* pahole BRAIN FART ALERT on F12 @ 2009-11-23 22:17 Mike Snitzer [not found] ` <20091123221703.GA10860-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> 0 siblings, 1 reply; 7+ messages in thread From: Mike Snitzer @ 2009-11-23 22:17 UTC (permalink / raw) To: Arnaldo de Melo; +Cc: dwarves-u79uwXL29TY76Z2rM5mHXA Hi, I just found out about pahole today. I'm looking to audit lvm2's data structures and pahole is perfect for helping me do so. Unfortunately, when I run pahole against lvm2 I'm getting many BRAIN FART ALERTs on F12 x86_64 (dwarves-1.7-5.x86_64). I had a look at your OLS 2007 "7 dwarves" paper and figured I'd try your minimalist swiss_cheese example, this is what I get: $ pahole swiss_cheese struct cheese { char name[17]; /* 0 17 */ short int age; /* 0 2 */ char type; /* 0 1 */ int calories; /* 0 4 */ short int price; /* 0 2 */ int barcode[4]; /* 0 16 */ /* size: 48, cachelines: 1, members: 6 */ /* padding: 32 */ /* last cacheline: 48 bytes */ /* BRAIN FART ALERT! 48 != 17 + 0(holes), diff = 31 */ }; When I compare the above to the output listed in your paper it is clear pahole is pretty unhappy on F12. If I do the same on F11 (x86_64) all works fine. Should I open a fedora (F12) bug? Mike -- To unsubscribe from this list: send the line "unsubscribe dwarves" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html ^ permalink raw reply [flat|nested] 7+ messages in thread
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* Re: pahole BRAIN FART ALERT on F12 [not found] ` <20091123221703.GA10860-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> @ 2009-11-23 22:49 ` Arnaldo de Melo [not found] ` <20091123224921.GA9654-f8uhVLnGfZaxAyOMLChx1axOck334EZe@public.gmane.org> 0 siblings, 1 reply; 7+ messages in thread From: Arnaldo de Melo @ 2009-11-23 22:49 UTC (permalink / raw) To: Mike Snitzer; +Cc: dwarves-u79uwXL29TY76Z2rM5mHXA Em Mon, Nov 23, 2009 at 05:17:03PM -0500, Mike Snitzer escreveu: > Hi, > > I just found out about pahole today. I'm looking to audit lvm2's data > structures and pahole is perfect for helping me do so. > > Unfortunately, when I run pahole against lvm2 I'm getting many BRAIN > FART ALERTs on F12 x86_64 (dwarves-1.7-5.x86_64). I had a look at your > OLS 2007 "7 dwarves" paper and figured I'd try your minimalist > swiss_cheese example, this is what I get: > > $ pahole swiss_cheese > struct cheese { > char name[17]; /* 0 17 */ > short int age; /* 0 2 */ > char type; /* 0 1 */ > int calories; /* 0 4 */ > short int price; /* 0 2 */ > int barcode[4]; /* 0 16 */ > > /* size: 48, cachelines: 1, members: 6 */ > /* padding: 32 */ > /* last cacheline: 48 bytes */ > > /* BRAIN FART ALERT! 48 != 17 + 0(holes), diff = 31 */ > > }; > > When I compare the above to the output listed in your paper it is clear > pahole is pretty unhappy on F12. If I do the same on F11 (x86_64) all > works fine. > > Should I open a fedora (F12) bug? You should, I think this is related to some recent elfutils changes that Mark Wieelard warned me about it but I hadn't time yet to act upon, will do so tomorrow, thanks for the report! Some milliseconds ago I was almost going to suggest you using the git version, but then I realized this is too strange to seem like something I could have fixed in the git repository :-\ That also should be another reason for me to do the f11->f12 step :-) Thanks! - Arnaldo -- To unsubscribe from this list: send the line "unsubscribe dwarves" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html ^ permalink raw reply [flat|nested] 7+ messages in thread
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* Re: pahole BRAIN FART ALERT on F12 [not found] ` <20091123224921.GA9654-f8uhVLnGfZaxAyOMLChx1axOck334EZe@public.gmane.org> @ 2009-11-23 22:56 ` Mike Snitzer [not found] ` <20091123225615.GD10860-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> 0 siblings, 1 reply; 7+ messages in thread From: Mike Snitzer @ 2009-11-23 22:56 UTC (permalink / raw) To: Arnaldo de Melo; +Cc: dwarves-u79uwXL29TY76Z2rM5mHXA On Mon, Nov 23 2009 at 5:49pm -0500, Arnaldo de Melo <acme-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> wrote: > Em Mon, Nov 23, 2009 at 05:17:03PM -0500, Mike Snitzer escreveu: > > Hi, > > > > I just found out about pahole today. I'm looking to audit lvm2's data > > structures and pahole is perfect for helping me do so. > > > > Unfortunately, when I run pahole against lvm2 I'm getting many BRAIN > > FART ALERTs on F12 x86_64 (dwarves-1.7-5.x86_64). I had a look at your > > OLS 2007 "7 dwarves" paper and figured I'd try your minimalist > > swiss_cheese example, this is what I get: > > > > $ pahole swiss_cheese > > struct cheese { > > char name[17]; /* 0 17 */ > > short int age; /* 0 2 */ > > char type; /* 0 1 */ > > int calories; /* 0 4 */ > > short int price; /* 0 2 */ > > int barcode[4]; /* 0 16 */ > > > > /* size: 48, cachelines: 1, members: 6 */ > > /* padding: 32 */ > > /* last cacheline: 48 bytes */ > > > > /* BRAIN FART ALERT! 48 != 17 + 0(holes), diff = 31 */ > > > > }; > > > > When I compare the above to the output listed in your paper it is clear > > pahole is pretty unhappy on F12. If I do the same on F11 (x86_64) all > > works fine. > > > > Should I open a fedora (F12) bug? > > You should, I think this is related to some recent elfutils changes that > Mark Wieelard warned me about it but I hadn't time yet to act upon, will > do so tomorrow, thanks for the report! > > Some milliseconds ago I was almost going to suggest you using the git > version, but then I realized this is too strange to seem like something > I could have fixed in the git repository :-\ > > That also should be another reason for me to do the f11->f12 step :-) Yes... embrace F12... :) BTW, I did try the latest git version from: git://git.kernel.org/pub/scm/linux/kernel/git/acme/pahole.git It didn't work either. Mike -- To unsubscribe from this list: send the line "unsubscribe dwarves" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html ^ permalink raw reply [flat|nested] 7+ messages in thread
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* Re: pahole BRAIN FART ALERT on F12 [not found] ` <20091123225615.GD10860-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> @ 2009-11-24 0:10 ` Arnaldo de Melo [not found] ` <20091124001047.GF15547-f8uhVLnGfZaxAyOMLChx1axOck334EZe@public.gmane.org> 0 siblings, 1 reply; 7+ messages in thread From: Arnaldo de Melo @ 2009-11-24 0:10 UTC (permalink / raw) To: Mike Snitzer; +Cc: dwarves-u79uwXL29TY76Z2rM5mHXA [-- Attachment #1: Type: text/plain, Size: 1329 bytes --] Em Mon, Nov 23, 2009 at 05:56:15PM -0500, Mike Snitzer escreveu: > On Mon, Nov 23 2009 at 5:49pm -0500, > Arnaldo de Melo <acme-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> wrote: > > Em Mon, Nov 23, 2009 at 05:17:03PM -0500, Mike Snitzer escreveu: > > > Unfortunately, when I run pahole against lvm2 I'm getting many BRAIN > > > FART ALERTs on F12 x86_64 (dwarves-1.7-5.x86_64). I had a look at your > > > OLS 2007 "7 dwarves" paper and figured I'd try your minimalist > > > swiss_cheese example, this is what I get: > > > $ pahole swiss_cheese > > > struct cheese { > > > char name[17]; /* 0 17 */ > > > short int age; /* 0 2 */ > > > char type; /* 0 1 */ <SNIP> > > > /* BRAIN FART ALERT! 48 != 17 + 0(holes), diff = 31 */ > > > }; > > You should, I think this is related to some recent elfutils changes that > > Mark Wieelard warned me about it but I hadn't time yet to act upon, will > > do so tomorrow, thanks for the report! > BTW, I did try the latest git version from: > git://git.kernel.org/pub/scm/linux/kernel/git/acme/pahole.git > It didn't work either. Can you try with the attached patch applied against the git repo version? Best Regards, - Arnaldo [-- Attachment #2: attr_offset.patch --] [-- Type: text/plain, Size: 794 bytes --] diff --git a/dwarf_loader.c b/dwarf_loader.c index 44605a8..3b58ecb 100644 --- a/dwarf_loader.c +++ b/dwarf_loader.c @@ -242,9 +242,23 @@ static Dwarf_Off attr_offset(Dwarf_Die *die, const uint32_t name) Dwarf_Attribute attr; Dwarf_Block block; - if (dwarf_attr(die, name, &attr) != NULL && - dwarf_formblock(&attr, &block) == 0) - return dwarf_expr(block.data, block.length); + if (dwarf_attr(die, name, &attr) == NULL) + return 0; + + switch (dwarf_whatform(&attr)) { + case DW_FORM_data1: + case DW_FORM_data2: + case DW_FORM_sdata: + case DW_FORM_udata: { + Dwarf_Word value; + if (dwarf_formudata(&attr, &value) == 0) + return value; + break; + } + default: + if (dwarf_formblock(&attr, &block) == 0) + return dwarf_expr(block.data, block.length); + } return 0; } ^ permalink raw reply related [flat|nested] 7+ messages in thread
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* Re: pahole BRAIN FART ALERT on F12 [not found] ` <20091124001047.GF15547-f8uhVLnGfZaxAyOMLChx1axOck334EZe@public.gmane.org> @ 2009-11-24 13:28 ` Mike Snitzer [not found] ` <20091124132831.GA31662-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> 0 siblings, 1 reply; 7+ messages in thread From: Mike Snitzer @ 2009-11-24 13:28 UTC (permalink / raw) To: Arnaldo de Melo; +Cc: dwarves-u79uwXL29TY76Z2rM5mHXA On Mon, Nov 23 2009 at 7:10pm -0500, Arnaldo de Melo <acme-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> wrote: > Em Mon, Nov 23, 2009 at 05:56:15PM -0500, Mike Snitzer escreveu: > > On Mon, Nov 23 2009 at 5:49pm -0500, > > Arnaldo de Melo <acme-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> wrote: > > > Em Mon, Nov 23, 2009 at 05:17:03PM -0500, Mike Snitzer escreveu: > > > > Unfortunately, when I run pahole against lvm2 I'm getting many BRAIN > > > > FART ALERTs on F12 x86_64 (dwarves-1.7-5.x86_64). I had a look at your > > > > OLS 2007 "7 dwarves" paper and figured I'd try your minimalist > > > > swiss_cheese example, this is what I get: > > > > $ pahole swiss_cheese > > > > struct cheese { > > > > char name[17]; /* 0 17 */ > > > > short int age; /* 0 2 */ > > > > char type; /* 0 1 */ > <SNIP> > > > > /* BRAIN FART ALERT! 48 != 17 + 0(holes), diff = 31 */ > > > > }; > > > You should, I think this is related to some recent elfutils changes that > > > Mark Wieelard warned me about it but I hadn't time yet to act upon, will > > > do so tomorrow, thanks for the report! > > > BTW, I did try the latest git version from: > > git://git.kernel.org/pub/scm/linux/kernel/git/acme/pahole.git > > It didn't work either. > > Can you try with the attached patch applied against the git repo > version? Works great, thanks! Would you still like me to file an F12 bug? Mike -- To unsubscribe from this list: send the line "unsubscribe dwarves" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html ^ permalink raw reply [flat|nested] 7+ messages in thread
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* Re: pahole BRAIN FART ALERT on F12 [not found] ` <20091124132831.GA31662-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> @ 2009-11-24 14:52 ` Arnaldo de Melo [not found] ` <20091124145212.GC9654-f8uhVLnGfZaxAyOMLChx1axOck334EZe@public.gmane.org> 0 siblings, 1 reply; 7+ messages in thread From: Arnaldo de Melo @ 2009-11-24 14:52 UTC (permalink / raw) To: Mike Snitzer; +Cc: dwarves-u79uwXL29TY76Z2rM5mHXA Em Tue, Nov 24, 2009 at 08:28:31AM -0500, Mike Snitzer escreveu: > On Mon, Nov 23 2009 at 7:10pm -0500, > Arnaldo de Melo <acme-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> wrote: > > Em Mon, Nov 23, 2009 at 05:56:15PM -0500, Mike Snitzer escreveu: > > > On Mon, Nov 23 2009 at 5:49pm -0500, > > > Arnaldo de Melo <acme-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> wrote: > > > > Em Mon, Nov 23, 2009 at 05:17:03PM -0500, Mike Snitzer escreveu: > > > > > Unfortunately, when I run pahole against lvm2 I'm getting many BRAIN > > > > > FART ALERTs on F12 x86_64 (dwarves-1.7-5.x86_64). I had a look at your > > > > > OLS 2007 "7 dwarves" paper and figured I'd try your minimalist > > > > > swiss_cheese example, this is what I get: > > > > > $ pahole swiss_cheese > > > > > struct cheese { > > > > > char name[17]; /* 0 17 */ > > > > > short int age; /* 0 2 */ > > > > > char type; /* 0 1 */ > > <SNIP> > > > > > /* BRAIN FART ALERT! 48 != 17 + 0(holes), diff = 31 */ > > > > > }; > > > > You should, I think this is related to some recent elfutils changes that > > > > Mark Wieelard warned me about it but I hadn't time yet to act upon, will > > > > do so tomorrow, thanks for the report! > > > > > BTW, I did try the latest git version from: > > > git://git.kernel.org/pub/scm/linux/kernel/git/acme/pahole.git > > > It didn't work either. > > > > Can you try with the attached patch applied against the git repo > > version? > > Works great, thanks! > > Would you still like me to file an F12 bug? Please, as I'll have to go the process for updating the package... :-) - Arnaldo -- To unsubscribe from this list: send the line "unsubscribe dwarves" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html ^ permalink raw reply [flat|nested] 7+ messages in thread
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* Re: pahole BRAIN FART ALERT on F12 [not found] ` <20091124145212.GC9654-f8uhVLnGfZaxAyOMLChx1axOck334EZe@public.gmane.org> @ 2009-11-24 15:18 ` Mike Snitzer 0 siblings, 0 replies; 7+ messages in thread From: Mike Snitzer @ 2009-11-24 15:18 UTC (permalink / raw) To: Arnaldo de Melo; +Cc: dwarves-u79uwXL29TY76Z2rM5mHXA On Tue, Nov 24 2009 at 9:52am -0500, Arnaldo de Melo <acme-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> wrote: > Em Tue, Nov 24, 2009 at 08:28:31AM -0500, Mike Snitzer escreveu: > > On Mon, Nov 23 2009 at 7:10pm -0500, > > Arnaldo de Melo <acme-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> wrote: > > > Em Mon, Nov 23, 2009 at 05:56:15PM -0500, Mike Snitzer escreveu: > > > > On Mon, Nov 23 2009 at 5:49pm -0500, > > > > Arnaldo de Melo <acme-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> wrote: > > > > > Em Mon, Nov 23, 2009 at 05:17:03PM -0500, Mike Snitzer escreveu: > > > > > > Unfortunately, when I run pahole against lvm2 I'm getting many BRAIN > > > > > > FART ALERTs on F12 x86_64 (dwarves-1.7-5.x86_64). I had a look at your > > > > > > OLS 2007 "7 dwarves" paper and figured I'd try your minimalist > > > > > > swiss_cheese example, this is what I get: > > > > > > $ pahole swiss_cheese > > > > > > struct cheese { > > > > > > char name[17]; /* 0 17 */ > > > > > > short int age; /* 0 2 */ > > > > > > char type; /* 0 1 */ > > > <SNIP> > > > > > > /* BRAIN FART ALERT! 48 != 17 + 0(holes), diff = 31 */ > > > > > > }; > > > > > You should, I think this is related to some recent elfutils changes that > > > > > Mark Wieelard warned me about it but I hadn't time yet to act upon, will > > > > > do so tomorrow, thanks for the report! > > > > > > > BTW, I did try the latest git version from: > > > > git://git.kernel.org/pub/scm/linux/kernel/git/acme/pahole.git > > > > It didn't work either. > > > > > > Can you try with the attached patch applied against the git repo > > > version? > > > > Works great, thanks! > > > > Would you still like me to file an F12 bug? > > Please, as I'll have to go the process for updating the package... :-) Done, please see RH bz # 540955 -- To unsubscribe from this list: send the line "unsubscribe dwarves" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html ^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2009-11-24 15:18 UTC | newest] Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2009-11-23 22:17 pahole BRAIN FART ALERT on F12 Mike Snitzer [not found] ` <20091123221703.GA10860-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> 2009-11-23 22:49 ` Arnaldo de Melo [not found] ` <20091123224921.GA9654-f8uhVLnGfZaxAyOMLChx1axOck334EZe@public.gmane.org> 2009-11-23 22:56 ` Mike Snitzer [not found] ` <20091123225615.GD10860-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> 2009-11-24 0:10 ` Arnaldo de Melo [not found] ` <20091124001047.GF15547-f8uhVLnGfZaxAyOMLChx1axOck334EZe@public.gmane.org> 2009-11-24 13:28 ` Mike Snitzer [not found] ` <20091124132831.GA31662-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> 2009-11-24 14:52 ` Arnaldo de Melo [not found] ` <20091124145212.GC9654-f8uhVLnGfZaxAyOMLChx1axOck334EZe@public.gmane.org> 2009-11-24 15:18 ` Mike Snitzer
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