => \$opt_read_procstat, +); + +# Defaults for dynamically discovered regex's +my $regex_direct_begin_default = 'order=([0-9]*) may_writepage=([0-9]*) gfp_flags=([A-Z_|]*)'; +my $regex_direct_end_default = 'nr_reclaimed=([0-9]*)'; +my $regex_kswapd_wake_default = 'nid=([0-9]*) order=([0-9]*)'; +my $regex_kswapd_sleep_default = 'nid=([0-9]*)'; +my $regex_wakeup_kswapd_default = 'nid=([0-9]*) zid=([0-9]*) order=([0-9]*)'; +my $regex_lru_isolate_default = 'isolate_mode=([0-9]*) order=([0-9]*) nr_requested=([0-9]*) nr_scanned=([0-9]*) nr_taken=([0-9]*) contig_taken=([0-9]*) contig_dirty=([0-9]*) contig_failed=([0-9]*)'; +my $regex_lru_shrink_inactive_default = 'lru=([A-Z_]*) nr_scanned=([0-9]*) nr_reclaimed=([0-9]*) priority=([0-9]*)'; +my $regex_lru_shrink_active_default = 'lru=([A-Z_]*) nr_scanned=([0-9]*) nr_rotated=([0-9]*) priority=([0-9]*)'; +my $regex_writepage_default = 'page=([0-9a-f]*) pfn=([0-9]*) flags=([A-Z_|]*)'; + +# Dyanically discovered regex +my $regex_direct_begin; +my $regex_direct_end; +my $regex_kswapd_wake; +my $regex_kswapd_sleep; +my $regex_wakeup_kswapd; +my $regex_lru_isolate; +my $regex_lru_shrink_inactive; +my $regex_lru_shrink_active; +my $regex_writepage; + +# Static regex used. Specified like this for readability and for use with /o +# (process_pid) (cpus ) ( time ) (tpoint ) (details) +my $regex_traceevent = '\s*([a-zA-Z0-9-]*)\s*(\[[0-9]*\])\s*([0-9.]*):\s*([a-zA-Z_]*):\s*(.*)'; +my $regex_statname = '[-0-9]*\s\((.*)\).*'; +my $regex_statppid = '[-0-9]*\s\(.*\)\s[A-Za-z]\s([0-9]*).*'; + +sub generate_traceevent_regex { + my $event = shift; + my $default = shift; + my $regex; + + # Read the event format or use the default + if (!open (FORMAT, "/sys/kernel/debug/tracing/events/$event/format")) { + print("WARNING: Event $event format string not found\n"); + return $default; + } else { + my $line; + while (!eof(FORMAT)) { + $line = <FORMAT>; + $line =~ s/, REC->.*//; + if ($line =~ /^print fmt:\s"(.*)".*/) { + $regex = $1; + $regex =~ s/%s/\([0-9a-zA-Z|_]*\)/g; + $regex =~ s/%p/\([0-9a-f]*\)/g; + $regex =~ s/%d/\([-0-9]*\)/g; + $regex =~ s/%ld/\([-0-9]*\)/g; + $regex =~ s/%lu/\([0-9]*\)/g; + } + } + } + + # Can't handle the print_flags stuff but in the context of this + # script, it really doesn't matter + $regex =~ s/\(REC.*\) \? __print_flags.*//; + + # Verify fields are in the right order + my $tuple; + foreach $tuple (split /\s/, $regex) { + my ($key, $value) = split(/=/, $tuple); + my $expected = shift; + if ($key ne $expected) { + print("WARNING: Format not as expected for event $event '$key' != '$expected'\n"); + $regex =~ s/$key=\((.*)\)/$key=$1/; + } + } + + if (defined shift) { + die("Fewer fields than expected in format"); + } + + return $regex; +} + +$regex_direct_begin = generate_traceevent_regex( + "vmscan/mm_vmscan_direct_reclaim_begin", + $regex_direct_begin_default, + "order", "may_writepage", + "gfp_flags"); +$regex_direct_end = generate_traceevent_regex( + "vmscan/mm_vmscan_direct_reclaim_end", + $regex_direct_end_default, + "nr_reclaimed"); +$regex_kswapd_wake = generate_traceevent_regex( + "vmscan/mm_vmscan_kswapd_wake", + $regex_kswapd_wake_default, + "nid", "order"); +$regex_kswapd_sleep = generate_traceevent_regex( + "vmscan/mm_vmscan_kswapd_sleep", + $regex_kswapd_sleep_default, + "nid"); +$regex_wakeup_kswapd = generate_traceevent_regex( + "vmscan/mm_vmscan_wakeup_kswapd", + $regex_wakeup_kswapd_default, + "nid", "zid", "order"); +$regex_lru_isolate = generate_traceevent_regex( + "vmscan/mm_vmscan_lru_isolate", + $regex_lru_isolate_default, + "isolate_mode", "order", + "nr_requested", "nr_scanned", "nr_taken", + "contig_taken", "contig_dirty", "contig_failed"); +$regex_lru_shrink_inactive = generate_traceevent_regex( + "vmscan/mm_vmscan_lru_shrink_inactive", + $regex_lru_shrink_inactive_default, + "nid", "zid", + "lru", + "nr_scanned", "nr_reclaimed", "priority"); +$regex_lru_shrink_active = generate_traceevent_regex( + "vmscan/mm_vmscan_lru_shrink_active", + $regex_lru_shrink_active_default, + "nid", "zid", + "lru", + "nr_scanned", "nr_rotated", "priority"); +$regex_writepage = generate_traceevent_regex( + "vmscan/mm_vmscan_writepage", + $regex_writepage_default, + "page", "pfn", "flags"); + +sub read_statline($) { + my $pid = $_[0]; + my $statline; + + if (open(STAT, "/proc/$pid/stat")) { + $statline = <STAT>; + close(STAT); + } + + if ($statline eq '') { + $statline = "-1 (UNKNOWN_PROCESS_NAME) R 0"; + } + + return $statline; +} + +sub guess_process_pid($$) { + my $pid = $_[0]; + my $statline = $_[1]; + + if ($pid == 0) { + return "swapper-0"; + } + + if ($statline !~ /$regex_statname/o) { + die("Failed to math stat line for process name :: $statline"); + } + return "$1-$pid"; +} + +# Convert sec.usec timestamp format +sub timestamp_to_ms($) { + my $timestamp = $_[0]; + + my ($sec, $usec) = split (/\./, $timestamp); + return ($sec * 1000) + ($usec / 1000); +} + +sub process_events { + my $traceevent; + my $process_pid; + my $cpus; + my $timestamp; + my $tracepoint; + my $details; + my $statline; + + # Read each line of the event log +EVENT_PROCESS: + while ($traceevent = <STDIN>) { + if ($traceevent =~ /$regex_traceevent/o) { + $process_pid = $1; + $timestamp = $3; + $tracepoint = $4; + + $process_pid =~ /(.*)-([0-9]*)$/; + my $process = $1; + my $pid = $2; + + if ($process eq "") { + $process = $last_procmap{$pid}; + $process_pid = "$process-$pid"; + } + $last_procmap{$pid} = $process; + + if ($opt_read_procstat) { + $statline = read_statline($pid); + if ($opt_read_procstat && $process eq '') { + $process_pid = guess_process_pid($pid, $statline); + } + } + } else { + next; + } + + # Perl Switch() sucks majorly + if ($tracepoint eq "mm_vmscan_direct_reclaim_begin") { + $timestamp = timestamp_to_ms($timestamp); + $perprocesspid{$process_pid}->{MM_VMSCAN_DIRECT_RECLAIM_BEGIN}++; + $perprocesspid{$process_pid}->{STATE_DIRECT_BEGIN} = $timestamp; + + $details = $5; + if ($details !~ /$regex_direct_begin/o) { + print "WARNING: Failed to parse mm_vmscan_direct_reclaim_begin as expected\n"; + print " $details\n"; + print " $regex_direct_begin\n"; + next; + } + my $order = $1; + $perprocesspid{$process_pid}->{MM_VMSCAN_DIRECT_RECLAIM_BEGIN_PERORDER}[$order]++; + $perprocesspid{$process_pid}->{STATE_DIRECT_ORDER} = $order; + } elsif ($tracepoint eq "mm_vmscan_direct_reclaim_end") { + # Count the event itself + my $index = $perprocesspid{$process_pid}->{MM_VMSCAN_DIRECT_RECLAIM_END}; + $perprocesspid{$process_pid}->{MM_VMSCAN_DIRECT_RECLAIM_END}++; + + # Record how long direct reclaim took this time + if (defined $perprocesspid{$process_pid}->{STATE_DIRECT_BEGIN}) { + $timestamp = timestamp_to_ms($timestamp); + my $order = $perprocesspid{$process_pid}->{STATE_DIRECT_ORDER}; + my $latency = ($timestamp - $perprocesspid{$process_pid}->{STATE_DIRECT_BEGIN}); + $perprocesspid{$process_pid}->{HIGH_DIRECT_RECLAIM_LATENCY}[$index] = "$order-$latency"; + } + } elsif ($tracepoint eq "mm_vmscan_kswapd_wake") { + $details = $5; + if ($details !~ /$regex_kswapd_wake/o) { + print "WARNING: Failed to parse mm_vmscan_kswapd_wake as expected\n"; + print " $details\n"; + print " $regex_kswapd_wake\n"; + next; + } + + my $order = $2; + $perprocesspid{$process_pid}->{STATE_KSWAPD_ORDER} = $order; + if (!$perprocesspid{$process_pid}->{STATE_KSWAPD_BEGIN}) { + $timestamp = timestamp_to_ms($timestamp); + $perprocesspid{$process_pid}->{MM_VMSCAN_KSWAPD_WAKE}++; + $perprocesspid{$process_pid}->{STATE_KSWAPD_BEGIN} = $timestamp; + $perprocesspid{$process_pid}->{MM_VMSCAN_KSWAPD_WAKE_PERORDER}[$order]++; + } else { + $perprocesspid{$process_pid}->{HIGH_KSWAPD_REWAKEUP}++; + $perprocesspid{$process_pid}->{HIGH_KSWAPD_REWAKEUP_PERORDER}[$order]++; + } + } elsif ($tracepoint eq "mm_vmscan_kswapd_sleep") { + + # Count the event itself + my $index = $perprocesspid{$process_pid}->{MM_VMSCAN_KSWAPD_SLEEP}; + $perprocesspid{$process_pid}->{MM_VMSCAN_KSWAPD_SLEEP}++; + + # Record how long kswapd was awake + $timestamp = timestamp_to_ms($timestamp); + my $order = $perprocesspid{$process_pid}->{STATE_KSWAPD_ORDER}; + my $latency = ($timestamp - $perprocesspid{$process_pid}->{STATE_KSWAPD_BEGIN}); + $perprocesspid{$process_pid}->{HIGH_KSWAPD_LATENCY}[$index] = "$order-$latency"; + $perprocesspid{$process_pid}->{STATE_KSWAPD_BEGIN} = 0; + } elsif ($tracepoint eq "mm_vmscan_wakeup_kswapd") { + $perprocesspid{$process_pid}->{MM_VMSCAN_WAKEUP_KSWAPD}++; + + $details = $5; + if ($details !~ /$regex_wakeup_kswapd/o) { + print "WARNING: Failed to parse mm_vmscan_wakeup_kswapd as expected\n"; + print " $details\n"; + print " $regex_wakeup_kswapd\n"; + next; + } + my $order = $3; + $perprocesspid{$process_pid}->{MM_VMSCAN_WAKEUP_KSWAPD_PERORDER}[$order]++; + } elsif ($tracepoint eq "mm_vmscan_lru_isolate") { + $details = $5; + if ($details !~ /$regex_lru_isolate/o) { + print "WARNING: Failed to parse mm_vmscan_lru_isolate as expected\n"; + print " $details\n"; + print " $regex_lru_isolate/o\n"; + next; + } + my $nr_scanned = $4; + my $nr_contig_dirty = $7; + $perprocesspid{$process_pid}->{HIGH_NR_SCANNED} += $nr_scanned; + $perprocesspid{$process_pid}->{HIGH_NR_CONTIG_DIRTY} += $nr_contig_dirty; + } elsif ($tracepoint eq "mm_vmscan_writepage") { + $details = $5; + if ($details !~ /$regex_writepage/o) { + print "WARNING: Failed to parse mm_vmscan_writepage as expected\n"; + print " $details\n"; + print " $regex_writepage\n"; + next; + } + + my $flags = $3; + my $file = 0; + my $sync_io = 0; + if ($flags =~ /RECLAIM_WB_FILE/) { + $file = 1; + } + if ($flags =~ /RECLAIM_WB_SYNC/) { + $sync_io = 1; + } + if ($sync_io) { + if ($file) { + $perprocesspid{$process_pid}->{MM_VMSCAN_WRITEPAGE_FILE_SYNC}++; + } else { + $perprocesspid{$process_pid}->{MM_VMSCAN_WRITEPAGE_ANON_SYNC}++; + } + } else { + if ($file) { + $perprocesspid{$process_pid}->{MM_VMSCAN_WRITEPAGE_FILE_ASYNC}++; + } else { + $perprocesspid{$process_pid}->{MM_VMSCAN_WRITEPAGE_ANON_ASYNC}++; + } + } + } else { + $perprocesspid{$process_pid}->{EVENT_UNKNOWN}++; + } + + if ($sigint_pending) { + last EVENT_PROCESS; + } + } +} + +sub dump_stats { + my $hashref = shift; + my %stats = %$hashref; + + # Dump per-process stats + my $process_pid; + my $max_strlen = 0; + + # Get the maximum process name + foreach $process_pid (keys %perprocesspid) { + my $len = length($process_pid); + if ($len > $max_strlen) { + $max_strlen = $len; + } + } + $max_strlen += 2; + + # Work out latencies + printf("\n") if !$opt_ignorepid; + printf("Reclaim latencies expressed as order-latency_in_ms\n") if !$opt_ignorepid; + foreach $process_pid (keys %stats) { + + if (!$stats{$process_pid}->{HIGH_DIRECT_RECLAIM_LATENCY}[0] && + !$stats{$process_pid}->{HIGH_KSWAPD_LATENCY}[0]) { + next; + } + + printf "%-" . $max_strlen . "s ", $process_pid if !$opt_ignorepid; + my $index = 0; + while (defined $stats{$process_pid}->{HIGH_DIRECT_RECLAIM_LATENCY}[$index] || + defined $stats{$process_pid}->{HIGH_KSWAPD_LATENCY}[$index]) { + + if ($stats{$process_pid}->{HIGH_DIRECT_RECLAIM_LATENCY}[$index]) { + printf("%s ", $stats{$process_pid}->{HIGH_DIRECT_RECLAIM_LATENCY}[$index]) if !$opt_ignorepid; + my ($dummy, $latency) = split(/-/, $stats{$process_pid}->{HIGH_DIRECT_RECLAIM_LATENCY}[$index]); + $total_direct_latency += $latency; + } else { + printf("%s ", $stats{$process_pid}->{HIGH_KSWAPD_LATENCY}[$index]) if !$opt_ignorepid; + my ($dummy, $latency) = split(/-/, $stats{$process_pid}->{HIGH_KSWAPD_LATENCY}[$index]); + $total_kswapd_latency += $latency; + } + $index++; + } + print "\n" if !$opt_ignorepid; + } + + # Print out process activity + printf("\n"); + printf("%-" . $max_strlen . "s %8s %10s %8s %8s %8s %8s %8s\n", "Process", "Direct", "Wokeup", "Pages", "Pages", "Pages", "Time"); + printf("%-" . $max_strlen . "s %8s %10s %8s %8s %8s %8s %8s\n", "details", "Rclms", "Kswapd", "Scanned", "Sync-IO", "ASync-IO", "Stalled"); + foreach $process_pid (keys %stats) { + + if (!$stats{$process_pid}->{MM_VMSCAN_DIRECT_RECLAIM_BEGIN}) { + next; + } + + $total_direct_reclaim += $stats{$process_pid}->{MM_VMSCAN_DIRECT_RECLAIM_BEGIN}; + $total_wakeup_kswapd += $stats{$process_pid}->{MM_VMSCAN_WAKEUP_KSWAPD}; + $total_direct_nr_scanned += $stats{$process_pid}->{HIGH_NR_SCANNED}; + $total_direct_writepage_file_sync += $stats{$process_pid}->{MM_VMSCAN_WRITEPAGE_FILE_SYNC}; + $total_direct_writepage_anon_sync += $stats{$process_pid}->{MM_VMSCAN_WRITEPAGE_ANON_SYNC}; + $total_direct_writepage_file_async += $stats{$process_pid}->{MM_VMSCAN_WRITEPAGE_FILE_ASYNC}; + + $total_direct_writepage_anon_async += $stats{$process_pid}->{MM_VMSCAN_WRITEPAGE_ANON_ASYNC}; + + my $index = 0; + my $this_reclaim_delay = 0; + while (defined $stats{$process_pid}->{HIGH_DIRECT_RECLAIM_LATENCY}[$index]) { + my ($dummy, $latency) = split(/-/, $stats{$process_pid}->{HIGH_DIRECT_RECLAIM_LATENCY}[$index]); + $this_reclaim_delay += $latency; + $index++; + } + + printf("%-" . $max_strlen . "s %8d %10d %8u %8u %8u %8.3f", + $process_pid, + $stats{$process_pid}->{MM_VMSCAN_DIRECT_RECLAIM_BEGIN}, + $stats{$process_pid}->{MM_VMSCAN_WAKEUP_KSWAPD}, + $stats{$process_pid}->{HIGH_NR_SCANNED}, + $stats{$process_pid}->{MM_VMSCAN_WRITEPAGE_FILE_SYNC} + $stats{$process_pid}->{MM_VMSCAN_WRITEPAGE_ANON_SYNC}, + $stats{$process_pid}->{MM_VMSCAN_WRITEPAGE_FILE_ASYNC} + $stats{$process_pid}->{MM_VMSCAN_WRITEPAGE_ANON_ASYNC}, + $this_reclaim_delay / 1000); + + if ($stats{$process_pid}->{MM_VMSCAN_DIRECT_RECLAIM_BEGIN}) { + print " "; + for (my $order = 0; $order < 20; $order++) { + my $count = $stats{$process_pid}->{MM_VMSCAN_DIRECT_RECLAIM_BEGIN_PERORDER}[$order]; + if ($count != 0) { + print "direct-$order=$count "; + } + } + } + if ($stats{$process_pid}->{MM_VMSCAN_WAKEUP_KSWAPD}) { + print " "; + for (my $order = 0; $order < 20; $order++) { + my $count = $stats{$process_pid}->{MM_VMSCAN_WAKEUP_KSWAPD_PERORDER}[$order]; + if ($count != 0) { + print "wakeup-$order=$count "; + } + } + } + if ($stats{$process_pid}->{HIGH_NR_CONTIG_DIRTY}) { + print " "; + my $count = $stats{$process_pid}->{HIGH_NR_CONTIG_DIRTY}; + if ($count != 0) { + print "contig-dirty=$count "; + } + } + + print "\n"; + } + + # Print out kswapd activity + printf("\n"); + printf("%-" . $max_strlen . "s %8s %10s %8s %8s %8s %8s\n", "Kswapd", "Kswapd", "Order", "Pages", "Pages", "Pages"); + printf("%-" . $max_strlen . "s %8s %10s %8s %8s %8s %8s\n", "Instance", "Wakeups", "Re-wakeup", "Scanned", "Sync-IO", "ASync-IO"); + foreach $process_pid (keys %stats) { + + if (!$stats{$process_pid}->{MM_VMSCAN_KSWAPD_WAKE}) { + next; + } + + $total_kswapd_wake += $stats{$process_pid}->{MM_VMSCAN_KSWAPD_WAKE}; + $total_kswapd_nr_scanned += $stats{$process_pid}->{HIGH_NR_SCANNED}; + $total_kswapd_writepage_file_sync += $stats{$process_pid}->{MM_VMSCAN_WRITEPAGE_FILE_SYNC}; + $total_kswapd_writepage_anon_sync += $stats{$process_pid}->{MM_VMSCAN_WRITEPAGE_ANON_SYNC}; + $total_kswapd_writepage_file_async += $stats{$process_pid}->{MM_VMSCAN_WRITEPAGE_FILE_ASYNC}; + $total_kswapd_writepage_anon_async += $stats{$process_pid}->{MM_VMSCAN_WRITEPAGE_ANON_ASYNC}; + + printf("%-" . $max_strlen . "s %8d %10d %8u %8i %8u", + $process_pid, + $stats{$process_pid}->{MM_VMSCAN_KSWAPD_WAKE}, + $stats{$process_pid}->{HIGH_KSWAPD_REWAKEUP}, + $stats{$process_pid}->{HIGH_NR_SCANNED}, + $stats{$process_pid}->{MM_VMSCAN_WRITEPAGE_FILE_SYNC} + $stats{$process_pid}->{MM_VMSCAN_WRITEPAGE_ANON_SYNC}, + $stats{$process_pid}->{MM_VMSCAN_WRITEPAGE_FILE_ASYNC} + $stats{$process_pid}->{MM_VMSCAN_WRITEPAGE_ANON_ASYNC}); + + if ($stats{$process_pid}->{MM_VMSCAN_KSWAPD_WAKE}) { + print " "; + for (my $order = 0; $order < 20; $order++) { + my $count = $stats{$process_pid}->{MM_VMSCAN_KSWAPD_WAKE_PERORDER}[$order]; + if ($count != 0) { + print "wake-$order=$count "; + } + } + } + if ($stats{$process_pid}->{HIGH_KSWAPD_REWAKEUP}) { + print " "; + for (my $order = 0; $order < 20; $order++) { + my $count = $stats{$process_pid}->{HIGH_KSWAPD_REWAKEUP_PERORDER}[$order]; + if ($count != 0) { + print "rewake-$order=$count "; + } + } + } + printf("\n"); + } + + # Print out summaries + $total_direct_latency /= 1000; + $total_kswapd_latency /= 1000; + print "\nSummary\n"; + print "Direct reclaims: $total_direct_reclaim\n"; + print "Direct reclaim pages scanned: $total_direct_nr_scanned\n"; + print "Direct reclaim write file sync I/O: $total_direct_writepage_file_sync\n"; + print "Direct reclaim write anon sync I/O: $total_direct_writepage_anon_sync\n"; + print "Direct reclaim write file async I/O: $total_direct_writepage_file_async\n"; + print "Direct reclaim write anon async I/O: $total_direct_writepage_anon_async\n"; + print "Wake kswapd requests: $total_wakeup_kswapd\n"; + printf "Time stalled direct reclaim: %-1.2f seconds\n", $total_direct_latency; + print "\n"; + print "Kswapd wakeups: $total_kswapd_wake\n"; + print "Kswapd pages scanned: $total_kswapd_nr_scanned\n"; + print "Kswapd reclaim write file sync I/O: $total_kswapd_writepage_file_sync\n"; + print "Kswapd reclaim write anon sync I/O: $total_kswapd_writepage_anon_sync\n"; + print "Kswapd reclaim write file async I/O: $total_kswapd_writepage_file_async\n"; + print "Kswapd reclaim write anon async I/O: $total_kswapd_writepage_anon_async\n"; + printf "Time kswapd awake: %-1.2f seconds\n", $total_kswapd_latency; +} + +sub aggregate_perprocesspid() { + my $process_pid; + my $process; + undef %perprocess; + + foreach $process_pid (keys %perprocesspid) { + $process = $process_pid; + $process =~ s/-([0-9])*$//; + if ($process eq '') { + $process = "NO_PROCESS_NAME"; + } + + $perprocess{$process}->{MM_VMSCAN_DIRECT_RECLAIM_BEGIN} += $perprocesspid{$process_pid}->{MM_VMSCAN_DIRECT_RECLAIM_BEGIN}; + $perprocess{$process}->{MM_VMSCAN_KSWAPD_WAKE} += $perprocesspid{$process_pid}->{MM_VMSCAN_KSWAPD_WAKE}; + $perprocess{$process}->{MM_VMSCAN_WAKEUP_KSWAPD} += $perprocesspid{$process_pid}->{MM_VMSCAN_WAKEUP_KSWAPD}; + $perprocess{$process}->{HIGH_KSWAPD_REWAKEUP} += $perprocesspid{$process_pid}->{HIGH_KSWAPD_REWAKEUP}; + $perprocess{$process}->{HIGH_NR_SCANNED} += $perprocesspid{$process_pid}->{HIGH_NR_SCANNED}; + $perprocess{$process}->{MM_VMSCAN_WRITEPAGE_FILE_SYNC} += $perprocesspid{$process_pid}->{MM_VMSCAN_WRITEPAGE_FILE_SYNC}; + $perprocess{$process}->{MM_VMSCAN_WRITEPAGE_ANON_SYNC} += $perprocesspid{$process_pid}->{MM_VMSCAN_WRITEPAGE_ANON_SYNC}; + $perprocess{$process}->{MM_VMSCAN_WRITEPAGE_FILE_ASYNC} += $perprocesspid{$process_pid}->{MM_VMSCAN_WRITEPAGE_FILE_ASYNC}; + $perprocess{$process}->{MM_VMSCAN_WRITEPAGE_ANON_ASYNC} += $perprocesspid{$process_pid}->{MM_VMSCAN_WRITEPAGE_ANON_ASYNC}; + + for (my $order = 0; $order < 20; $order++) { + $perprocess{$process}->{MM_VMSCAN_DIRECT_RECLAIM_BEGIN_PERORDER}[$order] += $perprocesspid{$process_pid}->{MM_VMSCAN_DIRECT_RECLAIM_BEGIN_PERORDER}[$order]; + $perprocess{$process}->{MM_VMSCAN_WAKEUP_KSWAPD_PERORDER}[$order] += $perprocesspid{$process_pid}->{MM_VMSCAN_WAKEUP_KSWAPD_PERORDER}[$order]; + $perprocess{$process}->{MM_VMSCAN_KSWAPD_WAKE_PERORDER}[$order] += $perprocesspid{$process_pid}->{MM_VMSCAN_KSWAPD_WAKE_PERORDER}[$order]; + + } + + # Aggregate direct reclaim latencies + my $wr_index = $perprocess{$process}->{MM_VMSCAN_DIRECT_RECLAIM_END}; + my $rd_index = 0; + while (defined $perprocesspid{$process_pid}->{HIGH_DIRECT_RECLAIM_LATENCY}[$rd_index]) { + $perprocess{$process}->{HIGH_DIRECT_RECLAIM_LATENCY}[$wr_index] = $perprocesspid{$process_pid}->{HIGH_DIRECT_RECLAIM_LATENCY}[$rd_index]; + $rd_index++; + $wr_index++; + } + $perprocess{$process}->{MM_VMSCAN_DIRECT_RECLAIM_END} = $wr_index; + + # Aggregate kswapd latencies + my $wr_index = $perprocess{$process}->{MM_VMSCAN_KSWAPD_SLEEP}; + my $rd_index = 0; + while (defined $perprocesspid{$process_pid}->{HIGH_KSWAPD_LATENCY}[$rd_index]) { + $perprocess{$process}->{HIGH_KSWAPD_LATENCY}[$wr_index] = $perprocesspid{$process_pid}->{HIGH_KSWAPD_LATENCY}[$rd_index]; + $rd_index++; + $wr_index++; + } + $perprocess{$process}->{MM_VMSCAN_DIRECT_RECLAIM_END} = $wr_index; + } +} + +sub report() { + if (!$opt_ignorepid) { + dump_stats(\%perprocesspid); + } else { + aggregate_perprocesspid(); + dump_stats(\%perprocess); + } +} + +# Process events or signals until neither is available +sub signal_loop() { + my $sigint_processed; + do { + $sigint_processed = 0; + process_events(); + + # Handle pending signals if any + if ($sigint_pending) { + my $current_time = time; + + if ($sigint_exit) { + print "Received exit signal\n"; + $sigint_pending = 0; + } + if ($sigint_report) { + if ($current_time >= $sigint_received + 2) { + report(); + $sigint_report = 0; + $sigint_pending = 0; + $sigint_processed = 1; + } + } + } + } while ($sigint_pending || $sigint_processed); +} + +signal_loop(); +report(); |