[LU-191] mdd_close will always start transaction even atime is not changed

• Status: Resolved
• Project: Lustre
• Affects Version/s: Lustre 2.1.0
• Fix Version/s: Lustre 2.1.0
• Type: Bug
• Priority: Minor
• Reporter: Liang Zhen (Inactive)
• Assignee: Liang Zhen (Inactive)
• Resolution: Fixed
• Severity: 3

Description

I've fixed this in bug 23289 (attachment 32253), however it's back after landing of another patch (bug 23291, attachment 31108):

• if (la->la_atime <= tmp_la->la_atime +
• mdd_obj2mdd_dev(obj)->mdd_atime_diff)
  + if (la->la_atime > tmp_la->la_atime &&
  + la->la_atime <= (tmp_la->la_atime +
  + mdd_obj2mdd_dev(obj)->mdd_atime_diff))
  la->la_valid &= ~LA_ATIME;

with this patch, the condition is always false if "la->la_atime == tmp_la->la_atime", which means even atime is exactly same as before, we still start a transaction and setattr, this will give a big impact on performance for those shortly open+close applications/tests.

Comments

[Mikhail Pershin]

so that is enough to use >= in first check and maybe just < in second, right?

[Liang Zhen (Inactive)]

exactly,

[Build Master (Inactive)]

Integrated in reviews-centos5 #650
LU-191 mdd_close always set atime even it's same

Liang Zhen : 505ae6ff13b72df8d6db1627ee509398b91c8fd2
Files :

• lustre/mdd/mdd_object.c

[Build Master (Inactive)]

Integrated in lustre-master-centos5 #201
LU-191 mdd_close always set atime even it's same

Oleg Drokin : d65f789f433f2d52e82116c374d88906321f9d28
Files :

• lustre/mdd/mdd_object.c

[Build Master (Inactive)]

Integrated in lustre-master » client,ubuntu-x86_64 #29
LU-191 mdd_close always set atime even it's same

Oleg Drokin : d65f789f433f2d52e82116c374d88906321f9d28
Files :

• lustre/mdd/mdd_object.c

[Build Master (Inactive)]

Integrated in lustre-master » client,el5-x86_64 #29
LU-191 mdd_close always set atime even it's same

Oleg Drokin : d65f789f433f2d52e82116c374d88906321f9d28
Files :

• lustre/mdd/mdd_object.c

[Build Master (Inactive)]

Integrated in lustre-master » client,el5-i686 #29
LU-191 mdd_close always set atime even it's same

Oleg Drokin : d65f789f433f2d52e82116c374d88906321f9d28
Files :

• lustre/mdd/mdd_object.c

[Build Master (Inactive)]

Integrated in lustre-master » server,el6-x86_64 #29
LU-191 mdd_close always set atime even it's same

Oleg Drokin : d65f789f433f2d52e82116c374d88906321f9d28
Files :

• lustre/mdd/mdd_object.c

[Build Master (Inactive)]

Integrated in lustre-master » client,el6-i686 #29
LU-191 mdd_close always set atime even it's same

Oleg Drokin : d65f789f433f2d52e82116c374d88906321f9d28
Files :

• lustre/mdd/mdd_object.c

[Build Master (Inactive)]

Integrated in lustre-master » server,el5-x86_64 #29
LU-191 mdd_close always set atime even it's same

Oleg Drokin : d65f789f433f2d52e82116c374d88906321f9d28
Files :

• lustre/mdd/mdd_object.c

[Build Master (Inactive)]

Integrated in lustre-master » client,el6-x86_64 #29
LU-191 mdd_close always set atime even it's same

Oleg Drokin : d65f789f433f2d52e82116c374d88906321f9d28
Files :

• lustre/mdd/mdd_object.c

[Build Master (Inactive)]

Integrated in lustre-master » server,el5-i686 #29
LU-191 mdd_close always set atime even it's same

Oleg Drokin : d65f789f433f2d52e82116c374d88906321f9d28
Files :

• lustre/mdd/mdd_object.c

[Liang Zhen (Inactive)]

patch already landed in master