>>>>> Jan Blunck (JB) writes: >> 1) i_sem protects dcache too
JB> Where? i_sem is the per-inode lock, and shouldn't be used else. read comments in fs/namei.c:read_lookup() >> 2) tmpfs has no "own" data, so we can use it this way (see 2nd patch) >> 3) I have pdirops patch for ext3, but it needs some cleaning ... JB> I think you didn't get my point. JB> 1) Your approach is duplicating the locking effort for regular filesystem JB> (like ext2): JB> a) locking with s_pdirops_sems JB> b) locking the low-level filesystem data JB> It's cool that it speeds up tmpfs, but I don't think that this legatimate the JB> doubled locking for every other filesystem. JB> I'm not sure that it also increases performance for regular filesystems, if you JB> do the locking right. we've already done this for ext3. it works. it speeds some loads up significantly. especially on big directories. and you can control this via mount option, so almost zero cost for fs that doesn't support pdirops. JB> 2) In my opinion, a superblock-wide semaphore array which allows 1024 JB> different (different names and different operations) accesses to ONE single JB> inode (which is the data it should protect) is not a good idea. yes, it has some weakness, i'm reworking vfs patch to avoid inter-inode collisions. thanks, Alex - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
