Re: Can't find the revelant commit with git-log
- From
- Francis Moreau <francis.moro@gmail.com>
- Date
- Jan 26, 2011, 08:36 UTC
- Message-ID
- <m239og12pe.fsf@gmail.com>
- In-Reply-To
- <m2ipxc27zi.fsf@gmail.com>
Francis Moreau <francis.moro@gmail.com> writes:
Show 99 quoted lines
> René Scharfe <rene.scharfe@lsrfire.ath.cx> writes: > >> Am 25.01.2011 10:01, schrieb Francis Moreau: >>> >>> The project is the Linux kernel, and I'm trying to look for changes >>> which happened between v2.6.27 and v2.6.28. The changes happened in the >>> following file: drivers/pci/intel-iommu.c where a function has been >>> removed: >>> >>> $ git --version >>> git version 1.7.4.rc3 >>> >>> $ cd ~/linux-2.6/drivers/pci/ >>> $ git grep blacklist v2.6.27 -- drivers/pci/intel-iommu.c >>> $ >>> >>> No ouput... hmm, I know it's in... oh maybe the path is incorrect >>> >>> $ git git grep blacklist v2.6.27 -- intel-iommu.c >>> v2.6.27:intel-iommu.c:static int blacklist_iommu(const struct dmi_system_id *id) >>> v2.6.27:intel-iommu.c: .callback = blacklist_iommu, >>> >>> ah, so Git failed previously without any comments on the wrong >>> path... maybe it should ? >> >> Good idea. >> > > Actually I _think_ I encoutered this behaviour for other commands as well, > like git-show or git-log, I don't remember. > >> >>> So at that point I know that in the revision v2.6.27, there's a function >>> called "blacklist_iommu" in drivers/pci/intel-iommu.c >>> >>> Now take a look if it's still there in v2.6.28: >>> >>> $ git git grep blacklist v2.6.28 -- intel-iommu.c >>> $ >>> >>> This time nothing is printed but I know that the command is correct. >>> >>> So now I'm interested in looking for the commit which removed this >>> function. Fo this I'm trying to use git-log(1): >>> >>> $ git log --full-history --follow -S'static int blacklist_iommu(const struct dmi_system_id *id)' v2.6.27..v2.6.28 -- intel-iommu.c >>> $ echo $? >>> 0 >>> >>> I tried different options but it fails. >>> >>> Also I found that passing the exact string to '-S' is annoying, are >>> there any way to just pass a part of the string such as >>> "-Sblacklist_iommu" ? >> >> This (-Sblacklist_iommu) works for me. >> > > Hmm, I thought I tried this and it didn't work, but that's obviously > wrong. > >> >>> Sorry if I miss the revelant git-log's option, but there're so many... >> >> Try -m (show full diff for merge commits), as the change you're looking >> for seems to have been introduced by a merge, not a regular commit. >> >> $ opts="--stat -Sblacklist_iommu -m --oneline" >> $ revs="v2.6.27..v2.6.28" >> >> $ git log $opts $revs -- drivers/pci/intel-iommu.c >> >> This returns nothing. Hmm. Let's try this instead: >> >> $ git log $opts $revs -- drivers/pci/ >> 057316c (from 3e2dab9) Merge branch 'linus' into test >> drivers/pci/intel-iommu.c | 307 ++++++++++++++++++++------------------------ >> 1 files changed, 140 insertions(+), 167 deletions(-) >> 6b2ada8 (from 3b7ecb5) Merge branches 'core/softlockup', 'core/softirq', 'core/resources', 'core/printk' and 'core/misc' into core-v28-for-linus >> drivers/pci/intel-iommu.c | 187 ++++++-------------------------------------- >> 1 files changed, 26 insertions(+), 161 deletions(-) >> d847059 (from 725c258) Merge branch 'x86/apic' into x86-v28-for-linus-phase4-B >> drivers/pci/intel-iommu.c | 185 ++++++--------------------------------------- >> 1 files changed, 25 insertions(+), 160 deletions(-) >> 725c258 (from 129d6ab) Merge branches 'core/iommu', 'x86/amd-iommu' and 'x86/iommu' into x86-v28-for-linus-phase3-B >> drivers/pci/intel-iommu.c | 25 ++++++++++++++++++++++++- >> 1 files changed, 24 insertions(+), 1 deletions(-) >> 6e03f99 (from 9821626) Merge branch 'linus' into x86/iommu >> drivers/pci/intel-iommu.c | 23 +++++++++++++++++++++++ >> 1 files changed, 23 insertions(+), 0 deletions(-) >> >> Strange, why did we need to remove the last path component to get these >> results which say that exactly the file we previously specified was changed? > > ah... I think I've been hit by this, since I tried '-m' too but see > nothing and was not smart enough to remove the filename from the path. > >> Also interesting, and matching the above results in that we see the need for >> the -m flag confirmed:
BTW, couldn't '-m' automatically set when '-S' is given ?
Show 72 quoted lines
>> >> >> $ for merge in 057316c 6b2ada8 d847059 725c258 6e03f99 >> do >> a=$(git show $merge | grep -c blacklist_iommu) >> b=$(git show -m $merge | grep -c blacklist_iommu) >> echo $merge $a $b >> done >> 057316c 0 2 >> 6b2ada8 0 2 >> d847059 0 2 >> 725c258 0 2 >> 6e03f99 0 2 >> >> IAW: the combined diff for the five found merges doesn't show any changes to >> a line containing the string "blacklist_iommu", but the full diffs do. >> >> Let's check for the presence of the string in the merge results and their >> parents: >> >> $ for merge in 057316c 6b2ada8 d847059 725c258 6e03f99 >> do >> for rev in $(git show $merge | grep ^Merge:) >> do >> t=parent >> case $rev in >> Merge:) >> echo >> rev=$merge >> t=merge >> ;; >> esac >> if git grep -q blacklist_iommu $rev -- drivers/pci/ >> then >> echo "$t $rev: found" >> else >> echo "$t $rev: not found" >> fi >> done >> done >> >> merge 057316c: not found >> parent 3e2dab9: found >> parent 2515ddc: not found >> >> merge 6b2ada8: not found >> parent 278429c: not found >> parent 3b7ecb5: found >> parent 77af7e3: not found >> parent 1516071: not found >> parent 1fa63a8: not found >> parent 8546232: not found >> >> merge d847059: not found >> parent 725c258: found >> parent 11494547: not found >> >> merge 725c258: found >> parent 3dd392a: found >> parent 72d3105: found >> parent 129d6ab: not found >> parent 1e19b16: found >> >> merge 6e03f99: found >> parent 9821626: not found >> parent 6bfb09a: found >> >> Hmm, seems like the function is gone since d847059. Does all of this help >> you in any way? > > Yes it does, but one question I'm wondering is: is it possible to do > this more user friendly ? ;)
I tried to reproduce something similar but with a far more simple repo:
<v2.6.28> 1.f o
|
1.e o (merge)
| \
1.d o o 2.c (merge)
| | \
1.c o o o 3.a "Remove blacklist_iommu()"
| | /
| o 2.a
| /
1.b o
|
<v2.6.27> 1.a o "Introduce blacklist_iommu()"
|
o InitBasically this repo 3 branches: master, 2, 3. Master branch introduces the "blacklist_iommu()" function with commit 1.a, and branch "3" removes it at commit 3.a.
So now:
$ git log --oneline -S"blacklist_iommu" ea1ddb0 3.a 8053460 1.a
$ git show :/3.a
commit ea1ddb023833470be173363a71a3a055ae8acb85
Author: Francis Moreau <fmoreau@spoutnik.(none)>
Date: Wed Jan 26 09:17:58 2011 +0100
3.a
Remove blacklist_iommy()
diff --git a/intel-iommu.c b/intel-iommu.c
index 2c9539d..f19c1cc 100644
--- a/intel-iommu.c
+++ b/intel-iommu.c
@@ -2,12 +2,4 @@ Wed Jan 26 09:10:15 CET 2011
Wed Jan 26 09:16:23 CET 2011
-static int blacklist_iommu(const struct dmi_system_id *id)
-{
- printk(KERN_INFO "%s detected; disabling IOMMU\n",
- id->ident);
- dmar_disabled = 1;
- return 0;
-}
-
Wed Jan 26 09:14:40 CET 2011So in this case there's no need to pass the '-m' flag and git-log(1), by default walks through all the commits:
$ git log --oneline v2.6.27..v2.6.28 e2a5af3 1.e c9fbd3a Merge branch '2' a8207d9 Merge branch '3' into 2 ea1ddb0 3.a 3a86ada 2.b 767186a 2.a 45beaac 1.d 1af781c 1.c 4f9b5c1 1.b 8053460 1.a
whereas in my previous example, it doesn't seem to be true.
Could you shed some light ?
Thanks
-- Francis