On 20/10/15 22:24, Junio C Hamano wrote:
> Junio C Hamano <gitster@xxxxxxxxx> writes:
>
>> During the discussion on the recent "git am" regression, I noticed
>> that the command reimplemented in C spawns one "mailsplit" and then
>> spawns "mailinfo" followed by "apply --index" to commit the changes
>> described in each message. As there are platforms where spawning
>> subprocess via run_command() interface is heavy-weight, something
>> that is conceptually very simple like "mailinfo" is better called
>> directly inside the process---something that is lightweight and
>> frequently used is where the overhead of run_command() would be felt
>> most.
>
> Although I still haven't seen any offer to help from those who work
> on the platforms that may benefit from this series the most, I have
> some numbers on my desktop (Dell T3500 2.66GHz Xeon X5650 with 12GB,
> running Ubuntu), where the cost of spawning is not as costly as
> elsewhere, making this series less pressing.
I suspect that I haven't tested exactly the same version as you, but I had
a quick look at testing this on Cygwin today. I have included a complete
transcript (below), so you can see what I did wrong! :-P
>
> Between 'master' and the version with this series (on 'jch'),
> applying this 34-patch series itself on top of 'master' using "git
> am", best of 5 numbers for running:
>
> time git am mbox >/dev/null
>
> are
>
> (master) (with the series)
> real 0m0.648s real 0m0.537s
> user 0m0.358s user 0m0.338s
> sys 0m0.172s sys 0m0.154s
>
The corresponding times for me were:
(master) (with the series)
real 0m9.760s real 0m5.744s
user 0m0.531s user 0m0.656s
sys 0m5.726s sys 0m3.520s
So, yes, a noticeable improvement! :)
HTH
ATB,
Ramsay Jones
$ uname -a
CYGWIN_NT-6.3 satellite 2.2.1(0.289/5/3) 2015-08-20 11:42 x86_64 Cygwin
$ pwd
/home/ramsay/git
$ git log --decorate --oneline -1
74301d6 (HEAD -> master, origin/master, origin/HEAD) Sync with maint
$ ./git version
git version 2.6.2.280.g74301d6
$ git format-patch --stdout 2a5ce7c^..896df93 >mailinfo.mbox
$ git format-patch --stdout a4106a8^..559e247 >>mailinfo.mbox
$ git checkout -b master-mailinfo master
Switched to a new branch 'master-mailinfo'
$ time ./git am mailinfo.mbox
Applying: mailinfo: remove a no-op call convert_to_utf8(it, "")
Applying: mailinfo: fold decode_header_bq() into decode_header()
Applying: mailinfo: fix an off-by-one error in the boundary stack
Applying: mailinfo: explicitly close file handle to the patch output
Applying: mailinfo: move handle_boundary() lower
Applying: mailinfo: get rid of function-local static states
Applying: mailinfo: do not let handle_body() touch global "line" directly
Applying: mailinfo: do not let handle_boundary() touch global "line" directly
Applying: mailinfo: do not let find_boundary() touch global "line" directly
Applying: mailinfo: move global "line" into mailinfo() function
Applying: mailinfo: introduce "struct mailinfo" to hold globals
Applying: mailinfo: move keep_subject & keep_non_patch_bracket to struct mailinfo
Applying: mailinfo: move global "FILE *fin, *fout" to struct mailinfo
Applying: mailinfo: move filter/header stage to struct mailinfo
Applying: mailinfo: move patch_lines to struct mailinfo
Applying: mailinfo: move add_message_id and message_id to struct mailinfo
Applying: mailinfo: move use_scissors and use_inbody_headers to struct mailinfo
Applying: mailinfo: move metainfo_charset to struct mailinfo
Applying: mailinfo: move check for metainfo_charset to convert_to_utf8()
Applying: mailinfo: move transfer_encoding to struct mailinfo
Applying: mailinfo: move charset to struct mailinfo
Applying: mailinfo: move cmitmsg and patchfile to struct mailinfo
Applying: mailinfo: move [ps]_hdr_data to struct mailinfo
Applying: mailinfo: move content/content_top to struct mailinfo
Applying: mailinfo: handle_commit_msg() shouldn't be called after finding patchbreak
Applying: mailinfo: keep the parsed log message in a strbuf
Applying: mailinfo: move read_one_header_line() closer to its callers
Applying: mailinfo: move check_header() after the helpers it uses
Applying: mailinfo: move cleanup_space() before its users
Applying: mailinfo: move definition of MAX_HDR_PARSED closer to its use
Applying: mailinfo: libify
Applying: mailinfo: handle charset conversion errors in the caller
Applying: mailinfo: remove calls to exit() and die() deep in the callchain
Applying: am: make direct call to mailinfo
Applying: mailinfo: plug strbuf leak during continuation line handling
real 0m9.760s
user 0m0.531s
sys 0m5.726s
$
$ make clean >/dev/null 2>&1
$ make >out.mi 2>&1
$ ./git version
git version 2.6.2.315.g1e9f6ff
$ git describe
v2.6.2-315-g1e9f6ff
$ git checkout -b new-mailinfo master
Switched to a new branch 'new-mailinfo'
$ time ./git am mailinfo.mbox
Applying: mailinfo: remove a no-op call convert_to_utf8(it, "")
Applying: mailinfo: fold decode_header_bq() into decode_header()
Applying: mailinfo: fix an off-by-one error in the boundary stack
Applying: mailinfo: explicitly close file handle to the patch output
Applying: mailinfo: move handle_boundary() lower
Applying: mailinfo: get rid of function-local static states
Applying: mailinfo: do not let handle_body() touch global "line" directly
Applying: mailinfo: do not let handle_boundary() touch global "line" directly
Applying: mailinfo: do not let find_boundary() touch global "line" directly
Applying: mailinfo: move global "line" into mailinfo() function
Applying: mailinfo: introduce "struct mailinfo" to hold globals
Applying: mailinfo: move keep_subject & keep_non_patch_bracket to struct mailinfo
Applying: mailinfo: move global "FILE *fin, *fout" to struct mailinfo
Applying: mailinfo: move filter/header stage to struct mailinfo
Applying: mailinfo: move patch_lines to struct mailinfo
Applying: mailinfo: move add_message_id and message_id to struct mailinfo
Applying: mailinfo: move use_scissors and use_inbody_headers to struct mailinfo
Applying: mailinfo: move metainfo_charset to struct mailinfo
Applying: mailinfo: move check for metainfo_charset to convert_to_utf8()
Applying: mailinfo: move transfer_encoding to struct mailinfo
Applying: mailinfo: move charset to struct mailinfo
Applying: mailinfo: move cmitmsg and patchfile to struct mailinfo
Applying: mailinfo: move [ps]_hdr_data to struct mailinfo
Applying: mailinfo: move content/content_top to struct mailinfo
Applying: mailinfo: handle_commit_msg() shouldn't be called after finding patchbreak
Applying: mailinfo: keep the parsed log message in a strbuf
Applying: mailinfo: move read_one_header_line() closer to its callers
Applying: mailinfo: move check_header() after the helpers it uses
Applying: mailinfo: move cleanup_space() before its users
Applying: mailinfo: move definition of MAX_HDR_PARSED closer to its use
Applying: mailinfo: libify
Applying: mailinfo: handle charset conversion errors in the caller
Applying: mailinfo: remove calls to exit() and die() deep in the callchain
Applying: am: make direct call to mailinfo
Applying: mailinfo: plug strbuf leak during continuation line handling
real 0m5.744s
user 0m0.656s
sys 0m3.520s
$
$ git rev-parse master-mailinfo^{tree} new-mailinfo^{tree}
cebb1a110f3af9f4393bb66b942ae28e2743f233
cebb1a110f3af9f4393bb66b942ae28e2743f233
$
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