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Message-ID: <1423498049.31870.192.camel@edumazet-glaptop2.roam.corp.google.com> Date: Mon, 09 Feb 2015 08:07:29 -0800 From: Eric Dumazet <eric.dumazet@...il.com> To: Bryton Lee <brytonlee01@...il.com> Cc: stephen@...workplumber.org, netdev@...r.kernel.org Subject: Re: [PATCH] prevent the read ahead of /proc/slabinfo in ss On Mon, 2015-02-09 at 19:37 +0800, Bryton Lee wrote: > ss reads ahead of /proc/slabinfo whatever slabstat will be used or not in future. > this will cause huge system delay when the kernel hires SLAB allocator(SLUB allocator is ok). when program reads > /proc/slabinfo, it will call s_show() in SLAB allocator level, and s_show() calls spin_lock_irq(&l3->list_lock) > then iterate on whole three lists. if one slab has about 900 million objects (for example dentry), > it will cause more than 1000ms delay. > > so this patch prevents the read ahead of /proc/slabinfo, ss runs with most parameters not using slabstat at all. Indeed, thanks ! Acked-by: Eric Dumazet <edumazet@...gle.com> -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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